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  • Lepidoptera  (475)
  • Electron microscopy  (252)
  • Springer  (727)
  • Periodicals Archive Online (PAO)
  • 1985-1989  (421)
  • 1980-1984  (306)
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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular evolution 26 (1987), S. 347-357 
    ISSN: 1432-1432
    Keywords: Ribosome structure ; Electron microscopy ; Image analysis ; Evolutionary lineages
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Multivariate statistical analysis and classification techniques are powerful tools in sorting noisy electron micrographs of single particles according to their principal features, enabling one to form average images with an enhanced signal-to-noise ratio and a better reproducible resolution. We apply this methodology here to determining the characteristic views of the large (50S) ribosomal subunits from the eubacteriumEscherichia coli and the archaebacteriaMethanococcus vannielii, Sulfolobus solfataricus, andHalobacterium marismortui. Average images were obtained of the subunit in the common crown and kidney projections, but views of the particle in orientations intermediate between these two extremes were also elucidated for all species. These averages show reproducible detail of up to 2.0 nm resolution, thus enabling the visualization and interspecies comparison of many structural features as a first step toward comparing the actual three-dimensional structures. Our results disprove evolutionary lineages recently postulated on the basis of electron microscopical images of ribosomal subunits.
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  • 2
    ISSN: 1432-1939
    Keywords: Lepidoptera ; Salicaceae ; Herbivory ; Resource allocation ; Chemical defense
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The cottonwood tree, Populus deltoides, continues to produce leaves late into the growing season, exposing midseason herbivores to leaves of a wide range of maturity. Gypsy moth larvae preferred and grew best on the oldest cottonwood leaves and suffered higher mortality and 85% less growth when fed young, expanding leaves. Concentration of phenolics in the youngest leaves was 3 times that in the oldest leaves and was negatively correlated with caterpillar growth rate. The active phenolics were not identified; tannin was present but its concentration changed more with season than leaf age.
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  • 3
    ISSN: 1432-1939
    Keywords: Iridomyrmex humilis ; Predation ; Host range ; Prey acceptability ; Lepidoptera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Experiments are described which test the hypothesis that more host-specific species of caterpillars should be less aceptable to a generalist predator than polyphagous species. Caterpillars of all species were tested in paired choice tests with the Argentine ant, Iridomyrmex humilis. Experiments were replicated ten times, videotaped and later analyzed. Brightly colored specialist species (normally considered to be aposematic) were clearly the least palatable, while more cryptic specialists were also significantly less acceptable than generalists overall. Leaf-tying species were considered separately; all were highly palatable independent of host range. The results indicate that among caterpillars that do not construct leaf shelters, those with a wide post range are more acceptable than those with a narrow host range. This is consistent with the notion that generalist predators provide selection pressure favoring narrow host range in their herbivorous prey.
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  • 4
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    Oecologia 70 (1986), S. 205-213 
    ISSN: 1432-1939
    Keywords: Parnassius ; Lepidoptera ; Radiation ; Temperature ; Melanism ; Thermoregulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The adaptive significance of alpine melanism, the tendancy for insects to become darker with increased elevation and latitude, was investigated using the butterfly Parnassius phoebus. The effects on temperature dependent activity of five components of overall wing melanism, as well as size, were examined. The components of wing melanism examined were the transparency of the basal hindwing and distal fore-wing areas, the width of the black patch in the basal hind-wing area and the proportion of black to white scales in that area, and the proportion of the distal fore-wing covered by predominantly black scaling. The body temperature of dead specimens was correlated with air temperature, solar radiation, the width of the black patch at the base of the wings, and the proportion of black to white scales at the base of the wings. The minimum air temperatures and solar radiation levels required for initiation of flight did not vary with wing melanism of P. phoebus, in contrast to the results found for Colias butterflies by Roland (1982). However, under environmental conditions suitable for flight initiation, males with a higher proportion of black to white scales in the basal area of the hind-wing, and wider basal black patches, spent a greater proportion of time in flight at low air temperatures and low insolation. Increased basal wing melanism was also associated with increased movement of males within a population. In contrast, melanism in the distal area of the wings has no effect on activities which are dependant on body temperature. The amount of time spent feeding did not vary with differences in wing melanism. I suggest that in dorsal basking, slow-flying butterflies (Parnassius) basal wing color affects body temperature primarily during flight (rather than while basking), such that butterflies with darker wing bases cool down less rapidly because they absorb more solar radiation during flight.
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  • 5
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    Oecologia 78 (1989), S. 214-219 
    ISSN: 1432-1939
    Keywords: Asimina ; Facilitation ; Defoliation ; Herbivory ; Lepidoptera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Insect herbivores that require young foliage for successful larval development are often restricted to a single generation during a year by the scarcity of suitable food over most of the growing season. The major specialist herbivore attacking shrubs in the genus Asimina in Florida, Eurytides marcellus, requires young foliage for successful larval development. Field manipulations were used to investigate the role of the young foliage produced by Asimina in response to defoliation by the late-season feeder Omphalocera munroei, a second specialist herbivore of Asimina in Florida, in maintaining Eurytides populations during the summer months when young foliage is otherwise scarce. Defoliation by Omphalocera proved to be the major inducer of young growth during the summer because Omphalocera defoliated Asimina shrubs so frequently and severely. When compared to young leaves produced in the absence of damage, the teaves produced by Asimina in response to defoliation were equally as suitable as food for Eurytides larvae and as acceptable as oviposition sites by Eurytides females. The availability of young foliage in an Asimina population was correlated with the size of the associated Eurytides population. The combination of regular, severe defoliation by Omphalocera and lack of a defensive response to damage by Asimina lead to a positive affect of Omphalocera on Eurytides population size, and may be central to other facilitative interactions between herbivores as well.
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  • 6
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    Springer
    Calcified tissue international 33 (1981), S. 119-124 
    ISSN: 1432-0827
    Keywords: Avian eggshell ; Microstructure ; Electron microscopy ; Electron diffraction ; Calcite growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The eggshell of the domestic fowl has been studied by transmission electron microscopy and diffraction. Thin sections of shell were prepared by chemical and ion-beam thinning techniques. Each calcite column of the palisade layer consisted of crystallites of diameter 20 to 30 µm with some tendency for crystallite alignment within a single column. Evidence indicates that there was no significant preferred orientation in the palisade layer as a whole. Only in the surface layer was any preferred orientation detected, and here {1014} planes tended to lie parallel to the surface. The results are compared with previously published data, and calcite nucleation and growth are discussed.
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  • 7
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    Calcified tissue international 30 (1980), S. 43-50 
    ISSN: 1432-0827
    Keywords: Osteogenesis ; In vitro ; Electron microscopy ; Mineralization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Chick limb mesenchymal cells differentiate into muscle, cartilage, fibrous, and bone tissue. Previous reports show that when stage 24 limb mesenchymal cells are cultured in vitro, chondrocytes, myocytes, fibrocytes, and osteoblasts can be identified on the basis of morphological and biochemical parameters. The study reported here demonstrates that phenotypic expression in culture seems to be dependent on the initial plating density, Scanning electron microscopic observations indicate that when stage 24 limb mesenchymal cells are initially seeded at high densities (5 × 106 cells per 35 mm culture dish), mounds of cells appear in culture. These mounds represent cartilage nodules composed of a fine fibrous matrix and chondrocytes, surrounded by a loose fibrous connective tissue matrix. Cultures initially plated at intermediate densities (2.0–2.5 × 106 cells/35 mm culture dish) produce a flattened layer of fibrocytes overlying a matrix of collagen fibers and calcium phosphate deposits as determined by electron-microprobe analysis; these observations are indicative of osteoblast expression. Cells seeded at this intermediate density appear larger and possess greater surface area than cells seeded at high density. It is suggested that conditions that permit such increased cell surface area coupled with a relative compaction due to cell crowding may provide conditions permissive for osteogenesis. Based on morphological criteria, it appears that chick limb mesenchymal cell osteogenesis in vitro is not associated with chondrogenesis but represents a separate route of phenotypic expression.
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  • 8
    ISSN: 1432-0827
    Keywords: Decalcification ; Electron microscopy ; Bone matrix ; Bone glycoproteins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary A solution of triethylammonium EDTA in 80% ethanol was evaluated as a demineralizing reagent for bone in comparison with aqueous solutions of EDTA. Biochemical analysis and acrylamide gel electrophoresis of extracts of finely powdered bovine bone showed that most of the macromolecular components of the organic matrix extractable in aqueous EDTA were retained when the triethylammonium EDTA reagent was used. Ultrastructural examination of chick tibias decalcified with the reagents showed a better preservation of cellular morphology, especially the membranous components, and more uniformly distributed ground substance, though slightly less in quantity, when the aqueous reagent was used. Use of the two reagents appears to be complementary, the alkylammonium reagent being more appropriate for use in studies of the organic matrix of bone, including immunohistochemical studies of bone glycoproteins. The aqueous reagent is more appropriate for use in studies of cellular ultrastructure.
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  • 9
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    Calcified tissue international 33 (1981), S. 143-151 
    ISSN: 1432-0827
    Keywords: Calcium transport ; Cytochalasin B ; Dihydrocytochalasin B ; Colchicine ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary In vivo calcium absorption was studied in normal and rachitic chicks. Cytochalasin B (CB) at a concentration of 25 µg/ml added to the medium inside the duodenal lumen inhibited calcium absorption (20 min) from 82.5±1.9% of calcium absorbed in the controls to 59.2±3% in normal and from 70.0±2.3% to 47.0±2.1% in rachitic chicks. In vitro studies by everted ileal sacs of young rabbits also showed an inhibition of active transport of calcium due to CB. Whereas in the controls the ratio of45Ca concentrations in serosal and mucosal media (60 min) was 7.2±0.32, the ratios were 5.24±0.52; 4.40±0.36; 3.40±0.42; 5.77±0.52; 1.38±0.08; and 1.06±0.02 in the presence of CB at concentrations of 5, 10 and 25 µg/ml; colchicine 10−4M, Na citrate 0.02M, and heat-devitalized conditions, respectively.45Ca concentration in the mucosal scrapings was also affected. It showed an increase from controls (15,101±404 cpm/mg) and correlated with CB concentration: 17,378±489, 19,015±1000, and 20,201±362 at 5, 10, and 25 µg/ml, respectively. Dihydrocytochalasin B also inhibited active calcium transport and caused an increase in45Ca concentration in the mucosal scrapings. Correlated electron microscopic studies showed certain changes in the brush border, especially in some actin microfilaments in the terminal web region. It seems that these morphological alterations may be related to transcytoplasmic movement of calcium.
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  • 10
    ISSN: 1432-0827
    Keywords: Alcohol ; Electron microscopy ; Growth plate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary We have previously demonstrated that ethanol has a direct toxic effect on the rat skeleton characterized by decreased trabecular bone volume. In the present study, we examined the ultrastructure of the distal radial epiphyseal growth plates in these same animals. Eight weeks of ethanol administration to 12 male rats results in serum alcohol levels of 140 mg/dl but did not alter the width or light microscopic appearance of the radial growth plate. Quantitative electron microscopy failed to demonstrate morphologic evidence of toxicity in the skeletal cells. We conclude that although ethanol appears to have a direct effect on rat bone characterized by enhanced resorption, toxicity is not attended by ultrastructural changes in the skeletal cells.
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  • 11
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    Calcified tissue international 33 (1981), S. 529-540 
    ISSN: 1432-0827
    Keywords: Bone cells ; Electron microscopy ; PTH ; PGE1
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Four different cell populations—designated PF, OB, OC, and PC—were isolated from calvaria of 18-day-old chick embryos for analysis of the effects of hormones on bone tissue. The cell populations were studied with histological and biochemical methods. Apart from the well-known cell types present in calvaria, a new cell type was found in the noncalcified organic matrix between the osteoblastic layer and the calcified matrix. These cells were provisionally called osteocytic osteoblasts. They represent the “transition state” between osteoblasts and osteocytes. On the basis of histological studies with light microscopy (LM), transmission electron microscopy (TEM) and scanning electron microscopy (SEM), the PF population was considered to originate primarily from the periosteal fibroblasts, the OB population from the osteoblasts and osteocytic osteoblasts. The population of cells still present in calvaria after removal of periosteal fibroblasts and osteoblasts was called the OC population. This cell population was very much enriched with osteocytes. The fourth isolated population (PC) was a mixed population of fibroblasts, osteoblasts, and preosteoblasts. On exposure to parathyroid hormone (PTH), all four cell populations showed increased lactate production, but only the OB and OC populations displayed increased cAMP production. Prostaglandin E1 (PGE1) stimulated cAMP production in both OB and PF cells. From the results of this study it was concluded that PTH receptors are present on all of the cell types studied, but that occupancy of the receptor induces adenylate cyclase stimulation only in osteocytes and fully differentiated osteoblasts.
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  • 12
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    Cellular and molecular life sciences 41 (1985), S. 267-269 
    ISSN: 1420-9071
    Keywords: Diapause ; oligopause ; sugarcane borer ; Diatraea saccharalis ; Lepidoptera ; Pyralidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Sugarcane borers enter a state of delayed metamorphosis when exposed to a 12-h photophase at 21°C. Larval feeding, growth, and molting continues but pupation is suppressed under these conditions.
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  • 13
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    Cellular and molecular life sciences 45 (1989), S. 236-240 
    ISSN: 1420-9071
    Keywords: Lepidoptera ; semiochemicals ; sex pheromones ; host plants ; secondary plant compounds ; calling behaviour ; mate choice ; Homoesoma electellum ; Pseudaletia unipuncta
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The role of host plants in the synthesis and release of lepidopteran sex pheromones is examined. Females synthesise pheromones de novo and pheromone quality is not markedly influenced by larval food sources. However, host plants may have a significant effect on different physiological and behavioural parameters associated with pheromone production. Males in some species of Nymphalidae and Arctiidae use secondary plant compounds, such as pyrrolizidine alkaloids, as a pheromone precursor. In such cases these plant compounds serve an additional role, such as protection against predation, and may reflect potential male reproductive investment. In the one instance where the effect of larval host plants on the de novo synthesis of a male sex pheromone was examined, larval nutrition did not alter either the quality or quantity of the hairpencil contents.
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  • 14
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    Cellular and molecular life sciences 41 (1985), S. 24-29 
    ISSN: 1420-9071
    Keywords: Pieridae ; Lepidoptera ; systematics ; evolution ; enzyme electrophoresis ; genetic differentiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Enzyme electrophoretic data show a remarkably high degree of genetic similarity within the European group ofnapi s.l. whereas genetic differences exist at several loci between the European and the North American taxa ofnapi s.l. It is concluded that the European taxa did not differentiate to the species level and form a phylogenetically young group. The North American taxa included in this study are specifically distinct from Europeannapi and separated much earlier. Within these North American taxamarginalis, oleracea andvirginiensis did undergo speciation. The data show a splitting of the genusPieris into three species groups, each genetically differentiated to the same level. The splitting ofPieris into two genera, as suggested by earlier investigators, is not supported here.
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  • 15
    ISSN: 1420-9071
    Keywords: Acid fluoride ; aldehyde ; mating disruption ; pheromone analogs ; Heliothis ; Lepidoptera ; fluorination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Substitution of fluorine for the aldehydic hydrogen provides behaviorally active, chemically reactive pheromone mimics. In male moths of the tobacco budwormHeliothis virescens, Z9–14:Acf and Z11–16:Acf cause hyperactivity and irreversible extension of the genitalia in over 80% of treated moths. In addition, a combination of the two components leads to 10–50% of the pairs involving one treated partner becoming locked in copula.
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  • 16
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    Cellular and molecular life sciences 42 (1986), S. 448-450 
    ISSN: 1420-9071
    Keywords: Lepidoptera ; Acrolepiopsis assectella ; host plant ; larval diet ; ovarian production ; stimulation ; insemination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Females ofAcrolepiopsis assectella, reared on a semi-synthetic diet and laying on artificial substrates, do not respond to external stimuli by increasing ovarian production. When returned to the natural host (Allium porrum) for only one generation, ovarian production again rises and reaches the same level as in wild females, but its variability is strongly reduced. We conclude that selection under artificial conditions eliminates individuals which strictly depend on host plants for stimulation of larval nutrition and of reproduction.
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  • 17
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    Cellular and molecular life sciences 45 (1989), S. 229-236 
    ISSN: 1420-9071
    Keywords: Lepidoptera ; Orthoptera ; digestive efficiency ; allelochemistry ; cytochrome P450 ; nutrition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Adaptation to a phytophagous diet involves physiological compromises that may be influenced by developmental constraints. In this review, we compare patterns of hostplant utilization with respect to nutrition and allelochemistry in representative holometabolous (lepidopteran) and hemimetabolous (orthopteran) species in order to identify those potential constraints. Overall in Lepidoptera greater molting efficiency and gut permeability, which enhance nutritional efficiency, result in higher exposure to allelochemicals and are associated with greater activity and inducibility of cytochrome P450 monoxygenase detoxication enzymes. In contrast, in Orthoptera, relative impermeability to allelochemicals due to the peritrophic membrane and cuticular sclerotization is associated with reduced nutritional efficiency and lower detoxication enzyme activity.
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  • 18
    ISSN: 1420-9071
    Keywords: 4″-Amino-4″-deoxyavermectins ; avermectin ; insecticide ; Lepidoptera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A new class of insecticidal and antiparasitic agents, 4″-amino-4′-deoxy avermectins, has been developed by chemical modification of avermectin B1. The most effective of these compounds are 1500-fold more potent than avermectin B1 (abamectin) against the beet armywormSpodoptera exigua and show similar potency against other lepidopteran larvae.
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  • 19
    ISSN: 1420-9071
    Keywords: Cyanogenesis ; β-glucosidase ; Lepidoptera ; linamarin ; linamarase ; lotaustralin ; repellent ; Zygaenidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A β-glucosidase (linamarase) was purified 52-fold with a recovery of 27% from the haemolymph of the larvae ofZygaena trifolii, ESPER, 1783 (Lepidoptera, Zygaenidae). The final enzyme preparation was found to be nearly homogeneous on both disc polyacrylamide gel electrophoresis and SDS-polyacrylamide gel electrophoresis. The molecular weight of the enzyme was determined to be about 130 kDa; it consisted of two subunits of about 66 kDa. The enzyme showed an optimum between pH 4.5 and 5 with linamarin and a broad optimum between pH 3.5 and 6.5 for p-nitrophenyl-β-D-glucoside; the temperature optimum was 40°C. The β-glucosidase showed a high specificity for its endogenous substrates linamarin and lotaustralin. Among the other natural and artificial substrates tested, only prunasin and p-nitrophenyl-β-D-glucoside were hydrolyzed by the enzyme, whereas linustatin, salicin, cellobiose and trehalose were not. The enzyme is strongly inhibited by β-glucosylpiperidine.
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  • 20
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    Cellular and molecular life sciences 42 (1986), S. 1059-1061 
    ISSN: 1420-9071
    Keywords: Pheromone ; Lepidoptera ; Agrotis segetum ; biosynthesis ; palmitic acid ; capillary gas chromatography ; deuterium ; polyethylene glycol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary (16-D3)palmitic acid was applied topically to pheromone glands of the turnip moth. After incubation omega labeled analogues of fatty acid methyl esters and acetates were identified by gas chromatography with flame ionization detection and selected ion monitoring. The pheromone components (Z)-5-decenyl, (Z)-7-dodecenyl- and (Z)-9-tetradecenyl acetate were all biosynthesized from palmitic acid along a common pathway.
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  • 21
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    Cellular and molecular life sciences 44 (1988), S. 788-789 
    ISSN: 1420-9071
    Keywords: Yponomeuta vigintipunctatus ; Lepidoptera ; Yponomeutidae ; diapause ; photoperiodic induction curves ; low temperature influence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The long-day insectYponomeuta vigintipunctatus was subjected to various combinations of temperature and photoperiod. The photoperiodic induction curve at 10°C resembled the one at 20°C, but with a shift of the critical photoperiod towards the shorter day-length. Such unusual averting of diapause at lower temperatures in combination with intermediate long-day photoperiods has still been described in only few insect species of the temperate zone.
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  • 22
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    Cellular and molecular life sciences 45 (1989), S. 81-87 
    ISSN: 1420-9071
    Keywords: Lepidoptera ; Bombyx mori L ; moths ; antennae ; pheromones ; metabolites ; enzymes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In living antennae of the silkworm mothBombyx mori L. the pheromone compound (E, Z)-10,12-hexadecadienol and hexadecanol are enzymatically converted to their corresponding fatty aldehydes, acids and long-chain fatty acid esters. The pheromone is completely degraded at high rates in the antennae of freshly hatched moths. The polar volatile [3H]metabolites exclusively consist of tritiated water. The half-life of the pheromone is about 2.5 min in males and 0.5 min in females. Drying inactivates the enzymes responsible for pheromone oxidation.
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  • 23
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    Cellular and molecular life sciences 45 (1989), S. 896-898 
    ISSN: 1420-9071
    Keywords: Lepidoptera ; pyrrolizidine alkaloid ; pheromone ; sexual selection ; nuptial gift ; egg defense
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Pyrrolizidine alkaloid sequestered by adult maleDanaus gilippus from plants is transferred in large measure to the female at mating, and by the female to the eggs. The eggs, presumably, are protected as a result. The male's courtship pheromone, danaidone, derived from the sequestered alkaloid, may function to advertise the male's alkaloid-donating capacity.
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  • 24
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    Cellular and molecular life sciences 43 (1987), S. 943-946 
    ISSN: 1420-9071
    Keywords: Pyrrolizidine alkaloids ; macrocyclic diesters ; monoesters ; dihydropyrrolizines ; Lepidoptera ; Danaus plexippus ; monarch butterflies ; overwintering ; asteraceae ; Boraginaceae ; ecological chemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary North American populations of the monarch butterfly,Danaus plexippus, have been found to contain pyrrolizidine alkaloids and their N-oxides. Analytical methods (TLC, GC, and GC/MS) have been developed to isolate, quantitate, and structurally elucidate the alkaloids. Examples of at least two classes of pyrrolizidine alkaloids have been identified, the macrocyclic diesters, senecionine, integerrimine, and seneciphylline, and the monoesters, echinatine, intermedine, and lycopsamine.
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  • 25
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    Cellular and molecular life sciences 45 (1989), S. 580-583 
    ISSN: 1420-9071
    Keywords: Thiosemicarbazones ; anti-juvenile hormone ; insect growth regulator ; Lepidoptera ; juvenile hormone biosynthesis inhibitor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A new class of anti-juvenile hormone agents is described. Active anti-juvenile hormone compounds were either diazine thiosemicarbazones or aryl substituted pyridyl thiosemicarbazones, synthesized from substituted benzaldehydes. While many analogs in these classes showed feeding and growth inhibition in a variety of insects, a select group caused formation of precocious pupal characteristics inAgrotis ipsilon (black cutworm) andHeliothis virescens (tobacco budworm) and black cuticle and precocious pupae inManduca sexta (tobacco hornworm). They were active only by diet incorporation. The symptoms of precocious development could be reversed by co-administration of a juvenoid. One of the active compounds was shown to inhibit juvenile hormone biosynthesis in vitro by corpora allata of the cockroachDiploptera punctata. However, none of the compounds were active inhibitors of purified chicken liver prenyl transferase.
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  • 26
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    Development genes and evolution 191 (1982), S. 205-207 
    ISSN: 1432-041X
    Keywords: Chitin inhibition ; Nikkomycin ; Cuticle ; Electron microscopy ; Epilachna varivestis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The nucleoside antibiotic nikkomycin has proved to be an effective inhibitor of chitin synthesis in the Mexican bean beetleEpilachna varivestis. Ultrastructural investigations show defects in the procuticular area after nikkomycin application which suggest the complete absence of chitin. A cuticle like this is inflexible and too brittle to satisfy its normal function as an exoskeleton. The individuals are not able to free themselves from the exuvia and finally die. Therefore nikkomycin seems to be a potential insecticide with high specifity.
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  • 27
    ISSN: 1432-0827
    Keywords: Rat ; Calvarium ; Electron microscopy ; Preosteoclasts ; Osteoclasts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary This is a study of the fine structure of cells of the 20-day fetal rat calvarium. Special attention is given to identifying and characterizing preosteoclasts. These cells are relatively common and located largely, but not exclusively, at the endocranial bone surface. The preosteoclasts are characterized by abundant mitochondria, an incomplete perinuclear Golgi apparatus, and variable-shaped dense granules. The dense granules are unique in appearance in that they contain an internal dense matrix surrounded by a clear halo. Most granules are circular in shape but some are elongate or tubular in form. Granules with identical appearance are observed in osteoclasts. The preosteoclasts are mononucleate, or occasionally binucleate. It is suggested that because preosteoclasts are morphologically distinctive and relatively abundant, it should be feasible to separate these cells from a heterogeneous cell isolate.
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  • 28
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    Archives of microbiology 126 (1980), S. 277-283 
    ISSN: 1432-072X
    Keywords: Bacteriophage ; Myxococcus ; λ ; Superooiled DNA ; Cross-linking ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract DNA was partially released from the heads of myxococcus phages and also coliphage λ and examined by electron microscopy by a modification of the Kleinschmidt technique, in which water was used as hypophase. DNA emerged from the heads in patterns suggestive of newly relaxed supercoils. The unreleased DNA appeared to occupy discrete regions in the head. Some closed circles were released from λ heads. When NaCl solution was used as hypophase, the DNA was observed either released from the tail or from the head, in the latter case, supercoiled regions were observed. When NH4OAc solution was used as hypophase, tightly wound structures were released from λ heads; these fields also contained supercoiled circles. The presence of constrained supercoiled domains in newly released phage DNA was confirmed by observing the effects of ethidium bromide on its conformation. Treatment of phage with nitrogen mustard, a bifunctional alkylating agent, preserved supercoiled domains, even when the phage were lysed over water as hypophase. Further experiments suggested that phage inactivation by nitrogen mustard is largely due to restraint of the supercoiled, native, tertiary structure and that DNA-protein cross-linking may be involved in this reaction. The implications of these findings for the conformation of phage DNA in vivo are discussed and a new model for the winding of DNA in phage heads is proposed.
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  • 29
    ISSN: 1432-072X
    Keywords: Allomyces ; Zoospores ; Cell wall ; Chitin ; Gamma particle ; Encystment ; Electron microscopy ; Calcofluor
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    Topics: Biology
    Notes: Abstract Structural changes during cell wall formation by populations of semisynchronously germinating zoospores were studied in the water mold Allomyces macrogynus. Fluorescence microscopy using Calcofluor white ST (which binds to β-1,4-linked glycans) demonstrated that Calcofluor-specific material was deposited around most cells between 2–10 min after the induction of encystment (beginning when a wall-less zoospore retracts its flagellum and rounds up). During the first 15 min of encystment there was a progressive increase in fluorescence intensity. Ultrastructural analysis of encysting cells showed that within 2–10 min after the induction of encystment small vesicles 35–70 nm diameter were present near the spore surface, and some were in the process of fusing with the plasma membrane. The fusion of vesicles with the zoospore membrane was concomitant with the appearance of electron-opaque fibrillar material outside the plasma membrane. Vesicles similar to those near the spore surface were found within the gamma (γ) particles of encysting cells. These particles had a crystalline inclusion within the electron-opaque matrix. During the period of initial cyst cell wall formation numerous vesicles appeared to arise at the crystal-matrix interface. Approximately 15–20 min was required for the cell wall to be formed. We suggest that the initial response of the zoospore to induction of encystment is the formation of a cell wall mediated by the fusion of cytoplasmic vesicles with the plasma membrane.
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  • 30
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    Archives of microbiology 129 (1981), S. 129-134 
    ISSN: 1432-072X
    Keywords: Cockroach ; Hindgut ; Distribution ; Microbial morphotypes ; Transmission ; Electron microscopy ; Statistical analysis ; Eublaberus posticus
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    Topics: Biology
    Notes: Abstract The relative numbers of fourteen microbial morphotypes in transmission electron micrographs of the hindgut of a cockroach, Eublaberus posticus, were counted and their distribution was analyzed statistically. The microbiota of three wall-associated regions (the anterior paunch, the posterior paunch, and the black band region) was clearly different from that of the gut lumen. The three wall fractions were also significantly different from each other. Only one of the fourteen types, prosthecate bacteria, appeared to be distributed randomly in the four fractions. The five main wall-associated morphotypes individually constituted up to 41% of the microbes in some micrographs. They included one type with the characteristic morphology of Methanospirillum. Six morphotypes rarely made up over 2% of the population, but were consistently present. The numbers of the remaining three morphotypes were quite variable between micrographs and between individual insects, but when present often made up 5–10% of the population.
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  • 31
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    Archives of microbiology 133 (1982), S. 97-99 
    ISSN: 1432-072X
    Keywords: Cyanobacteria ; Thylakoid centers ; Photosynthetic membranes/thylakoids ; Membranes ; Membrane biogenesis ; Electron microscopy
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    Notes: Abstract An ultrastructural study of four cyanobacteria (Anabaena cylindrica, Dermocarpa violaceae, Gleocapsa alpicola, Pleurocapsa minor) indicates the presence of previously undescribed thylakoid centers from which photosynthetic membranes (thylakoids) radiate. These peripherally located thylakoid centers are cylinders 30 nm wide by 320 nm long, consisting of globular subunits oriented in nonparallel stacked arrays. Thylakoids are attached to the outer surface of the cylinder along its longitudinal axis. Thylakoid centers appear to be functionally significant due to their structure, location and thylakoid association.
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  • 32
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    Archives of microbiology 130 (1981), S. 339-343 
    ISSN: 1432-072X
    Keywords: Leptospira ; Halophilic ; Electron microscopy ; X-ray analysis ; Inclusions ; Cytoplasmic tubules
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    Topics: Biology
    Notes: Abstract The morphology of cells of strain Muggia, a slightly halophilic leptospire, was examined by the negative staining technique. The ultrastructure of the cells was rather similar to that of cells of Leptonema illini, i. e. the cells possessed cytoplasmic tubules. The basal complex of their flagella, however, was similar to the corresponding part of flagella on Gramnegative bacteria. The interior of the cells was densely packed with inclusions, except for the two outermost wavelengths at each end where these inclusions were absent. X-ray microanalysis showed that the inclusions contained sodium and chlorine as their main constituents. The inclusions disappeared upon storage of the cultures at room temperature.
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  • 33
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    Keywords: Ribulose bisphosphate carboxylase ; Quaternary structure ; Molecular weight ; Electron microscopy ; Cyanobacteria ; Synechococcus
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    Topics: Biology
    Notes: Abstract Ribulose bisphosphate (RuP2) carboxylase from the marme cyanobacterium, Synechococcus sp., comprised both large (57,000 dalton) and small (12,000 dalton) subunits. The undissociated, purified enzyme was considerably smaller than the spinach enzyme when compared by pore-gradient electrophoresis, gel filtration and density-gradient centrifugation. This suggested that the cyanobacterial enzyme might have a hexameric (L6S6) subunit structure, unlike the enzymes from spinach and many other organisms which are octamers (L8S8). However, the molecular weight of the Synechococcus enzyme was measured by equilibrium sedimentation and found to be 530,000, which is within the range observed for L8S8-type enzymes. Furthermore, electron microscopic studies of negatively stained preparations of both the native enzyme, and a preparation depleted of 87% of its small subunits by repeated mild-acid precipitation, revealed four-fold symmetry characteristic of an octameric, cubical structure. Synechococcus RuP2 carboxylase therefore must be an L8S8 octamer and its anomalous pore-penetration behaviour may be due to an asymmetric shape. Some support for the latter possibility was provided by electron miscoscopic observations of two different types of images which may be different views of the molecule in two planes.
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  • 34
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    Archives of microbiology 141 (1985), S. 85-90 
    ISSN: 1432-072X
    Keywords: C. sporosphaeroides ; Citrate lyase ; Regulation ; Purification ; Properties ; Electron microscopy
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    Topics: Biology
    Notes: Abstract Cells of Clostridium sporosphaeroides which were grown on citrate contained citrate lyase and citrate lyase acetylating enzyme, but no detectable citrate synthase and citrate lyase deacetylase activities. Citrate lyase from C. sporosphaeroides was purified to homogeneity as judged by polyacrylamide gel electrophoresis and high performance liquid chromatography. In contrast to the enzyme from Clostridium sphenoides, the addition of l-glutamate was not necessary for activity and stabilization of the enzyme. The purified enzyme had a specific activity of 34 U/mg protein and was comparable to other citrate lyases with respect to its molecular weight and subunit composition. Electron microscopic investigations showed that similar to the lyase from C. sphenoides and in contrast to all other citrate lyases examined so far, the majority of the enzyme molecules was present in “star” form.
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  • 35
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    Archives of microbiology 142 (1985), S. 259-261 
    ISSN: 1432-072X
    Keywords: Methanogenic bacteria ; Plasmid isolation ; Alkaline lysis ; CsCl gradient ; Restriction endonuclease mapping ; Electron microscopy ; DNA homology
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    Topics: Biology
    Notes: Abstract Of 21 recently isolated strains of methanococci, one was found to harbor a small, cryptic, low copy number plasmid. Reproducible recovery was achieved by alkaline lysis of cells pretreated with proteinase K in an osmotically stabilizing buffer. The plasmid was found to contain a singleAval site. No homology was detected between the plasmid and DNA from any of the other new strains or from five known species of methanococci.
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  • 36
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    Archives of microbiology 143 (1986), S. 400-402 
    ISSN: 1432-072X
    Keywords: E. coli relA +/relA ; Starvation survival ; Guanosine tetraphosphate ; Electron microscopy ; Glycogen
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    Notes: Abstract Amino acid-starved cells of Escherichia coli relA +, which contain a large number of glycogen particles, are able to survive in phosphate buffer for a longer time period than their relaxed counterparts. With regard to NH 4 + starvation differences in the survival of both strains were not found. NH 4 + starved cells of E. coli relA are able to synthesize glycogen but amino acid-starved cells of the relA strain are not. We suggest that the synthesis of glycogen triggered by guanosine tetraphosphate during amino acid starvation is responsible for the prolonged viability of the E. coli relA + strain.
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  • 37
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    Archives of microbiology 146 (1986), S. 267-274 
    ISSN: 1432-072X
    Keywords: Photosynthesis ; Membrane structure ; Electron microscopy ; Ectothiorhodospira ; Serial thin sectioning ; Three dimensional reconstruction
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    Notes: Abstract The three dimensional organization of the complete photosynthetic apparatus of the extremely halophilic, bacteriochlorophyll b containing Ectothiorhodospira halochloris has been elaborated by several techniques of electron microscopy. Essentially all thylakoidal sacs are disc shaped and connected to the cytoplasmic membrane by small membraneous “bridges”. In sum, the lumina of all thylakoids (intrathylakoidal space) form one common periplasmic space. Thin sections confirm a paracrystalline arrangement of the photosynthetic complexes in situ. The ontogenic development of the photosynthetic apparatus is discussed based on a structural model derived from serial thin sections.
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  • 38
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    Keywords: Thiobacillus ferrooxidans ; Sulfur production ; Sulfur oxidation ; Inhibitors ; Uncouplers ; Electron microscopy
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    Notes: Abstract The intermediary production of elemental sulfur during the microbial oxidation of reduced sulfur compounds has frequently been reported. Thiobacillus ferrooxidans, an acidophilic chemolithoautotroph, was found to produce an insoluble sulfur compound, primarily elemental sulfur, during the oxidation of thiosulfate, trithionate, tetrathionate and sulfide. This was confirmed by light and electron microscopy. Sulfur was produced from sulfide by an oxidative step, while the production from tetrathionate was initiated by a hydrolytic step, probably followed by a series of chemical reactions. The oxidation of intermediary sulfur was severely inhibited by sulfhydryl-binding reagents such as N-ethylmaleimide, by the addition of uncouplers or after freezing and thawing of the cells, which probably damaged the cell membrane. The mechanisms behind these inhibitions have not yet been clarified. Finally, it was observed that elemental sulfur oxidation by whole cells depended on the medium composition. The absence of sulfate or selenate reduced the sulfur oxidation rate.
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  • 39
    ISSN: 1432-0983
    Keywords: Sugar beet ; Cytoplasmic male sterility ; Mitochondrial DNA ; Electron microscopy
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    Topics: Biology
    Notes: Summary Mitochondrial (mt) DNAs from normal (N) and male sterile (S) cytoplasms of sugar been have been isolated and investigated by electron microscopy. The results showed that mtDNA was composed of a heterogeneous population of circular molecules. Their contour lengths varied from 0.28 to 51 μm, but unlike in the case of maize, a large difference was not observed in the distribution of molecular classes greater than 1.0 μm between N and S cytoplasms of sugar beet. On the other hand, N and S cytoplasms were shown to contain their own characteristic combinations of small circular mtDNA species with lengths between 0.28 μm and 0.6 μm. Mitochondrial DNAs from various sources of male-sterile cytoplasms were analyzed by agarose gel electrophoresis to determine the extent of cytoplasmic variation. Additional low molecular weight DNA bands appeared in all male-sterile lines examined, and as a result, three distinctive banding patterns were recognized. These data are in general agreement with those based upon restriction endonuclease digestion of mt and chloroplast DNAs and the genetic analysis of fertility restoration in test crosses.
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  • 40
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    European biophysics journal 7 (1981), S. 209-212 
    ISSN: 1432-1017
    Keywords: Photosynthetic bacteria ; Electron microscopy ; Planar lattices
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    Topics: Biology , Physics
    Notes: Abstract The thylakoids of Rhodopseudomonas viridis have been studied by freeze-fracturing whole cells. Depending on growth conditions and treatment before freezing, three different types of particle arrangements in the photosynthetic membrane are reported: a random arrangement, an isometric (quadratic) lattice arrangement with a lattice constant of 12.5 ± 0.8 nm, and a hexagonal lattice arrangement with a lattice constant of 12.5 ± 0.8 nm.
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  • 41
    ISSN: 1432-0983
    Keywords: Electron microscopy ; Replicative intermediates
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    Notes: Summary Some physicochemical properties of the mitochondrial DNAs (mtDNA) from plants of flax, broad bean and mung bean, and from tissue culture cells of jimson weed, soybean, petunia and tobacco were determined. Circular molecules were observed in electron microscope preparations of each mtDNA. In soybean, petunia, broad bean and mung bean mtDNAs, the circular molecules had a continuous distribution of lengths (ranges between 1 to 36 kb, and 1 to 126 kb), heavily skewed toward smaller molecules. Eighty-six percent of the flax circular molecules were from 27 to 54 kb in size, and 78% of the jimson weed circular molecules were from 4 to 15 kb. Replicative forms of 1.2–1.6 kb circular molecules were observed in electron microscope preparations of broad bean mtDNA.
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  • 42
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    Current genetics 14 (1988), S. 163-170 
    ISSN: 1432-0983
    Keywords: Plant mtDNA ; Electron microscopy ; Restriction enzymes ; Hairpin structures
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    Notes: Summary Broad bean (Vicia faba) mitochondrial DNA (mtDNA) includes three circular plasmids: mt-plasmid 1 (1,704 ntp), mt-plasmid 2 (1,695 ntp) and mt-plasmid 3 (1,476 ntp). Partially replicated circular forms of these mt-plasmids have been observed in electron microscope preparations. Restriction enzymes that cleave either mt-plasmid 2 (but not mt-plasmids 1 and 3) or mt-plasmid 3 (but not mt-plasmids 1 and 2) were used to generate linear forms of partially replicated mt-plasmid 2 and mt-plasmid 3 molecules. Analyses of these linearized replicative intermediates, observed by electron microscopy, indicated that in both mt-plasmid 2 and mt-plasmid 3 replication originates at a specific location and proceeds in the same, single direction around the molecules. The replication origins of mt-plasmid 2 and mt-plasmid 3 map close to sequences that can fold into hairpin structures.
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  • 43
    ISSN: 1432-0983
    Keywords: Allomyces macrogynus ; Mitochondrial DNA ; Electron microscopy ; Restriction enzyme map
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    Notes: Summary The mitochondrial (mt) DNA of the aquatic phycomycete Allomyces macrogynus is a circular molecule with a size of 56.1 kbp. The cleavage sites for the restriction enzymes SalI and PvuI were mapped by comparing the partial denaturation patterns of isolated restriction fragments with the pattern of the intact circle. The genes coding for the small and large ribosomal RNA (rRNA) were located on the restriction map by heteroduplex and R-loop analysis. The gene coding for the large rRNA contains an intervening sequence, app. 0.7 kbp in size, near the 3′-end of the gene. The two rRNA genes are encoded on the same strand of the mtDNA and separated by a region of 17–18 kbp. This rRNA gene organization is similar to that found with members of the Ascomycetes.
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  • 44
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    Archives of microbiology 128 (1980), S. 12-18 
    ISSN: 1432-072X
    Keywords: Moraxella glucidolytica ; Electron microscopy ; Lipopolysaccharide
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    Notes: Abstract A cellular (LPS I) and extracellular (LPS II) lipopolysaccharide were isolated from Moraxella glucidolytica cells grown on ethanol and from the culture fluid, respectively. Both LPS were toxic when injected to mice and chick embryos. These LPS contained glucose, galactose, glucosamine, galactosamine, 2-keto-3-deoxyoctonate and lipids. By permethylation studies, glucose was found to be linked (1→6) and (1→3) in LPS I and only (1→6) in LPS II. Galactose was the terminal non-reducing sugar. Branching occurred at positions 3 and 4 of galactose residues. LPS I was rich in α- and β-hydroxylauric and α-hydroxymyristic acids and LPS II contained mainly stearic and α-hydroxymyristic acids. LPS I was detoxified by mild acid and alkaline treatments. It was also dissociated by sodium deoxycholate and chromatographed on Sephadex G-75. The main fraction was reassociated by removing the surfactant by dialysis. The morphology of LPS I and LPS II was examined by electron microscopy. LPS I (original and reassociated fractions) consisted exclusively of ribbons while LPS II contained ribbons and vesicles.
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  • 45
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    Archives of microbiology 135 (1983), S. 25-29 
    ISSN: 1432-072X
    Keywords: Electron microscopy ; Euglena mutabilis ; Flagellate ; Photomovement ; Photoreceptor ; Phototaxis ; Single-cell analysis ; Videomicroscopy
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    Topics: Biology
    Notes: Abstract Due to the lack of an emergent flagellum the green flagellate Euglena mutabilis is restricted to gliding motility. During forward movement, the organisms orient positive phototactically in the presence of a suitable light stimulus. The cell contains both a stigma and a paraflagellar body which differ in shape and size from the organelles found in E. gracilis. The degree of orientation in white light follows an optimum curve with a maximum at about 100 lx. The spectral sensitivity shows a number of prominent peaks in the blue and green regions and extends well into the red region of the visible spectrum. Since the cell does not rotate during locomotion a periodic shading mechanism cannot account for phototactic orientation. Thus, phototaxis in the related species, E. gracilis and E. mutabilis differ in their photoreceptor molecules, their sensory transduction chains and their strategies of light direction detection.
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  • 46
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    Archives of microbiology 130 (1981), S. 125-128 
    ISSN: 1432-072X
    Keywords: Rhodospirillum rubrum ; Chromatophores ; Reaction centers ; Liposomes ; Electron microscopy
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    Topics: Biology
    Notes: Abstract In freeze-fractures of chromatophores of Rhodospirillum rubrum the reaction centers are seen as hexagonal arranged particles of 13 nm diameter with a density of around 5,500 particles per μm2. Similar regions on the cytoplasmic membrane suggest that these parts are the prospective invagination sites. Isolated reaction centers are easily incorporated into liposomes. In freeze fractures of liposomes particles similar in shape and size, although less dense as in chromatophores are observed. In negative staining much smaller units of only 5 nm in diameter are found indicating that reaction centers occur in the membrane as tri- or tetramers. There is a strong correlation between particle density in chromatophores and titratable reaction centers remaining in these membranes after extraction of reaction centers by detergents; both values are in good agreement with the yield of reaction centers at a given detergent concentration.
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  • 47
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    Archives of microbiology 138 (1984), S. 273-277 
    ISSN: 1432-072X
    Keywords: Cyanobacteria ; Secondary metabolite ; Allelopathy ; Photosynthesis ; Electron transport ; Thylakoids ; Herbicides ; Electron microscopy
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    Notes: Abstract Cyanobacterin is a secondary metabolite produced by the cyanobacterium, Scytonema hofmanni. Highly purified cyanobacterin was found to inhibit the growth of many cyanobacteria at a minimum effective dose of 2 μg/ml (4.6 μM). The antibiotic had no effect on eubacteria including the photosynthetic Rhodospirillum rubrum. The site of action of cyanobacterin was further investigated in the unicellular cyanobacterium, Synechococcus sp. Electron micrographs of antibiotic-treated Synechococcus cells indicated that cyanobacterin affects thylakoid membrane structure. The antibiotic also inhibited light-dependent oxygen evolution in Synechococcus cells and in spheroplasts. These data support our conclusion that cyanobacterin specifically inhibits photosynthetic electron transport. This activity is similar to herbicides such as 3-(3,4-dichlorophenyl)-1,1-dimethyl urea (DCMU). The anhydro analog of cyanobacterin had no biological activity.
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  • 48
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    Archives of microbiology 140 (1984), S. 265-270 
    ISSN: 1432-072X
    Keywords: EcoRI ; EcoRI-DNA complexes ; EcoRI* activity ; Recognition sites ; Frequency of binding ; Electron microscopy
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    Notes: Abstract Electron microscopy of negatively stained isolated restriction enzyme EcoRI revealed particle projections with triangular or square outlines, indicating that the enzyme, in its tetrameric state, is tetrahedron-like. The two dimers making up the tetramer appear to be arranged in two planes orthogonal to each other. Complexes formed by EcoRI with the plasmids pBR322 or pGW10 were investigated by electron microscopic spreading techniques. In the presence of Mg2+, EcoRI was bound to the DNA molecules to form pearl necklace-like aggregates. The number of bound EcoRI particles was much higher as the sum of EcoRI-and 5′..AATT..3′ sites (with exceptions, the 5′..AATT..3′ sites may function as one type of EcoRI* sites) along the DNAs, indicating unspecific binding. In the absence of Mg2+, EcoRI was bound to the DNA only at the recognition site for EcoRI and the sites where the tetranucleotide sequence 5′..AATT..3′ was present. A direct correlation of the local concentrations of the bases A and T within the flanking sequences of the binding sites with the frequency of EcoRI to the DNA was observed. Dimers and tetramers of the enzyme was found to bind to the DNA. Tetramers occasionally exhibited two binding sites for DNA as indicated by the observation of DNA loops originating at the sites of bound tetrameric EcoRI particles.
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  • 49
    ISSN: 1432-072X
    Keywords: Bradyrhizobium ; Electron microscopy ; Mutants ; Nitrogen fixation ; Nodulation ; Soybean ; Symbiosis ; Transposon Tn5
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    Notes: Abstract The genome of the slow-growing Bradyrhizobium japonicum (strain 110) was mutagenized with transposon Tn5. A total of 1623 kanamycin/streptomycin resistant derivatives were screened in soybean infection tests for nodulation (Nod) and symbiotic nitrogen fixation (Fix). In this report we describe 14 strains possessing a stable, reproducible Nod+Fix- phenotype. These strains were also grown under microaerobic culture conditions to test them for free-living nitrogen fixation activity (Nif). In addition to strains having reduced Fix and Nif activities, there were also strains that had reduced symbiotic Fix activity but were Nif+ ex planta. Analysis of the genomic structure revealed that the majority of the strains had a single Tn5 insertion without any further apparent physical alteration. A few strains had additional insertions (by Tn5 or IS50), or a deletion, or had cointegrated part of the vector used for Tn5 mutagenesis. One of the insertions was found in a known nif gene (nifD) whereas all other mutations seem to affect different, hitherto unknown genes or operons. Several mutant strains had an altered nodulation phenotype, inducing numerous, small, widely distributed nodules. Light and electron microscopy revealed that most of these mutants were defective in different stages of bacteroid development and/or bacteroid persistence. The protein patterns of the mutants were inspected by two-dimensional gel electrophoresis after labelling microaerobic cultures with l-(35S)methionine. Of particular interest were mutants lacking a group of proteins the synthesis of which was known to be under oxygen control. Such strains can be regarded as potential regulatory mutants.
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  • 50
    ISSN: 1432-072X
    Keywords: Acidaminococcus fermentans ; Glutamate fermentation ; Electron microscopy ; Immunocytochemistry ; Post-embedding labelling ; Antibody-gold complexes ; Protein A-gold complexes
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    Notes: Abstract We have investigated the in situ location of glutaconyl-CoA decarboxylase and 2-htdroxyglutaryl-CoA dehydratase in Acidaminococcus fermentans using the antibody-gold and protein A-gold techniques carried out as a post-embedding immunoelectron microscopic procedure. Polyclonal antisera were raised in rabbits against homogeneous fractions of the enzymes. Anaerobically grown cells of A. fermentans of the late exponential growth phase were fixed with 0.2% glutaraldehyde and 0.3% formaldehyde (final concentrations) in the growth medium. Dehydration of the cells was achieved with methanol. The cells were embedded in the low temperature embedding resin Lowicryl K4M. The markers indicative for antigenic sites of the two enzymes unequivocally demonstrate that the sodium pump glutaconyl-CoA decarboxylase is located at the cell periphery being a membrane-bound enzyme as expected whereas 2-hydroxyglutaryl-CoA dehydratase is a soluble cytoplasmic enzyme.
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  • 51
    ISSN: 1432-072X
    Keywords: Biological control ; Cyanobacteria ; Electron microscopy ; Entrapment ; lysis ; Myxococcus ; Phormidium ; Spherule
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    Notes: Abstract A Myxococcus xanthus isolate from a farm drainage ditch, designated strain PCO2, is capable of rapidly inducing lysis of both agar and liquid-grown cultures of the cyanobacterium, Phormidium luridum, var. olivacea. Microscopic studies of the predator-prey interaction demonstrate that lysis of the cyanobacterium occurs within clumps and spherules formed by the cells of M. xanthus PCO2. In the earliest stage, one sees the formation of irregular microclumps of bacteria and cyanobacterial filaments. As these clumps mature, colonies 1 to 6 mm in diameter develops. The center of these densely green colonies contains cyanohacteria in various stages of degradation, while the periphery is almost exclusively a tightly woven mass of myxobacterial cells. Electron microscopy shows that long extrusions from the outer membrane of the M. xanthus PCO2 cells are involved in the formation both of initial clumps and of mature colonial spherules. These extrusions appear to efficiently entangle the cyanobacterial filaments in the culture environment. Predator-to-prey ratios of 1/10, 1/100 and 1/1,000 have resulted in cyanobacterial lysis. Because the entrapment and lysis of P. luridum filaments by M. xanthus PCO2 appears to be independent of any other heterotrophic nutritional requirement, as well as of environmental agitation, this system has potential as a biological control technique for undesirable aquatic cyanobacteria.
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  • 52
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    Archives of microbiology 140 (1985), S. 338-342 
    ISSN: 1432-072X
    Keywords: Sporosarcina halophila ; Endospores ; Electron microscopy ; Heat resistance ; Ethanol resistance ; Germination ; Dipicolinic acid
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    Notes: Abstract Sporosarcina halophila forms endospores. Electron micrographs revealed ultrastructural similarity to spores of S. ureae. Spore germination indicated by loss of refractility, darkening, swelling and formation of new vegetative cells was followed by phase contrast light microscopy. To induce spore germination, the endospores needed to be heat avtivated. After activation, they were inoculated into nutrient broth medium supplemented with sea-water. Double concentrated sea-water was found to be optimal for germination. Similar to other bacterial endospores, the spores were found to be resistant to heat and ethanol. An ultraviolet absorbing substance was isolated from suspensions of free spores; it was identified to be pyridine-2,6-dicarboxylic acid (DPA) usually present in bacterial spores. DPA was detected in amounts ranging from 5–7% of the spore dry weight; it was not detected in extracts of vegetative cells.
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  • 53
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    Archives of microbiology 132 (1982), S. 10-13 
    ISSN: 1432-072X
    Keywords: Calcofluor White ; Cell wall structure ; Chlorella ; Electron microscopy ; Protoplast ; Ruthenium Red
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Among 12 strains ofChlorella ellipsoidea, C. vulgaris, andC. saccharophila tested, 4 strains (1,C. ellpsoidea; 2,C. vulgaris; 1,C. saccharophila) formed osmotically labile protoplasts after treatment with mixtures of polysaccharide degrading enzymes. The relationship between enzymatical digestibility and structure or composition ofChlorella cell walls were studied by electron microscopy and staining techniques with some specific dyes. The cell wall structures of the 12Chlorella strains were grouped into three types: (1) with a trilaminar outer layer, (2) with a thin outer monolayer, and (3) without an outer layer. Protoplasts were formed only from the strains with a cell wall of Type 2. In the strains with a cell wall of Type 1, the outer layer protected the inner major microfibrillar layer against enzymatic digestion. The cell wall of Type 3 was totally resistant to the enzymes; the chemical composition of the cell wall would be somewhat different from that of other types.
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  • 54
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    Archives of microbiology 135 (1983), S. 169-175 
    ISSN: 1432-072X
    Keywords: Photosynthetic membranes ; Electron microscopy ; Image processing ; Ectothiorhodospira halochloris ; Ectothiorhodospira abdelmalekii ; Rhodopseudomonas viridis ; Rhodopseudomonas sulfoviridis ; Thiocapsa pfennigii
    Source: Springer Online Journal Archives 1860-2000
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    Notes: Abstract The photosynthetic membranes of the five bchl b-containing bacteria Ectothiorhodospira halochloris, E. abdelmalekii, Rhodopseudomonas viridis, R. sulfoviridis and Thiocapsa pfennigii have been investigated by electron microscopy and digital image analysis. All five species have the photosynthetic complexes hexagonally arrayed in the membrane with lattice spacings close to 13 nm, except for R. sulfoviridis and T. pfennigii which display somewhat smaller (∼12.5 nm) lattice spacings. Correlation averaging which imposes less stringent requirements on the lattice perfection than conventional Fourier filtration techniques has been employed to elucidate the structure of the photosynthetic complexes. Their basic organization, i.e. a ring, probably containing the light-harvesting (LH) polypeptides, surrounding a core (the “reaction centre”) appears to be almost identical for all species under scrutiny. Despite a resolution of ∼1.6 nm, however, little further significant substructure can be deduced from the averages; possible reasons for the “blurred” appearance of the LH-ring and absence of any subdivision in the reaction centre are discussed along with strategies aimed at obtaining a more detailed model of the molecular architecture of the photosynthetic membranes.
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  • 55
    ISSN: 1432-072X
    Keywords: Aggregation substance ; Enterococcus faecalis ; Electron microscopy ; Field emission scanning electron microscopy ; Immunogold labelling technique ; Sex pheromone system
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The distribution of sex pheromone induced aggregation substance was studied on the cell surface of various Enterococcus faecalis strains. In the accompanying paper we have shown that the aggregation substance appears as a layer of hairlike structures. Using direct and indirect immunogold technique, transmission electron microscopy and high resolution scanning electron microscopy we investigated the appearance and distribution of the aggregation substance. The “hairs” increase in number with increasing exposure to sex pheromones (maximum density: 1300/μm2). We show that these structures are unequally distributed over the cell surface, even if the cells were induced by sex pheromones for a long period of time. Statistical analysis of the unequal distribution indicates that aggregation substance is incorporated into pre-existing “old” cell-walls and that this incorporation shows a saturation ca. 40 min after addition of sex pheromones.
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  • 56
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    Archives of microbiology 126 (1980), S. 87-95 
    ISSN: 1432-072X
    Keywords: Ascodichaena ; Beech bark ; Electron microscopy ; Host-fungus relationship
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    Topics: Biology
    Notes: Abstract Ascodichaena rugosa Butin is a corkinhabiting fungus, found frequently on the bark of Fagus sylvatica L. The hyphae of the fungus are distributed solely in the phellem cells, stopping their growth in the last-formed cork cell layer. The cell to cell invasion is effected by penetration hyphae, causing no extensive dissolution of the cork wall. Electron microscopical observations revealed fine structural details of the fruit bodies and of the intracellular hyphae. Of special interest were the finger-like hyaline hyphae in the last-formed layer of cork cells, which are interpreted as haustoria on the basis of the fine structure both of hyphae and host cells. This situation is considered as reflecting a parasitic relationship of Ascodichaena to beech bark. The activity of the fungus led also to the increased production of cork cells, perhaps related to the nutrient supply of the fungus.
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  • 57
    ISSN: 1432-072X
    Keywords: Immunoferritin labeling ; Electron microscopy ; Membrane vesicles ; Nitrate reductase ; Bacillus licheniformis ; Klebsiella aerogenes
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    Topics: Biology
    Notes: Abstract The indirect immunoferritin labeling method was used to localize the membrane-bound respiratory nitrate reductase in membrane vesicles and protoplasts or spheroplasts of Bacillus licheniformis and Klebsiella aerogenes, respectively. For a comparison of the labeling of the various vesicle preparations, which differed not only in size but also in the percentage of inside-out orientation, a quantification of the results was needed to circumvent the problem of non-specifically bound ferritin. From the results the sidedness of the nitrate reductase in the cytoplasmic membrane of the abovementioned bacteria was determined as being cytoplasmic in B. licheniformis and as transmembranous in K. aerogenes.
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  • 58
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    Archives of microbiology 131 (1982), S. 116-123 
    ISSN: 1432-072X
    Keywords: Cell wall ; Wall degradation ; Lysozyme ; Autolysines ; Electron microscopy ; Staphylococcus aureus
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    Topics: Biology
    Notes: Abstract In contrast to former findings lysozyme was able to attack the cell walls ofStaphylococcus aureus under acid conditions. However, experiments with14C-labelled cell walls and ribonuclease indicated that, under these conditions, lysozyme acted less as an muralytic enzyme but more as an activator of pre-existing autolytic wall enzymes. Electron microscopic studies showed that under these acid conditions the cell walls were degraded by a new mechanism (i.e. “attack from the inside”). This attack on the cell wall started asymmetrically within the region of the cross wall and induced the formation of periodically arranged lytic sites between the cytoplasmic membrane and the cell wall proper. Subsequently, a gap between the cell wall and the cytoplasmic membrane resulted and large cell wall segments became detached and suspended in the medium. The sequence of lytic events corresponded to processes known to take place during wall regeneration and wall formation. In the final stage of lysozyme action at pH 5 no cell debris but “stabilized protoplasts” were to be seen without detectable alterations of the primary shape of the cells. At the same time long extended ribbon-like structures appeared outside the bacteria. The origin as well as the chemical nature of this material is discussed. Furthermore, immunological implications are considered.
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  • 59
    ISSN: 1432-072X
    Keywords: Bacteriolysis ; Penicillin ; Autolysis ; Cell wall ; Electron microscopy ; Staphylococcus aureus
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    Notes: Abstract The actual reason for the penicillin-induced bacteriolysis of staphylococci was shown to be the “punching” of one or a few minute holes into the peripheral cell wall at predictable sites. These perforations were the result of the lytic activity of novel, extraplasmatic vesicular structures, located exclusively within the bacterial wall material, which we have named “murosomes”. In untreated staphylococci the punching of holes into the peripheral wall is a normal process which follows cross wall completion and represents the first visible step of cell separation. Under penicillin, however, analogous holes are punched by the murosomes at sites of presumptive cell separation even if no sufficient cross wall material had been assembled before at this site (but had rather been deposited at other sites). Consequently, because of the internal pressure of the protoplast, lytic death is the inevitable result of this perforation of the protective peripheral wall. Hence, the real mechanism of penicillin-induced bacteriolysis in staphylococci is considered to be mainly the result of a special morphogenetic wall defect: bacteriolysis is taking place regularly when a cell separation process is no longer preceeded by sufficient cross wall assembly at the correct place. However, hypotheses which are based purely on some variations of overall biochemical processes like total wall enzyme activities or total wall synthesis are not regarded to be sufficient to explain this type of lytic death.
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    Archives of microbiology 142 (1985), S. 333-339 
    ISSN: 1432-072X
    Keywords: Photosynthesis ; Membrane structure ; Electron microscopy ; Photosynthetic bacteria
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    Topics: Biology
    Notes: Abstract The organization of photosynthetic membranes in the cytoplasm of the photosynthetic bacterium Rh. viridis has been examined by several techniques for electron microscopy. Thin sections of membrane stacks show that the regular lattice of membrane subunits reported in other studies can be observed in thin section. Tilting of sections in the electron microscope shows that the regular lattices of several membranes overlap in a way that suggests they are in register with each other. This observation can be confirmed by freeze-fracture images in which a regular arrangement of membrane lattices can be observed, each perfectly aligned. Analysis of the spacings of membrane pairs shows that the photosynthetic membranes of Rh. viridis are very closely apposed. The mean diameter of two membranes is 160A, and the average space between two such membranes is only 42A. When a recently developed atomic level model of Rh. viridis reaction center is superimposed against these spacings, each reaction center extends from the surface of its respective membrane far enough to make contact with an apposing membrane. The limited free space between membranes and regular alignment of lattices has a number of implications for how this membrane is organized to carry out the process of energy transfer.
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  • 61
    ISSN: 1432-2242
    Keywords: Plant mitochondrial genome ; Minicircle DNA ; Electron microscopy ; Beta vulgaris L.
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    Topics: Biology
    Notes: Summary The structure of mitochondrial DNA (mt-DNA) from sugarbeet (Beta vulgaris L.) has been studied by biochemical methods and electron microscopy. It was found to be complex multipartite consisting of two main classes of molecules: high molecules weight (HMW) mtDNA and low molecular weight (LMW) mtDNA. The HMW mtDNA consists of rosette-like structures and globules resembling chromomeres (150–200nm). A typical rosette has a protein core and radially stemming closed DNA loops (from 0.6-1.5 μm). The number of loops in a rosette varies from 16–30. The bulk of HMW mtDNAs are represented by interconnected rosettes (total contour length about 130–160 μm, 403–496 kbp). Such large circular DNAs may be evidence of the master chromosome arrangement of the sugarbeet genome. Globules and rosettes are interconnected by thick and thin DNA fibrils, along which nucleosome- and nucleomere-like structures are distributed. The LWM mtDNA is composed of two groups of supercoiled circular molecules, 0,2–1.5 μm and 0.02–0.05 μm in size. Electrophoretic analysis demonstrated that LWM mtDNA is represented by minicircle plasmid-like DNA molecules of 1.3, 1.4 and 1.6 kbp.
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  • 62
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    Entomologia experimentalis et applicata 34 (1983), S. 20-26 
    ISSN: 1570-7458
    Keywords: Dioryctria abietella ; Cone pyralid ; Lepidoptera ; Pyralidae ; Sex pheromone, (Z,E)-9,11-tetradecadienyl acetate ; Single sensillum recordings ; Electroantennography ; Gas chromatography ; Mass spectrometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé L'analyse en chromatographie gazeuse associée à une détection électroantennographique a montré que l'acétate (Z,E)-9,11-tétradécadiényle (Z,E)-9,11–14:Ac est l'un des composants de la phéromone de Dioryctria abietella Schiff (Lepid.: Pyralidae). Couplage chromatographie en phase gazeuse spectrometrie de masse a montré la présence d'acétate tétradécadiényle avec un spectre de masse et un indice de rétention identiques au Z,E-9,11–14:Ac Un récepteur cellulaire sensible à la fois au Z,E-9,11–14:Ac et à un extrait de la femelle a été identifié sous l'antenne du mâle. Les analyses des antennogrammes et de la cellule isolée ont étayé la caractérisation du composant de la phéromone comme étant Z,E-9,11–14:Ac. Un récepteur cellulaire additionnel sensible à l'acétate (Z.)-9-tétradécadiényle et à l'acétate (Z.E.)-9,12-tétradécadiényle a été trouvé sur l'antenne du mâle, mais il n'était pas activé par l'extrait de la femelle. Sur le terrain Z,E-9,11–14:Ac, présenté seul, attirait des nombres importants de mâles de D. abietella. L'addition de l'acétate (Z)-9-tétradécényle a inhibé l'attraction des mâles par les pièges.
    Notes: Summary Gas chromatographic analyses coupled with electro-antennographic detection indicated that (Z,E)-9,11-tetradecadienyl acetate (Z,E-9, 11–14:Ac) is a pheromone component of the cone pyralid Dioryctria abietella. Gas chromatographic-mass spectrometric analyses confirmed the presence of a tetradecadienyl acetate with mass spectrum and retention index identical to Z,E-9,11–14:Ac. A receptor cell sensitive to both Z,E-9,11–14:Ac and the female extract was identified on the male antenna. An additional receptor cell sensitive to (Z)-9-tetradecenyl acetate and (Z,E)-9,12-tetradecadienyl acetate was found on the male antenna but was not activated by the female extract. In the field Z,E-9,11–14:Ac presented alone attracted significant numbers of male D. abietella. Addition of (Z)-9-tetradecenyl acetate inhibited the attraction of males to traps.
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  • 63
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    Entomologia experimentalis et applicata 34 (1983), S. 174-178 
    ISSN: 1570-7458
    Keywords: Lepidoptera ; Pyralidae ; Maruca testulalis ; Pod borer ; Development ; Nutritional suitability ; Host plant ; Crotalaria ; Vigna unguiculata
    Source: Springer Online Journal Archives 1860-2000
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    Description / Table of Contents: Résumé Les possibilités de développement larvaire de Maruca testulalis sur les fleurs de huit espèces végétales ont été examinées en laboratoire. La comparaison a porté sur Crotalaria retusa, C. juncea, C. saltiana, C. misereniensis, C. mucronata, C. amazonas, Cajanus cajan et l'hôte principal de cette chenille, Vigna unguiculata. En tenant compte de la mortalité larvaire et des indices de croissance (G.I.), ces plantes ont été divisées en trois catégories principales: 1 celles provoquant une mortalité larvaire de 0–30% et ayant des G.I. ≥60%, constituent les plantes hôtes convenables (Vigna unguiculata seule); 2 les plantes qui provoquent une mortalité larvaire de 30≤50% et ont des G.I. de 30 à 60% de la plante hôte principale (Cajanus cajan, Crotalaria amazonas, C. saltiana, C. mucronata; 3 les plantes qui causent 50–100% de mortalité larvaire et dont les G.I. sont inférieurs à 30% de la plante hôte principale (Crotalaria retusa, C. juncea, C. misereniensis). Les résultats déjà publiés sur les choix du lieu de ponte des femelles et l'utilisation de C. juncea comme plante piège, sont discutés à la lumière de ces données nouvelles.
    Notes: Abstract Flowers of eight plant species were evaluated under laboratory conditions for their suitability as larval growth media for the cowpea pod borer, Maruca testulalis. The plants tested were Crotalaria retusa, C. juncea, C. saltiana, C. misereniensis, C. amazonas, Cajanus cajan and the principal host of the borer, Vigna unguiculata (cowpea), was included for comparison. Based on the data obtained on larval mortality and growth indices (GI) the plants were divided into 3 categories namely: I: Those causing 0–30% mortality and having GI value ≥60% form suitable host plants. This group only included V. unguiculata. — II: Those plant species causing 30≤50% larval mortality and having GI value 30%≤60% of the principal host plant (Cajanus cajan, Crotalaria amazonas, C. saltiana, C. mucronata). This group of species is marginally suitable as hosts. — III: Plants causing 50–100% larval mortality and having GI value ≤30% of principal host plant (C. retusa, C. juncea and C. misereniensis). Previously published data on the oviposition preference of the adult moth are discussed in the light of the present findings and the use of C. juncea as a possible trap crop.
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  • 64
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    Entomologia experimentalis et applicata 30 (1981), S. 106-110 
    ISSN: 1570-7458
    Keywords: assimilation efficiency ; growth efficiency ; niche breadth ; specialization ; hostplant relations ; plant-insect interactions ; Malacosoma americanum ; Malacosoma disstria ; Lasiocampidae ; Lepidoptera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Raupen von Malacosoma americanum, einer oligophagen Art, die sich vor allem auf Prunus und andern baumartigen Rosaceen. entwickelt, wurden mit Raupen der polyphageren Verwandten M. disstria in Hinblick auf die Verwertung der Blätter ihres gemeinsames Wirtes Prunus serotina verglichen. Wirerhielten ähnliche Werte wie sie früher für andere Lepidopteren publiziert worden waren und zwar in Bezug auf die üblichen Messwerte, Anteil verwertete Nahrung, Wachstum in Trockengewicht pro Einheit gefressene oder verwertete Nahrung. Zudem unterschieden sich die beiden Arten in keiner Masszahl für Effizienz. Unsere Resultate sind im Einklang mit der Folgerung, das spezialisierte phytophage Insekten ihre Wirtspflanzen nicht besser ausnützen als as polyphage Arten tun.
    Notes: Abstract Larvae of Malacosoma americanum (F.) an oligophagous species that feeds primarily on Prunus and other rosaceous trees, were compared to larvae of the more highly polyphagous congener M. disstria Hb., with respect to the efficiency of utilization of the foliage of a common host plant, Prunus serotina Ehrh. We obtained values similar to those reported for other Lepidoptera for the commonly used measures of the fraction of ingested food that was assimilated, and for the growth in dry weight per unit of food ingested or assimilated. Moreover, the two species did not differ in any measure of efficiency. Our results are compatible with the conclusion that specialized phytophagous insects do not use their host plants with greater physiological efficiency than do generalized insects.
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  • 65
    ISSN: 1570-7458
    Keywords: Adoxophyes orana ; inhibition ; Lepidoptera ; male pheromone ; myristic acid ; palmitic acid ; summerfruit tortrix ; Tortricidae
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  • 66
    ISSN: 1570-7458
    Keywords: Grapholita lobarzewskii ; Grapholita janthinana ; (Z)-8-dodecenyl acetate ; (E)-8-dodecenyl acetate ; sex pheromone ; Lepidoptera ; Tortricidae
    Source: Springer Online Journal Archives 1860-2000
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    Description / Table of Contents: Zusammenfassung Chemische Analysen und Feldversuche zeigen, dass das Sexualpheromon des Kleinen Fruchtwicklers, G. lobarzewskii aus (E)-8-Dodecenylacetat (Z8-12:Ac) und (Z)-8-Dodecenylacetat (Z8-12:Ac) besteht. Die grösste Lockwirkung wurde mit einem Gemisch der beiden Substanzen bei einem E-Anteil von 80–95% erzielt. Dodecylacetat (12:Ac) und Tetradecylacetat (14:Ac) wurden ebenfalls in den weiblichen Pheromondrüsen nachgewiesen, hatten aber im Freiland keinen Einfluss auf die Lockwirkung. G. lobarzewskii tritt seit einiger Zeit in der Schweiz als Schädling von Apfel und Zwetschge auf und ist an ihrem charakteristischem Frassgang leicht erkennbar. Die Art wurde bisher irrtümlich als G. janthinana bezeichnet. G. janthinana lebt auf Rosaceen, und wird vom gleichen Substanzpaar angelockt, allerdings bei umgekehrtem Mischungsverhältnis (20% E).
    Notes: Abstract As shown by chemical analysis and field trapping, the sex pheromone of Grapholita lobarzewskii consists of a blend of (E)-8-dodecenyl acetate and (Z)-8-dodecenyl acetate. Maximum attractiveness was found at 80–95%. Dodecyl acetate and tetradecyl acetate, both present in the female gland, did not affect trap catch. G. lobarzewskii has recently gained importance as a pest of apple and plum, but has so far been referred to as Grapholita janthinana. The latter is attracted to the same two compounds, but in reversed portions (20% E).
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    Entomologia experimentalis et applicata 48 (1988), S. 149-156 
    ISSN: 1570-7458
    Keywords: Formamidines ; chlordimeform ; Lepidoptera ; behaviour ; starvation ; survival ; development ; sublethal control
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les chenilles de troisième et cinquième stades de P. brassicae L. ont reçu une application superficielle de chlordiméforme, insecticide à la formamidine. Les doses inférieures à 335 μg/g ont été sublétales, provoquant plusieurs formes d'excitation. Bien que leur comportement soit redevenu normal en 24 heures, les troisièmes stades traités ont eu leur développement retardé et une mortalité accrue. Le traitement des chenilles plus âgées a eu moins d'effets. Une relation est suggérée entre ces observations et le régime alimentaire de cet insecte; une réduction de l'alimentation, plus importante chez les chenilles de troisième que de cinquième stade de P. brassicae, accompagne le début des altérations du comportement provoquées par le chlordiméforme. La discussion porte sur le mécanisme de contrôle sublétal du chlordiméforme, impliquant des effects immédiats et retardés.
    Notes: Abstract Larvae of the large cabbage white butterfly, Pieris brassicae L. are important pests of cruciferous crops. Third and fifth instars were treated topically with sublethal doses of the formamidine pesticide chlordimeform. A number of excitable actions were induced but they did not persist beyond 24 hours. Following the initial period, however, subsequent development was delayed and mortality increased, particularly when third instars were treated. Dosing fifth-instar larvae caused few further deaths. A link is suggested between these results and the nutritional status of the insects, and they are discussed in terms of how they might contribute towards control.
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    Entomologia experimentalis et applicata 48 (1988), S. 141-147 
    ISSN: 1570-7458
    Keywords: Lepidoptera ; aggregation behaviour ; feeding ; chlordimeform ; crop protection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Un des effets sublétaux du chlordiméforme, insecticide formamidine, est une réduction de la prise de nourriture, par suite de l'altération du comportement. Celle-ci implique une action stimulant l'activité locomotrice du quatrième stade de P. brassicae L., moins sensible aux effets sur l'alimentation. Le but de ce travail est d'examiner comment le chlordiméforme agit sur le comportement des chenilles du second stade. Des chenilles sur des feuilles trempées dans le chlordiméforme (10-6 à 10-2) sont vite excitées, leur déplacements s'accélèrent et les groupements formés sont tous instables, l'alimentation y étant généralement éphémère. L'excitation se réduit au bout de 24 heures, le groupements se reforment, et l'alimentation reprend, bien que pour les concentrations ≥10-4 M, les chenilles aient été encore dispersées entre 24 et 30 heures, au moment où elles commençaient à s'alimenter sur les résidus de chlordiméforme. La perturbation de la concentration des chenilles sur des disques témoins a montré une relation directe entre la taille du groupe et le taux de croissance larvaire. Nous en avons conclu que chez les espèces de lépidoptères qui consomment groupées, une interaction avec l'agrégation larvaire contribue significativement à l'effet du chlordiméforme sur l'alimentation. La discussion porte sur les conséquences pour la croissance et la survie larvaire, particulièrement en ce qui concerne l'installation des chenilles néonates.
    Notes: Abstract The behavioural basis for the reduction in feeding caused by the formamidine pesticide chlordimeform was investigated in second-instar larvae of the large cabbage white butterfly, Pieris brassicae L. Normally, these caterpillars feed communally. On chlordimeform-dipped leaves (10-6 M–10-2 M) they rapidly became excited, locomotion increased and only unstable aggregations formed in which any feeding was usually transient. Over 24 h excitation declined, aggregations re-formed and feeding was resumed. However, between 24 and 30 h, on leaves treated with chlordimeform solutions of 10-4 M or greater, larvae dispersed again. By altering the density of larvae on control discs a direct link was revealed between clump size and larval growth rates. It is concluded that, in species which feed gregariously, interference with larval aggregation contributes significantly to chlordimeform's effects on feeding and its involvement in a sublethal control mechanism in the field is discussed.
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  • 69
    ISSN: 1570-7458
    Keywords: Ostrinia nubilalis ; Pyralidae ; Lepidoptera ; Pseudoperichaeta nigrolineata ; Tachinidae ; Diptera ; larval development ; host-parasitoid relationship ; diapause ; development synchronization ; ecdysteroids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les interrelations entre O. nubilalis et le tachinidae P. nigrolineata ont été étudiées dans des conditions abiotiques telles que l'hôte présente un développement avec diapause. La rupture de la diapause a été obtenue par modifications des conditions abiotiques et/ou injection d'ecdystérone. Si le passage au froid a lieu 25 jours après la mue 4/5 et s'il dure 10 semaines, plus de 90% des larves non parasitées lèvent leur diapause. Le temps nécessaire pour obtenir la chrysalidation est corrélé avec l'âge à la mise au froid et surtout avec la durée du froid. Les injections d'ecdystérone, 25 jours après la mue 4/5, chez les larves non parasitées et n'ayant pas séjourné au froid, provoquent la levée de diapause dans un fort pourcentage de cas, mais seulement si les larves ont été transférées en photopériode longue; le temps de chrysalidation est fortement réduit chez les larves injectées par rapport aux témoins placés sous la même photopériode. Chez les larves d'O. nubilalis parasitées au début du 5ème stade larvaire, les larves de P. nigrolineata se développent de la même façon que chez les non diapausantes jusqu'au début du 2ème stade, puis la croissance s'arrête aux environs de 1 mg. Par modification des conditions abiotiques, la larve du parasitoïde ne reprend sa croissance qu'à la levée de diapause de l'hôte et continue ensuite son développement jusqu'à la pupaison qui intervient 25–30 jours après les modifications. Cette synchronisation étroite des développements du parasitoïde et de l'hôte peut être rompue par l'injection d'ecdystérone dans l'hôte; en effet, une faible dose induit la reprise de la croissance du parasitoïde, sans provoquer l'apolyse de l'hôte. Des doses plus élevées provoquent à la fois la reprise immédiate du développement de P. nigrolineata (la formation des pupes intervient alors 6–10 jours après) et l'apolyse de l'hôte. Le parasitoïde augmente la sensibilité de l'hôte: avec la même dose, le pourcentage d'apolyse est plus élevé chez les hôtes parasités que chez les non parasités.
    Notes: Abstract The developmental relationships between Ostrinia nubilalis Hübner (Lepidoptera, Pyralidae) and the tachinid parasitoid Pseudoperichaeta nigrolineata Walker (Diptera, Tachinidae) are described under abiotic conditions which induce development of the host with diapause. Diapause termination was accomplished by modifications of abiotic conditions and/or by ecdysterone injection. Pupation time was correlated with the age at chilling and with the chilling period. Ecdysterone injection in non-parasitized larvae, 25 days after the 4/5 moult, gave a high percentage of diapause termination only under a long day photoperiod and strongly reduced the pupation time. In diapausing larvae parasitized at the beginning of the fifth instar, P. nigrolineata larva develops in the same way as in non-diapausing ones during the first instar, but stops growth in the second, near a weight of 1 mg. When diapause was broken by modifications of obiotic conditions, the parasitoid larva resumes its growth only at host diapause termination (pupariae are obtained 25–30 days after the modifications). The close synchronization between parasitoid and host development is broken by injection of low dose of ecdysterone. Higher doses induce at once parasitoid growth (pupariae are obtained 6–10 days thereafter) and also host apolysis. The parasitoid larvae increase the host sensitivity to exogenous ecdysteroids.
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  • 70
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    Entomologia experimentalis et applicata 50 (1989), S. 125-132 
    ISSN: 1570-7458
    Keywords: Lepidoptera ; Pyralidae ; Chilo partellus ; spotted stalk borer ; spinning-off ; ballooning ; larval migration ; wind tunnel ; silk ; female weight ; batch size ; egg weight ; head capsule
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Le comportement aérostatique des chenilles néonates de C. partellus a été étudié dans un tunnel à vent. Environ 55% des chenilles néonates ont quité les jeunes plants de maïs sur des fils de soie, dans les deux heures qui ont suivi leur libération. Aucune corrélation significative n'a été observée entre l'activité de filature et le poids de la mère, le poids de l'oeuf et la taille de l'ooplaque. Les chenilles aérostatiques ou non étaient de même taille. Le date de ponte n'a pas influé sur le comportement aérostatique. Il y avait des différences significatives dans l'activité aérostatiques des chenilles suivant les mères, ce qui suggère que des facteurs maternels, différents de ceux examinés jouent un rôle important dans la dispersion des chenilles.
    Notes: Abstract The ballooning behaviour of first instar larvae of Chilo partellus (Swinhoe) (Lepidoptera: Pyralidae) was studied using a wind tunnel. About 55% of the newly hatched larvae left the young maize plants on silk threads within two hours after their release. No significant correlations were found between spinning-off activity and mother weight, egg weight and number of eggs per batch. Ballooning and non-ballooning larvae were of the same size. Time of oviposition did not influence the ballooning behaviour. There was significant variation in spinning-off activity between offspring from different individual females, however, which suggests that maternal factors other than those measured play an important role in larval dispersal.
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  • 71
    ISSN: 1570-7458
    Keywords: sex pheromone ; lima-bean pod borer ; Etiella zinckenella ; Lepidoptera ; Phycitidae ; (Z)-11-tetradecenyl acetate ; (E)-11-tetradecenyl acetate ; (Z)-9-tetradecenyl acetate ; tetradecyl acetate ; Hungary ; Egypt
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé A partir de femelles d'E. zinckenella d'origines hongroise et égyptienne, nous avons isolé quatre composés par chromatographie en phase gazeuse avec ionisation de flamme et électroantennographie (EAD): l'acétate de tétradécanyl, l'acétate (Z)-11-tétradécényl, l'acétate (E)-11-tétradécényl et l'acétate (Z)-11-tétradécényl. Les acétates monoinsaturés donnent les meilleures réponses en EAG parmi une série d'acétates tétradécényls et de tétradécénols. Les quatre composés mélangés dans les mêmes proportions que dans l'extrait de la phéromone ont attiré un nombre significatif de mâles tant en Egypte qu'en Hongrie. Dans un test préliminaire de soustraction, la meilleure capture a été réalisée par le mélange ternaire d'acétates monoinsaturés.
    Notes: Abstract Four compounds, tetradecyl acetate, (Z)-9-tetradecenyl acetate, (E)-11-tetradecenyl acetate and (Z)-11-tetradecenyl acetate were identified from female sex pheromone extracts of Hungarian and Egyptian lima-bean pod borers (Etiella zinckenella Tr., Lepidoptera: Phycitidae) by gas chromatography with flame ionization (FID) and electroantennographic (EAD) detection. In EAG studies these monoun-saturated acetates gave the best responses in a series of other tetradecenyl acetates and tetradecenols. The four component blend of the identified components in similar ratios as in the pheromone extract attracted significant numbers of male lima-bean pod borers in both Hungary and Egypt. In a preliminary subtraction test best capture was achieved by the ternary mixture of the monounsaturated acetates.
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  • 72
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    Entomologia experimentalis et applicata 52 (1989), S. 205-214 
    ISSN: 1570-7458
    Keywords: Spruce budworm ; Choristoneura fumiferana ; Lepidoptera ; Tortricidae ; food consumption and utilization ; spruce ; Picea glauca ; Picea rubra ; Picea mariana
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé L'auteur a déterminé la quantité d'aliments utilisées, à 22±0,5 °C, par des larves de Tordeuse des bourgeons de l'épinette parvenues à leur sixième stade de développement qui s'étaient nourries d'un régime artificiel et d'aiguilles de l'année en cours lyophilisées et réduites en poudre, prélevées à deux dates différentes, à 10 jours d'intervalle, et provenant d'épinettes blanchés (Picea glauca [Moench] Voss), d'épinettes rouges (Picea rubra Sarg.) et d'épinettes noires (Picea mariana [Mill.] B.S.P.). Les femelles ont invariablement ingéré une quantité significativement plus importante de tous les régimes que les mâles, consommant 24% de plus d'aiguilles d'épinette noire et 73% de plus d'aiguilles d'épinette blanche. Les femelles prenaient en général plus de temps pour parvenir au stade de chrysalide et avaient un taux d'utilisation des aliments significativement plus élevé. L'efficacité nette de la croissance chez les deux sexes ne présentait toutefois aucune différence significative. La performance des larves ayant ingéré des aiguilles provenant de deux classes d'âge différait de façon significative mais non pas uniforme d'un régime à l'autre: les aiguilles d'épinette blanche plus récentes donnaient une performance généralement plus élevée contrairement aux aiguilles plus jeunes d'épinette rouge et d'épinette noire. Les larves ingéraient une quantité significativement plus élevée, avaient un taux de consommation et de croissance supérieur et augmentaient davantage leur biomasse avec des aiguilles d'épinette blanche. L'efficacité d'utilisation des aliments et le taux de croissance relatif étaient de faibles à modérément faibles pour un lépidoptère arboricole phyllophage; la vitesse d'ingestion relative était élevée. La qualité des aiguilles des trois essences d'épinettes était faible. Les aiguilles d'épinette blanche permettaient aux larves d'avoir une performance significativement plus élevée, performance mesurée à partir de plusieurs critères, alors que les aiguilles d'épinette rouge et d'épinette noire donnaient une performance égale. La supériorité des performances obtenues avec l'épinette blanche explique la plus grande vulnérabilité de cette essence à la Tordeuse des bourgeons de l'épinette.
    Notes: Abstract The effects of tree species, shoot age, and sex of larvae on food consumption and utilization were investigated in a factorial experiment. Diets prepared from lyophilized and powdered current-year shoots, from two age classes (sample dates) of Picea glauca (Moench) Voss, Picea rubra, Sarg., and Picea mariana (Mill.) B.S.P., were evaluated for eight performance criteria. All factors had significant effects on all criteria except for tree species on assimilation efficiency, shoot age on development time, and sex on net growth efficiency. Eight of the possible 24 two-factor interactions and one of the possible eight three-factor interactions were significant. Food utilization efficiencies and relative growth rate were in the low and moderate characterization limits for immature arthropods; relative consumption rates were high. The higher performance values on Picea glauca were related to this species greater vulnerability to spruce budworm. Performance criteria of similar larvae on an artificial diet were compared with those on the foliage-diets.
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  • 73
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    Entomologia experimentalis et applicata 53 (1989), S. 81-87 
    ISSN: 1570-7458
    Keywords: Lepidoptera ; Noctuidae ; sex pheromone ; wind tunnel ; sex attraction ; (Z)-11-hexadecenyl acetate ; (Z)-9-tetradecenyl acetate ; (Z)-11-hexadecenal ; (Z)-11-hexadecenol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé L'observation et la comptabilisation des vols orientés et des atterrissages des mâles de Mamestra suasa (Den. & Schiff.) (Lepidoptera; Noctuidae) sur une source de phéromone de synthèse ont mis en évidence un mélange attractif appelé mélange B et constitué par 100 ng de Z11-16: Ac et 1 ng de Z11-16: Ald. L'attraction et l'atterrissage sont sous la dépendance du mélange de ces 2 composés. Les variations de leurs proportions relatives affectent les différentes phases du comportement de vol des mâles. L'addition de 10 ng d'acétoxy-1 tetradécène-9 Z (Z9-14: Ac) diminue significativement les proportions de vols orientés et d'atterrissages par rapport aux réponses obtenues avec le mélange B seul. L'effet inhibiteur de cette molécule sur l'attractivité du mélange B et la présence chez M. suasa d'un récepteur spécialisé dans la perception de ce composé suggèrent que le Z9-14: Ac est impliqué dans la communication chimique entre M. suasa et d'autres espèces sympatriques. L'addition d'hexadécènol-11 Z (Z11-16: OH) au mélange B à la dose de 1 ou 10 ng ne modifie pas les réponses des mâles. Ce composé ne semble pas impliqué dans la communication chimique chez M. suasa.
    Notes: Abstract The upwind flight and landing responses of male Mamestra suasa (Den. & Schiff.) (Lepidoptera; Noctuidae) to various synthetic chemicals were studied in a wind tunnel. A mixture of (Z)-11-hexadecenyl acetate (Z11-16: Ac) and (Z)-11-hexadecenal (Z11-16: Ald) elicited upwind flight responses past the midpoint of the wind tunnel, and both components were necessary for landing of the males to occur at the pheromone source point. The best response to the mixtures tested was to a ratio 100:1 (ng) of Z11-16: Ac and Z11-16: Ald (blend B). The addition of (Z)-9-tetradecenyl acetate (Z9-14: Ac) (10 ng) to blend B resulted in a significant decrease of upwind flight and landing responses. The inhibitory effect of this chemical when it is mixed with blend B, and the presence of a specific receptor for this compound in sensilla trichodea of male M. suasa, suggest that Z9-14: Ac is involved in the chemical communication between M. suasa and other sympatric species. The addition of (Z)-11-hexadecenol (Z11-16: OH) (1 or 10 ng) to blend B had no effect on male upwind flight and landing responses. This compound does not seem to be involved in the chemical communication of this species.
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  • 74
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    Entomologia experimentalis et applicata 48 (1988), S. 213-223 
    ISSN: 1570-7458
    Keywords: Lepidoptera ; Yponomeutidae ; interspecific crosses ; hybrids ; sex-pheromone communication ; host-plant preference
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé 1. Des individus d'espèces très proches à l'intérieur du complexe Yponomeuta padellus ont été croisés; les hybrides ont été croisés entre eux et leurs fécondité et viabilité examinées. 2. Le taux d'accouplements a été généralement plus faible que celui des témoins. Les croisements Y. malinellus x Y. rorellus, Y. padellus x Y. rorellus, et Y. rorellus x Y. malinellus n'ont donné aucune descendance, tandis que les chenilles de Y. malinellus x Y. cagnagellus, Y. padellus x Y. cagnagellus et Y. padellus x Y. malinellus sont mortes avant le stade imaginal. Bien que des descendants féconds des deux sexes pouvaient être obtenus à partir de la plupart des croisements, leurs effectifs étaient faibles. Seuls les croisements où intervenaient des femelles de Y. cagnagellus, ont fourni assez de filles pour permettre des expériences avec des phéromones. 3. La viabilité, le rythme circadian de l'activité sexuelle, les réponses aux phéromones et le choix de la plante pour la ponte ont été examinés chez les hybrides des 3 croisements réussis avec Y. cagnagellus comme mère. 4. Le poids des chrysalides et la durée du développement de cette progéniture a montré une dominance de Y. cagnagellus, tandis que les caractères morphologiques étaient intermédiaires. Des indices d'un développement difficile ont été une modification du rythme d'éclosions et un biais dans la fréquence des sexes. On a aussi, observé une certaine stérilité, c'està-dire que 10% environ des F1 cagnagellus x malinellus étaient intersexués, et que la plupart des femelles F1 cagnagellus x rorellus n'ont pas présenté de comportement d'appel. Les femelles ont manifesté une légère préférence pour appeler à partir de la plante hôte maternelle. L'âge du premier appel a révélé une dominance partielle de Y. malinellus et de Y. padellus. 5. Les mâles hybrides ont répondu fortement aux phéromones des femelles hybrides correspondantes. Les réponses des hybrides mâles F1 et F2 aux phéromones parentales ont montré que la réponse était orientée spécifiquement par la dominance de Y. cagnagellus sur Y. malinellus et une codominance de Y. cagnagellus et Y. padellus. 6. Ces résultats ont indiqué les possibilités d'échanges géniques en l'absence de barrière avant la copulation. Ainsi, l'isolement reproductif des 4 espèces est maintenu par la spécificité des phéromones sexuelles femelles et renforcé par les signaux du comportement de pariade.
    Notes: Abstract Interspecific crosses were made among four closely related members of the Yponomeuta padellus-complex. The results show the potential for gene exchange in the absence of pre-mating barriers. However, mating success was generally lower in the interspecific crosses than in the control crosses. No progeny were obtained from crosses between Y. malinellus Zeller x Y. rorellus (Hübner), Y. padellus (L.) x Y. rorellus and Y. rorellus x Y. malinellus, whereas larvae from Y. malinellus x Y. cagnagellus (Hübner), Y. padellus x Y. cagnagellus and Y. padellus x Y. malinellus did not reach the adult stage. Hybrids of three successful crosses with Y. cagnagellus as maternal species were examined for viability, circadian rhythm of sexual activity, sex-pheromone responses and female host-plant preferences. Developmental problems were found for the crosses cagnagellus x malinellus and cagnagellus x rorellus. Pupal weights and developmental time indicated dominance of Y. cagnagellus, while morphological characters were intermediate to the parents. The age of first calling indicates incomplete dominance of Y. malinellus and Y. padellus, while female moths showed a slight preference for the maternal host plant for calling activities. Hybrid males showed high responsiveness to the corresponding hybrid females. Responses to the parental species indicate that the inheritance of the pheromone-response specificity is governed by a dominance of Y. cagnagellus over Y. malinellus and co-dominance between Y. cagnagellus and Y. padellus.
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    Entomologia experimentalis et applicata 50 (1989), S. 199-207 
    ISSN: 1570-7458
    Keywords: Lepidoptera ; Pyralidae ; Chilo partellus ; spotted stem borer ; fecundity ; reproductive strategy ; female size ; batch size ; egg weight
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé La ponte de C. partellus Swinhoe a été étudiée au laboratoire pendant les trois premières nuits de la ponte. Plus de 50% des ooplaques et des oefs ont été pondus pendant la première nuit. La taille des ooplaques diminue avec le temps, tandis que le poids moyen des oeufs reste constant. Les grosses femelles pondent des ooplaques et des oeufs plus grands que les petites. Elles sont aussi plus fécondes, mais c'est seulement à la seconde nuit de ponte qu'est due cette différence. Le reproduction diminue beaucoup avec le temps. L'affectation aux premiers oeufs des réserves utilizées pour la reprodution semble plus importante que l'émission d'oeufs régulièrement répartis dans le temps. Les grosses femelles utilisent proportionnellement plus de ressources à la production d'oeufstardifs. Les gros oeufs contiennent vraisemblablement plus de vitellus que pourrait être nécessaire pour le comportement aérostatique des chenilles néonates.
    Notes: Abstract The egg laying pattern of the spotted stalk borer on sorghum and maize, Chilo partellus (Swinhoe) (Lepidoptera: Pyralidae) was studied during the first three nights of oviposition under laboratory conditions. More than 50% of both eggs and egg batches are laid during the first night of oviposition. Batch size decreases with time, whereas mean egg weight remains constant. Larger females lay both larger eggs and egg batches than smaller ones. They are also more fecund but it is only the second night of oviposition that contributes significantly to this difference. The reproductive effort decreases much with time. Allocation of reproductive reserves to early eggs seems more important than having eggs evenly distributed over time. Larger females use proportionally more resources to the production of late eggs. Large eggs are likely to contain more yolk which could be of importance for the ballooning behaviour of newly hatched larvae.
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  • 76
    ISSN: 1570-7458
    Keywords: Inheritance ; receptor ; single sensillum ; electrophysiology ; Ctenopseustis ; Lepidoptera ; Tortricidae ; olfactory response ; sex pheromone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les réactions olfactives des sensilles mâles sensibles aux phéromones ont été examinées par enregistrement de l'extrémité de la sensille chez les tordeuses C. obliquana Walker et C. sp. ‘ropeana’. Les enregistrements ont porté sur 281 sensilles des lignées parentales et des croisements réciproques de F1, F2 et de croisements en retour maternel et paternel. Les résultats des enregistrements d'une sensille ont été soumis à une analyse en composantes principales. Chez les mâles de chaque lignée parentale un seul type physiologique de sensille a été découvert; une cellule répond par un pic grand au principal constituant de la phéromone femelle conspécifique. (Z)-8-acétate tétradécényl (Z8-14:OAc) pour C. obliquana, et (Z)-5-acétate tétradécényl (Z5-14:OAc) pour C. sp. ‘ropeana’. Une seconde type de cellule dans les sensilles des deux espèces de mâles présente un pic petit pour Z5-14:OAc et pour l'acétate tétradécyl (14:OAc) chez C. obliquana, et pour C. sp. ‘ropeana’ au Z8-14:OAc. Les réponses des sensilles des différents types de mâles hybrides sont plus hétérogènes que celles des sensilles de leurs pères. Un schéma général pourrait cependant être décelé, correspondant au schéma prévu avec une hérédité d'un facteur dominant liée au sexe sur le chromosome Z de C. sp. ‘ropeana’. La variation plus accentuée chez les hybrides ne peut être expliquée par ce modèle, et pourrait impliquer des gènes additionnels.
    Notes: Abstract The olfactory response from male pheromone sensitive sensilla was investigated in the endemic New Zealand brownheaded leafrollers Ctenopseustis obliquana (Walker) and C. sp. ‘ropeana’ (Lepidoptera, Tortricidae). The responses from 281 sensilla from the parental strains and from both the reciprocal crosses, including F1, F2 and maternal and paternal backcrosses were recorded, and statistically analysed using a multivariate analysis. In males of both the parental strains, a large amplitude cell responded to the main pheromone component of the conspecific female, in C. obliquana (Z)-8-tetradecenyl acetate (Z8-14:OAc) and in C. sp ‘ropeana’ (Z)-5-tetradecenyl acetate (Z5-14:OAc). Both male types also possessed a small amplitude cell, which in C. obliquana responded weakly to Z5-14:OAc and tetradecyl acetate (14:OAc), and in C. sp ‘ropeana’ responded to Z8-14:OAc. The responses from the different types of hybrid males were more variable than the responses from parental males. A main pattern could, however be seen, corresponding with the expected pattern in a sex-linked inheritance on the Z-chromosome of a C. sp ‘ropeana’ type dominant genetic factor. The more pronounced variation in the hybrids could not be explained by this model, and might be due to the involvement of additional genes.
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    Entomologia experimentalis et applicata 53 (1989), S. 257-265 
    ISSN: 1570-7458
    Keywords: Antifeedant ; insecticide ; bisabolangelone ; analog ; feeding ; growth ; molting ; mortality ; sesquiterpenoid ; development ; phago-stimulant ; Pieris brassicae L. ; Lepidoptera ; Pieridae ; Angelica silvestris L. ; Umbelliferae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Bisabolangelone und drei Analoge wurden unter Laboratoriumsbedingungen auf ihre frasshemmende Wirkung in Raupen von Pieris brassicae L. (Lepidoptera: Pieridae) geprüft. Die Resultate von Zweifach-Wahlversuchen zeigten, dass sowohl die frasshemmende als auch die insektizide Wirkung von Bisabolangelone in den Analogen stark reduziert ist oder ganz verloren ging. Weitere Untersuchungen mit niedrigen Bisabolangelone-Dosen zeigten, dass das Fehlen von wohlschmeckender Nahrung zu einer drastischen Reduktion der Nahrungsaufnahme und des Wachstums der Raupen sowie zur Verhinderung der Häutung und zu hoher Mortalität führt. Deformationen, wie sie von bisabolangelone-behandelten Vorratsschädlingen gemeldet wurden, konnten bei P. brassicae nicht beobachtet werden.
    Notes: Abstract Bisabolangelone and three analogs were assayed, under laboratory conditions, for their antifeedant activity against Pieris brassicae L. (Lepidoptera: Pieridae) larvae. The results of dual-choice studies revealed that the potent antifeedant activity of bisabolangelone is greatly reduced or lost in the analogs. Insecticidal activity observed in the former was not detected either. Further studies using the lower rates of bisabolangelone showed that the absence of a preferable food resulted in a drastic reduction in feeding and growth, and produced high mortality and inhibition of molting. No developmental deformities reported in stored product insects treated with bisabolangelone were observed in P. brassicae during our studies.
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  • 78
    ISSN: 1572-8889
    Keywords: mate-locating behavior ; butterfly ; Euphydryas chalcedona ; Lepidoptera ; pupation sites ; sexual discrimination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Males of the checkerspot butterfly (Euphydryas chalcedona)patrol and perch near but not on the larval foodplant in search of females. Experiments with tethered butterflies show that searching males chase virgin females for longer times than they do mated females or males. The larvae leave the larval food-plant to pupate. The correspondence between the distance from the larval foodplant to pupation sites and where males search for females suggests that male mate-locating behavior has evolved to maximize the rate of encounters with newly emerged, virgin females. These conclusions are compared to a recent analysis of butterfly mating systems by Odendaal et al. (Am. Nat. 125: 673–678, 1985).
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  • 79
    ISSN: 1572-8889
    Keywords: Grapholita molesta ; Lepidoptera ; optomotor anemotaxis ; pheromone ; counterturn ; zigzag ; flight ; orientation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract As the ratio of (E)-8-dodecenyl acetate (E8–12∶Ac) to (Z)-8-dodecenyl acetate (Z8–12∶Ac) increased past optimal low levels in the pheromone blend, fewer males were able to fly 2.5 m upwind to the source. The tracks of males that flew in plumes of such high-(E)off-blends were slower and narrower than those of males flying to lower-(E)blends. The tracks were narrower, first of all, because as the proportion of E8–12∶Ac increased, the males steered more into the wind. More of their thrust was directed upwind and therefore their groundspeed to either side of the windline was reduced. In addition, males also reduced their airspeeds to high-(E)blends, which contributed to the decreased groundspeeds and narrower tracks. No significant changes in the frequency of counterturning were found in response to increasing proportions of E8–12∶Ac. The inability to continue upwind flight in a plume of an off ratio was indicated by in-flight arrestment in the plume. Arrestment resulted from changes in the course angles steered by the males and the airspeeds flown.
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    Entomologia experimentalis et applicata 34 (1983), S. 203-205 
    ISSN: 1570-7458
    Keywords: Lepidoptera ; Sesiidae ; Synanthedon vespiformis ; Paranthrene tabaniformis ; Chamaesphecia empiformis ; Chamaesphecia tenthrediniformis ; Attractants ; Pheromones ; Clearwing moths ; Nemapogon
    Source: Springer Online Journal Archives 1860-2000
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  • 81
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    Entomologia experimentalis et applicata 34 (1983), S. 65-70 
    ISSN: 1570-7458
    Keywords: Insect growth regulators ; Anti-juvenile hormone ; Fluoromevalonate ; Precocious metamorphosis ; Premature pupation ; Ecdysis ; Fall webworm ; Hyphantria cunea ; Lepidoptera ; Arctiidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Fluormevalosäure (FMev), bekannt als ein spezifischer Inhibitor der Biosynthese des Juvenilhormons (JH) in Insekten, wurde in 0,1–50 μg/Tier Dosis topikal an 3., 4. und 5. Larvenstadien von Hyphantria cunea getestet. Die Raupen wurden auf einem semi-synthetischen, künstlichen Nährboden bei 25° und unter Langtagsbedingungen (18 : 6 St., Licht/Dunkel) gezüchtet. Diese Verbindung rief drei verschiedene Typen spezifischer Reaktionen hervor: 1) verfrühte Metamorphose, 2) gehemmte Häutung und 3) verlängerte Larvenentwicklung. Vor der verfrühten Verpuppung wurde normales Verhalten beobachtet. Die Larven des 3. oder 4. Stadiums häuteten sich meist erst nach einem interkalaren Larvenstadium in verfrühte Puppen. Unter den drei Larvenstadien erwies sich das 5. Stadium gegen die Anti-JH-Verbindung am empfindlichsten. In allen getesteten Entwicklungsphasen wiesen die frisch gehäuteten Larven die höchste Empfindlichkeit gegen FMev auf. Nach der Häutung wurde stufenweises Absinken der FMev-Empfindlichkeit beobachtet, im 5. Larvenstadium verursachte die Verbindung jedoch selbst am letzten Tag des Wachstums zu einen relativ hohen Prozentzahl verfrühte Verpuppung. Eine zweite typische Wirkung von FMev war die Hemmung der Häutungsprozesse. Zwei grundlegende Stufen der Häutungsstörungen unterschieden sich voneinander: 1) Als Folge der Anwendung hoher Dosen von FMev konnte die Mehrzahl der Raupen die alte Larvenkutikula nicht öffnen und ging deswegen in kurzer Zeit zugrunde. 2) Bei Behandlung mit niedrigen Dosen der Anti-JH-Verbindung häuteten sich einige Hyphantria-Larven scheinbar normal; nach der Häutung waren aber alle unfähig, die normalen Bewegungen und die Nahrungsaufnahme fortzusetzen. Auch die vorzeitigen Puppenhäutungen wurden in meisten Fällen durch die Anti-JH-Behandlung gehemmt. Die morphogenetischen Wirkungen von FMev konnten durch eine topikale Behandlung mit Hydroprene, einem hochaktiven JH-Analogen, vollständig oder teilweise verhindert werden.
    Notes: Summary Fluoromevalonate (FMev, ZR-3516) known as an inhibitor of JH biosynthesis was topically applied in 0.1 to 50 μg/specimen doses to the 3rd, 4th, and 5th instar caterpillars of Hyphantria cunea Drury. The anti-JH compound induced 3 main types of specific responses: 1) precocious metamorphosis, 2) inhibition of ecdysis, and 3) prolongation of larval development. Precocious pupation was accompanied by behavioural events typical of normal pupation. Third and 4th instar larvae metamorphosed prematurely mostly with the intervention of an intercalary larval instar. The 5th instar exhibited the highest sensitivity to the anti-JH agent. Within each larval stage the freshly moulted insects proved to be the most susceptible to FMev. Afterwards, the incidence of morphogenetic reaction gradually decreased with age. In another fraction of Hyphantria larvae not responding with precocious pupation, FMev evoked varying degrees of ecdysial disturbance which always resulted in the death of caterpillars. In most cases the anti-JH compound inhibited the premature pupal moult, too, and these affected insects died as tanned pharate pupae. A complete or partial “rescue” from the effects of FMev was elicited, if simultaneously or subsequently, a single topical dose of a JH analogue, hydroprene was also administered.
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  • 82
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    Entomologia experimentalis et applicata 37 (1985), S. 13-16 
    ISSN: 1570-7458
    Keywords: spruce budworm ; Choristoneura fumiferana ; Lepidoptera ; Tortricidae ; calling behavior ; sex pheromone ; bioassay
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Des expériences ont été menées au laboratoire pour examiner si la phéromone sexuelle synthétique de C. fumiferana pouvait altérer le comportement d'appel de femelles vierges de la même espèce. Un appareil a été conçu pour libérer alternativement — à des intervalles déterminés — un courant d'air portant de la phéromone sexuelle ou un courant d'air pur, dans plusieurs flacons contenant des femelles vierges. Le comportement sexuel de mouches de 0 et 2 jours a ainsi été observé. Indépendamment de l'exposition des femelles à la phéromone, il y avait deux pics quotidiens d'activité d'appel, l'un dans l'après-midi et l'autre après le crépuscule. Des papillons exposés au 1×10−6 mg ou 1×10−3 mg de phéromone avaient un premier pic d'appel au moins antérieur de 2 heures par rapport aux témoins. Ainsiily a vait un plus grand nombre de papillons engagés dans une activité d'appel en présence de la phéromone que chez les témoins.
    Notes: Abstract The calling behaviour of 0-day-old and 2-day-old virgin female eastern spruce budworm moths, Choristoneura fumiferana (Clem.) was observed during exposure to different concentrations of the synthetic female sex pheromone. Regardless of whether the females were exposed to pheromone or not, there were two daily peak periods of calling activity, one in the afternoon and the other after dusk. Those moths exposed to pheromone commenced calling at least 2 h earlier during their first peak of calling activity. Also, a greater number of moths engaged in calling when exposed to pheromone than those under control conditions.
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  • 83
    ISSN: 1570-7458
    Keywords: Ostrinia nubilalis ; Pyralidae ; Lepidoptera ; Pseudoperichaeta nigrolineata ; Tachinidae ; Diptera ; larval development ; host-parasitoid relationship ; development synchronisation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les relations physiologiques entre O. nubilalis et le tachinidae P. nigrolineata ont été étudiées dans des conditions abiotiques telles que l'hôte présente un développement sans diapause. Le parasitoïde ralentit la prise de poids de l'hôte: le poids maximal des chenilles parasitées ne représente que 78% de celui des chenilles saines. Seule la durée du 5ème stade est significativement plus longue chez les chenilles parasitées que chez les saines (10,4 contre 8,0 jours). L'influence de l'hôte sur le développement du parasitoïde à été expérimentée en parasitant des stades 2 à 5 d'O. nubilalis. Lorsque l'infestation a lieu au stade 2, le développement larvaire complet du parasitoî de dure deux fois plus longtemps que lorsque l'infestation a lieu au stade 5. Le meilleur rendement en pupes (50%) est obtenu lorsque l'infestation a lieu au stade 3. Il a été montré qu'il existe une bonne synchronisation entre le développement de l'hôte et de son parasitoî de. Il y a 4 phases physiologiques du développement larvaire de P. nigrolineata qui semblent nécessiter un signal provenant de l'hôte pour être dépassées. Ainsi peuvent être mis en relation: — le début de la croissance de la larve néonate du parasitoî de et l'ecdysis 3/4 de l'hôte; — la première mue du parasitoïde et l'ecdysis 4/5 de l'hôte; — la reprise de la croissance du stade II du parasitoïde, vers un poids de 1 mg et la remontée des taux d'ecdystéroïdes au milieu du stade 5 de l'hôte. et probablement, — la seconde mue du parasitoïde et l'apolyse nymphale de l'hôte. Les expérimentations vont se poursuivre pour déterminer les facteurs en cause. Ces phénomènes de synchronisation seront aussi étudiés dans le cas de la diapause de l'hôte.
    Notes: Abstract The physiological relationships between Ostrinia nubilalis Hübner and its tachinid parasitoid Pseudoperichaeta nigrolineata Walker are described under abiotic conditions which induce development of the host without diapause. The parasitoid lowers the larval growth of the host: the maximal weight attained by the parasitized larvae represented only 78% of that of healthy ones. The duration of the last larval host instar increased to 10.4 days in parasitized O. nubilalis compared to 8.0 days in unparasitized ones. The influence of the host on the parasitoid development was studied experimentally after parasitization of O. nubilalis larvae of instars 2 to 5. When the second larval instar of the host is parasitized, the overall duration of parasitoid larval development lasts twice as long as when the fifth instar is parasitized. The best yield of parasitoid pupariae (50%) is obtained when parasitization occurs in instar 3. We show that good synchronisation exists between the larval development of the host and its parasitoid. There are four phases of parasitoid development which would appear to require a ‘signal’ from the host: the start of the growth of newly hatched parasitoid larvae and the 3rd to 4th instar ecdysis of the host; the first moulting of the parasitoid and the 4th to 5th instar ecdysis of the host; the growth resumption of the parasitoid instar II (weight about 1 mg) and the small rise of the ecdysteroid level in the middle of host instar 5; and in all probability, the second parasitoid moulting and the larval-pupal apolysis of the host.
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    Entomologia experimentalis et applicata 45 (1987), S. 227-235 
    ISSN: 1570-7458
    Keywords: oviposition deterrent ; pheromone ; field experiments ; pre-oviposition behaviour ; dispersal ; Pieris brassicae ; Lepidoptera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé L'étude de l'efficacité de la phéromone dissuasive de la ponte (ODP) de P. brassicae a été effectuée au cours de petites expériences dans la nature. Dans des cages contenant des choux traités à l'ODP et des choux témoins, des femelles isolées ont été lâchées et leur comportement a été suivi jusqu'à ce qu'elles aient choisi un lieu de ponte. Dans les expériences sans plantes traitées à l'ODP, la ponte avait lieu uniformément sur les plantes de la cage. En présence de la phéromone, la ponte était concentrée sur les plantes situées sur deux côtés de la cage. La distribution des tentatives de ponte sur plantes témoins et traitées dans les expériences avec phéromone ne différait cependant pas de la distribution observée dans les expériences témoins. Ceci montre que pour ces conditions expérimentales dans la nature, l'efficacité finale de la phéromone est nulle. Cependant, la durée du comportement de préponte et le nombre moyen d'atterrissages pendant la sélection du lieu de ponte par les pondeuses était tous les deux accrus significativement en présence de phéromone. L'ODP a modifié aussi le nombre d'atterrissages sur les plantes témoins qui étaient plus élevés dans les expériences avec phéromone que dans les expériences témoins. Sans phéromone, les femelles libérées au centre de la cage avaient tendance à voler vers les parois de la cage. La présence d'ODP a stimulé ce comportement et, de plus, a dissuadé le retour des femelles vers le centre de la cage, réduisant ainsi la ponte sur les plantes au centre du lot. Des expériences de laboratoire avec des feuilles de plantes traitées dans la nature ont montré la persistance de la phéromone pendant au moins 5 jours dans les conditions de la nature. Nous en avons conclu que, dans la nature, ODP agit en modifiant le comportement de pré-ponte des femelles et en stimulant l'activité de dispersion, plutôt qu'en fournissant une protection absolue contre la ponte de P. brassicae.
    Notes: Abstract In small-scale field experiments the potency of the oviposition deterring pheromone (ODP) of Pieris brassicae as a pest control agent has been studied. In a field cage containing control and ODP-treated cabbage plants, single females were released and their behaviour observed until they had selected an oviposition site. In experiments without ODP-treated plants, oviposition occurred evenly on plants throughout the cage. In the presence of the pheromone, oviposition was concentrated on plants along two sides of the cage. The distribution of oviposition attempts on control and treated plants in pheromone experiments, however, was not significantly different from that in the control experiments. This means that under these field conditions, i.e. within a cage, the ultimate effectiveness of the pheromone is nil. However, the duration of pre-oviposition behaviour and the mean number of landings during the site-selection process by ovipositing females were both found to be significantly increased in the presence of the pheromone. The ODP also affected the relative number of landings on control plants, which was higher in the pheromone runs than in the control runs. Without pheromone, females released from the center of the cage tended to fly to the sides of the cage. The presence of ODP stimulates this flight behaviour and, moreover, discourages females from returning to the center of the cage, thereby reducing oviposition on central plants in the field plot. Laboratory experiments with leaves from treated field plants indicated persistence of the pheromone under field conditions for at least 5 days. It is concluded that in the field the ODP acts as a modifier of female pre-oviposition behaviour and stimulates dispersal activity, rather than giving absolute protection against P. brassicae oviposition.
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    Entomologia experimentalis et applicata 46 (1988), S. 227-232 
    ISSN: 1570-7458
    Keywords: tri-trophic level interactions ; nicotine ; alkaloid ; Hyposoter annulipes ; Hymenoptera ; Ichneumonidae ; fall armyworm ; Spodoptera frugiperda ; Lepidoptera ; Noctuidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Des quantités croissantes de nicotine dans l'alimentation ont prolongé la durée du développement des chenilles saines, bien que l'effet ait chuté aux concentrations les plus élevées. Le sexe de la noctuelle n'a pas eu d'effet sur la durée du développement ou l'action de la nicotine. L'influence de la nicotine sur le poids des chrysalides est inhabituel, en ce sens que les chrysalides les plus lourdes ont été obtenues aux concentrations moyennes. Des hypothèses sont proposés sur l'origine de ce phénomène. La mortalité et la durée de développement de H. annulipes ont augmenté et le poids des adultes a diminué quand la concentration de l'aliment de l'hôte en nicotine s'est élevée. L'effet différente de la nicotine sur des générations successives a pu provenir de modifications de la toxicité de la nicotine en fonction de changements dans la qualité de l'aliment. Quoi qu'il en soit, l'augmentation de la concentration de la nicotine dans l'alimentation de l'hôte a eu un effet négatif cohérent sur la valeur adaptative de H. annulipes.
    Notes: Abstract Experiments were conducted to determine the influence of nicotine (at a range of concentrations) in the food of an herbivorous host on the development, size and survival of its parasitoid. Fall armyworms, Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae) were reared on diets of 0, 0.025, 0.050 and 0.075% nicotine and exposed to parasitism by Hyposoter annulipes (Hymenoptera: Ichneumonidae). As nicotine concentration increased parasitoid mortality and development time increased and adult weight decreased. Development time, pupal weight and survival were recorded for unparasitized armyworms. Unparasitized fall armyworms showed lengthened development and higher mortality but pupal weights were greatest at intermediate nicotine concentrations.
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  • 86
    ISSN: 1570-7458
    Keywords: Lepidoptera ; Arctiidae ; Sex Pheronome ; Behaviour ; Electroantennography ; Physico-chemistry ; (Z,Z)-3,6-Cis-9S,10R-epoxyheneicosadiene ; (Z,Z)-3,6-Cis-9,10-epoxyeicosadiene ; (Z,Z,Z)-3,6,9-heneicosatriene ; Lépidoptère ; Arctiidae ; Phéromone sexuelle ; Comportement ; Electroantennographie ; Physicochimie ; Epoxy-9S,10R-(Cis) hénéicosadiène-3Z,6Z ; Epoxy-9,10-(Cis) éicosadiène-3Z,6Z ; Hénéicosatriène-3Z,6Z,9Z
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Abstract The hexanic extracts from pheronomal glands of T. jacobaeae virgin females have been studied. Gas-chromatographic and mass-spectrometric analyses of the main component (no 1) (98%) in combination with behavioral and electrophysiological bioassays allowed us to determine its structure and absolue configuration: (Z,Z)-3,6-Cis-(S,R)9,10-epoxyheneicosadiene previously described in other Arctiid moths. A minor constituent (no 2) (1.5%) was identified as (Z,Z)-3,6-Cis-(S,R)9,10-epoxyeicosadiene by comparison with synthetic compound. This structure is a new one for a lepidoptera sex pheromone. The third component (no 3) of the same extracts has the same physico-chemical data as those of a previously reported constituent of another Arctiid moth: (Z,Z,Z)-3,6,9 heneicosatriene.
    Notes: Abstract Les analyses physico-chimiques d'extraits hexaniques de glandes à phéromone de femelles vierges de T. jacobaeae, associées à des études du comportement sexuel et à l'électroantennographie, ont permis d'identifier le composé majoritaire (98%) comme étant l'époxy-9S,10R-(Cis)-hénéicosadiène-3Z,6Z (no 1) et de déterminer sa configuration absolue. Les analogies entre les spectres du composé no 2 (1,5%) et ceux de l'époxy-9S,10R éicosadiène-3Z,6Z de synthèse nous conduisent à proposer cette structure pour ce constituant minoritaire. Le troisième produit (0,5%) possède les caractéristiques physico-chimiques de l'hénéicosatriène-3Z,6Z,9Z (no 3). Les produits 1 et 3 ont déjà été identifiés comme constituants de phéromones d'Arctiidae tandis que le produit 2 est décrit ici pour la première fois dans une sécrétion phéromonale de Lépidoptère.
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    Entomologia experimentalis et applicata 43 (1987), S. 251-260 
    ISSN: 1570-7458
    Keywords: spruce budworm ; Choristoneura fumiferana ; Lepidoptera ; Tortricidae ; white spruce ; Picea glauca ; food consumption ; survival ; development time ; artificial diet
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé De la poudre lyophilysée de pousses de l'année de Picea glauca a été introduite dans le régime de chenilles du 6ème stade de Choristoneura fumiferana: 20% de poudre de pousses, 1.2% de gélifiant, 78.8% d'eau. Il est ainsi possible de déterminer à 2 mg près la quantité d'aliment consommée par chaque chenille, et, ainsi, de calculer, pour chacune, l'indice alimentaire, dont la prise de nourriture est l'une des variables. Avec de tels régimes préparés à partie de pousses recueillies au cours de 1983, on a constaté que la date de nymphose, la quantité consommée, et le poids ultérieur des papillons dépendaient du sexe de la chenille. En général, les chenilles femelles se nymphosent plus tard, consomment plus et donnent des papillons plus lourds (poids sec) que les chenilles mâles. L'efficacité de l'assimilation et celle de la transformation en biomasse de papillon ne différent pas suivant les sexes, c'est-à-dire qu'ils ont la même aptitude à digérer les pousses. Les taux de survie de chenille à nymphe et de nymphe à imago ne différent donc pas. Cependant, certains de ces paramètres et d'autres changent en fonction de l'âge des pousses annuelles. Quand elles ont été récoltées 7 jours après le débourrement (il a lieu le 20 mai), la survie jusqu'en nymphe est de 93% contre 74% de survie totale; avec des pousses récoltées 52 jours après le débourrement (11 juillet) les taux de survie sont respectivement 7% et 1.4%; avec des pousses récoltées 146 jours après le débourrement (13 octobre) les survies sont 71% et 50%. Des pousses récoltées 28 jours ou plus après le débourrement, retardent la date de nymphose de 25% par rapport à celles récoltées entre 7 et 14 après le débourrement; parallèlement, elles abaissent l'efficacité de l'assimilation de 39%, l'efficacité de conversion de la biomasse de 125%, et le poids des papillons de 54%. Ces changements sont liés à une diminution de la teneur en azote des pousses de 2.1% à environ 1% du poids sec. Cependant la corrélation entre la survie des chenilles et la teneur en azote n'est pas rigoureuse et un facteur encore inconnu est supposé responsable de l'augmentation de la mortalité quand les chenilles consomment (dans leur régime) des pousses récoltées début juillet, 52 jours après le débourrement. Les travaux destinés à identifier ce facteur inconnu sont en cours.
    Notes: Abstract Diets prepared from lyophilized and powdered current-year (1983) shoots of white spruce Picea glauca (Moench) Voss were offered to 6th-instar larvae of spruce budworm, Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae). With increasing age of current-year shoots, time to pupation increased whereas survival, assimilation efficiency, efficiency of conversion of diet to moth biomass, and moth dry weight generally decreased. Sex of the larvae influenced amount ingested, time to pupation, and subsequent moth weight but not survival, assimilation efficiency, and efficiency of conversion of diet to moth biomass.
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    Entomologia experimentalis et applicata 43 (1987), S. 295-297 
    ISSN: 1570-7458
    Keywords: Oviposition stimulants ; Panolis flammea ; Lepidoptera ; Noctuidae ; Pinus contorta
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    Entomologia experimentalis et applicata 51 (1989), S. 1-4 
    ISSN: 1570-7458
    Keywords: preference ; induction ; feeding ; Papilio demoleus ; Lepidoptera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé La prise de nourriture par des chenilles néonates de P. demoleus est aussi élevée sur régime avec agents de conservation qu'en leur absence, bien qu'elle soit inférieure à celle qui est observée sur les feuilles de son hôte Citrus limettioides. Cependant, quand les chenilles ont été élevées jusqu'au 5ème stade sur des feuilles de C. limettioides, ou sur des régimes avec ou sans conservateurs, leur prise de nourriture sur feuilles de C. limettioides, et régime sans conservateur est aussi importante. Toutes les chenilles élevées sur régime avec conservateur ont consommé lorsqu'elles avaient été maintenues sur le même régime. Par contre, leurs réactions face à un régime contenant des conservateurs a entraîné une diminution de près de 20% après élevage sur un régime sans conservateur, et de près de 90% après élevage sur feuilles de C. limettioides. Les chenilles semblent manifester de l'aversion envers les conservteurs si elles ont été élevées en leur absence, aversion renforcée lorsqu'il y avait eu préalablement alimentation sur feuilles de C. limettioides.
    Notes: Abstract The feeding responses of newly hatched larvae of Papilio demoleus on the diet with preservatives were as high as on the diet without preservatives though less than those on the host lime leaves. However, when the larvae were reared upto the 5th instar on the host lime leaves or the diet with or without preservatives, their feeding responses towards host lime leaves and the diet without preservatives were equally high. The diet with preservatives reared larvae showed 100% response when tested on the same diet. But their response towards diet with preservatives declined to 80% when the larvae were reared on the diet without preservatives and to 10% when they were reared on the host lime leaves. The larvae seem to have an aversion against the preservatives if reared in their absence which was enhanced by their experience of feeding on the host leaves during their ontogeny.
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    Entomologia experimentalis et applicata 48 (1988), S. 293-300 
    ISSN: 1570-7458
    Keywords: Lepidoptera ; Noctuidae ; Heliothis zea ; Hymenoptera ; Trichogrammatidae ; Trichogramma pretiosum ; egg parasitoid ; sex pheromone ; kairomone ; host-community location ; olfactometer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Des expériences menées en olfactométrie avec le parasite oophage Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) et son hôte, Heliothis zea (Boddie) (Lepidoptera: Noctuidae) donnent les résultats suivants. La présence de la phéromone sexuelle de l'hôte réduit de façon significative le nombre de passages entre les champs odorisés. De mème, les parasites visitent plus fréquemment le champ qui dispense l'odeur de la femelle en appel que le champ témoin placé à l'opposé. Par ailleurs, le temps passé dans le champ qui contient la phéromone sexuelle émise par les femelles vierges en appel est significativement supérieur à la durée de visite des champs témoins. Si l'on utilise comme source d'odeur des femelles vierges qui ne sont pas en appel, la réponse est inversée, les parasites sont alors repoussés par l'odeur de ces papillons et le nombre de visites est distribué de façon aléatoire entre les quatre champs. Ces résultats sont discutés dans le contexte de l'écologie du comportement de recherche chez les parasites oophages.
    Notes: Abstract This paper presents results of olfactometer experiments with the egg parasitoid Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) and its host the corn earworm moth, Heliothis zea (Boddie) (Lepidoptera: Noctuidae). The sex pheromone of the host significantly reduced the total number of border crossings between odour fields in the olfactometer. Also, female parasitoids made significantly more visits to the calling moth odour field than to the opposite control field in the olfactometer. Further, the wasps spent significantly more time in the olfactometer field containing the sex pheromone released by calling virgin moths, than in control fields. If non-calling virgin moths were used as odour source, the response was reversed and wasps were repelled by the odour of the moths, and the numbers of visits were evenly distributed over the four flow fields. These results are discussed in the context of foraging ecology of egg parasitoids.
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  • 91
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    Entomologia experimentalis et applicata 40 (1986), S. 71-79 
    ISSN: 1570-7458
    Keywords: oviposition deterrent ; contact chemoreceptors ; electrophysiology ; tarsi ; ovipositor ; Pieris brassicae ; Lepidoptera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Une technique d'enregistrement apical a été utilisée pour examiner la perception d'une phéromone dissuadant la ponte par les poils récepteurs chimiques de contact des femelles de Pieris brassicae. Les réponses électrophysiologiques des poils gustatifs des tarses en présence de solutions de rinçage d'oeufs présentent une fréquence marquée des potentiels d'action provenant principalement d'une cellule sensorielle. Ceci suggère que les poils gustatifs des tarses des pattes antérieures des femelles possèdent, en plus de cellules répondant aux glucosinolates, des cellules sensorielles sensibles spécialement à la phéromone dissuadant la ponte. Des études morphologiques au microscope à balayage révèlent que l'oviposition de P. brassicae est pourvu de deux groupes de chimiorécepteurs de contact. Des enregistrements électrophysiologiques de ces sensilles révèlent la présence d'au moins trois cellules sensorielles, l'une d'entre elles étant un mécanorécepteur. La stimulation avec la solution de rinçage des oeufs évoque un léger accroissement de la fréquence des potentiels d'action qui ne peut être attribué à une cellule sensorielle particulière. Ceci indique que les poils gustatifs abdominaux peuvent participer d'une certaine façon à la perception de la phéromone dissuadant la ponte. Les réponses aux glucosinolates ne diffèrent pas significativement des stimulations témoin.
    Notes: Abstract Perception of the oviposition deterring pheromone by contact chemoreceptors in female Pieris brassicae was studied employing a tip recording technique. Electrophysiological responses of tarsal taste hairs to eggwash solutions show a marked increase in frequency of spikes originating from only one sensory cell. This suggests that in foretarsal taste hairs females, apart from the glucosinolate cells also possess sense cells specifically sensitive to the oviposition deterring pheromone. Morphological studies by means of the scanning electron microscope revealed that the ovipositor of P. brassicae is provided with two groups of contact chemoreceptors. Electrophysiological recordings from these sensilla indicate the presence of at least three sensory cells, one of them being a mechanoreceptor. Stimulation with eggwash evokes a slight increase in spike frequency which cannot be ascribed to one particular sense cell. This indicates that abdominal taste hairs in some way may participate in the perception of the oviposition deterring pheromone. Responses to glucosinolates do not differ significantly from control stimulations.
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  • 92
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    Entomologia experimentalis et applicata 46 (1988), S. 93-100 
    ISSN: 1570-7458
    Keywords: antifeedants ; aristolochic acid ; armyworm ; feeding ; desensitization ; Lepidoptera ; Noctuidae ; Spodoptera frugiperda
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé L'avenir des phagodissuadants en protection des cultures dépend, en particulier, de l'aptitude des insectes à devenir insensibles à ces substances. Les phagodissuadants sont classés en relatifs ou absolus, suivant que les insectes consomment les tissus traités ou se laissent mourir de faim. Cette propriété dépend beaucoup de la structure chimique, mais les paramètres biologiques n'ont pas été étudiés à fond. Des expériences ont donc été entreprises pour apprécier les effets combinés de jeûne et d'autres facteurs physiologiques dans l'apparition et l'évolution de la désensibilisation chez une espèce polyphage: Spodoptera frugiperda (Lep. Noctuidae). Des expériences préliminaires ont montré qu'un alcaloïde, l'acide aristolochique, est un puissant phagodissuadant pour S. frugiperda. Les chenilles, réparties en deux groupes expérimentaux, ont toutes été isolées et ont reçu chacune deux feuilles de Phaseolus lunatus: une témoin et une traitée avec 1000 ppm. Dans le groupe 1), les feuilles étaient remplacées dès consommation; dans le groupe 2), elles ne l'étaient pas. Un puissant effet dissuadant a été observé tout au long de l'expérience pour le groupe 1); dans le groupe 2), les chenilles ont finalement consommé les feuilles traitées. L'apparition de la désensibilisation était liée au jeûne. Quelques individus ont commencé à s'alimenter sur la rondelle traitée 3,5 heures aprés avoir totalement consommé la rondelle témoin; le temps médian du début de cette consommation a été de 5,7 h. Une fois la répulsion surmontée, les chenilles ont consommé le feuillage traité de la même façon que le feuillage témoin. Les expériences ont été recommencées avec les mêmes insectes, mais sans que les feuilles témoins aient alors été remplacées dans aucun des 2 groupes. Dans cette seconde expérience, les chenilles, qui avaient précédemment consommé des feuilles traitées, sont à nouveau dissuadées lors de choix binaires; cependant elles ont mangé plus rapidement les feuilles traitées, que ne l'ont fait les chenilles qui avaient disposé d'une source inépuisable de feuilles témoins. Elles se sont alimentées aussi plus facilement et plus généralement au cours de cette seconde expérience qu'au cours de la première. Quoi qu'il en soit, les deux groupes ont présenté finalement une désensibilisation. Un modèle mathématique général est proposé pour évaluer l'apparition et l'évolution de la désensibilisation. Les possibilités d'utilisation des phagodissuadants dans la protection des cultures sont discutées à la lumière de ces résultats.
    Notes: Abstract Fall armyworm larvae, Spodoptera frugiperda (J. G. Smith), were exposed to leaf disks treated with the feeding deterrent aristolochic acid under two types of regimes: In group 1, untreated leaf tissue was replenished as soon as it was consumed; in group 2, the control tissue was not replenished. A strong feeding deterrence was evident during the early stages of the assay in both groups, but eventually declined in group 2. When the experiment was continued through a second 24 h period, the control tissue was not replenished for either group. During this second trial, group 2 larvae, which had previously fed on treated tissue, fed more rapidly on treated tissue than did group 1 larvae. Moreover, group 2 larvae fed more readily and extensively on treated tissue than they had in the first trial. The time for the onset of behavioral desensitization was determined by subtracting the median onset of feeding on untreated tissue from the median interval between when a larva finished all of the control tissue and when it started feeding on treated tissue under no-choice conditions. Once larvae began to feed on treated tissue, their rate of consumption was equal to that of larvae feeding on control tissue. A general model for determining the onset and degree of desensitization was developed. The implications of these results for future experiments aimed at determining the underlying physiological mechanisms and the use of antifeedants in plant protection are discussed.
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  • 93
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    Entomologia experimentalis et applicata 42 (1986), S. 109-117 
    ISSN: 1570-7458
    Keywords: cabbage looper ; Trichoplusia ni ; Glycine max ; soybeans ; trichomes ; plant resistance ; Noctuidae ; Lepidoptera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé L'influence de la densité et de la longueur des trichomes de Glycine max sur la résistance à Trichoplusia ni a été évaluée suivant la position des feuilles sur une lignée résistante (‘PI 227687’) et sur un cultivar sensible (‘Davis’). Les feuilles apicales (juvéniles) tant de PI 227687 que de Davis, recouvertes de trichomes denses, résistèrent mieux à l'alimentation larvaire et à la survie de T. ni. Quand ces trichomes étaient éliminés, ces feuilles ne résistaient pas plus à l'alimentation des larves de T. ni que les feuilles non rasées TL3 et TL5 de PI 227687 ou toutes les autres feuilles de Davis. Les tests avec des extraits dans l'acétate d'éthyle et l'hexane de feuilles provenant de différentes positions de PI 227687 et Davis, destinés à mettre en évidence des phagodissuadants, ont montré que la résistance observée chez les feuilles apicales de Davis était attribuable aux trichomes (c'est-à-dire à un caractère morphologique), tandis que chez les mêmes feuilles de PI 227687 elle impliquait à la fois des trichomes (morphologie) et des substances chimiques, mais avec une prédominance de l'influence des trichomes.
    Notes: Abstract Role of leaf trichome density and length in Glycine max (L.) Merr. resistance to Trichoplusia ni (Hübner) was evaluated at different leaf positions on a relatively resistant soybean, plant introduction (PI) 227687, and a relatively susceptible cultivar, ‘Davis’. The uppermost (juvenile) leaf within both PI 227687 and ‘Davis’ plants, which is densely covered with trichomes, was most resistant to T. ni larval feeding and survival. When these trichomes were shaven off, such leaves became as susceptible to T. ni larval feeding as unshaven TL3 and TL5 leaves (PI 227687) or all other unshaven leaves (‘Davis’). Bioassays for antifeedants in ethyl acetate and hexane extractables from leaves at the different positions on PI 227687 and ‘Davis’ plants showed that the resistance observed in the uppermost ‘Davis’ leaf is attributable to trichomes (i.e., a morphological factor); whereas, in the uppermost PI 227687 leaf it involves both morphological (trichomes) and chemical factors, but the trichome parameter is dominant.
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    Entomologia experimentalis et applicata 46 (1988), S. 149-153 
    ISSN: 1570-7458
    Keywords: Lepidoptera ; Pyralidae ; Chilo partellus maize ; resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé L'étude a porté sur la croissance et la production avec différents niveaux de minage des tiges de 4 cultivars de maïs, lors de divers degrés de contamination artificielle par des chenilles de C. partellus. Le cultivar sensible ‘Inbred A’ souffre plus des mines de C. partellus que ICZ1-CM, ICZ2-CM et Katumani composite B. Les mines influent significativement sur la croissance des 4 cultivars. Il y a une corrélation négative significative entre le minage des tiges et la production pour les cultivars ‘Inbred A’ et Katumani composite B, mais la relation n'est pas significative pour ICZ1-CM et ICZ2-CM. Les différences entre le minage des tiges et la récolte des 4 cultivars sont dues aux différents degrés de minage des tiges de ces cultivars par C. partellus.
    Notes: Abstract The effects of different degrees of stem tunneling caused by different levels of artificial infestation by the larvae of Chilo partellus (Swinhoe) on growth and yield of 4 maize cultivars were studied. The susceptible ‘Inbred A’ suffered much more tunneling than ICZ1-CM, ICZ2-CM and Katumani Composite B. This tunneling influenced significantly the plant growth of all the four cultivars. There was a significant negative correlation between tunneling and yield for the cultivars ‘Inbred A’ and Katumani Composite B, but such a relationship was not significant for ICZ1-CM and ICZ2-CM. Such differences in the relationships between tunneling and yield among the 4 cultivars are due to different degrees of tunneling caused by C. partellus larvae to the plants of these cultivars.
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  • 95
    ISSN: 1570-7458
    Keywords: (Z)-11-hexadecenyl acetate ; (Z)-11-hexadecenal ; (Z)-11-hexadecenol ; (Z)-9-tetradecenyl acetate ; hexadecanyl acetate ; Mamestra suasa ; Lepidoptera ; Noctuidae ; sex pheromone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé On a trouvé l'acetoxy-1 hexadécene-11 Z (Z-11-16:Ac), le hexadécene-11 Z al-1 (Z-11-16:Ald), le hexadécene-11 Z ol-1 (Z-11-16:OH) et l'acetoxy-1 hexadécene (16:Ac) dans des extraits de glandes phéromona les des femelles deMamestra suasa. La proportion relative des composés était 100/2/10/5. Tous les quatre composés ont été présents aussi dans les collections d'émanations des femelles en stade d'appel, dans la proportion un peu différente de 100/7/5/5. On n'a détecté aucune trace des tétradécenes al-1 ou d'acetoxy-1 tétradécenes. On a démontré la présence de hexadécenoate-1 methyl, hexadécene-9 Z oate-1 methyl et héxadécene-11 Z oate-1 methyl dans des extraits des glandes, par la méthode de ‘base methanolysis’. On n'a trouvé pas des tétradéceneoates methyl. En éléctroantennographie, Z-11-16:Ac a donné les meilleurs réponses, suivis par l'acetoxy-1 tétradécene-9 Z (Z-9-14:Ac), Z-11-16:Ald et Z-11-16:OH. Dans des études de ‘single sensillum’ les cellules à amplitude grande ont répondu à la stimulation avec de Z-11-16:Ac, cependant les cellules à amplitude petite ont répondu à la stimulation avec des deux composés Z-9-14:Ac et Z-11-16:OH. On a trouvé des cellules sensitives à Z-11-16:Ald dans 1 entre 60 sensilla étudiés. À la chambre de vol, le dose de 0.1 μg d'un mélange de 10:1 de Z-11-16:Ac/Z-11-16:Ald a provoqué les mêmes réponses et à l'intensité pareille comme 3 glandes phéromonales isolées des femelles. En piégeages sur le champs des males en quantité importante ont été capturé par un mélange de 10:1 de Z-11-16:Ac/Z-11-15:Ald en Bulgarie et Hongrie. L'addition de 16:Ac au mélange binaire n'avait aucun effet, cependant l'addition de plus de 1% de Z-11-16:OH ou 0.1% de Z-9-14:Ac a sérieusement diminué les captûres. En comparant des proportions différentes du mélange de l'acetoxy/aldéhyde dans des doses différentes, on a observé les meilleurs captûres avec de la proportion 10:1 et à la dose la plus haute (1 000 μg).
    Notes: Abstract (Z)-11-hexadecenyl acetate (Z-11-16:Ac), (Z)-11-hexadecenal (Z-11-16:Ald), (Z)-11-hexadecenol (Z-11-16:OH) and hexadecanyl acetate (16:Ac) were found in pheromone gland extracts of femaleMamestra suasa (Den. et Schiff.) in the relative amounts 100/2/10/5. All four compounds were also present in collections of aiiborne volatiles from calling females in a 100/7/5/5 ratio. No traces of 14 carbon aldehydes or acetates were detected. In gland extracts the presence of methyl hexadecanoate methyl (Z)-9-hexadecenoate and methyl (Z)-11-hexadecenoate was demonstrated by base methanolysis. No methyl tetradecenoates were detected. In EAG tests Z-11-16:Ac gave the best responses, followed by (Z)-9-tetradecenyl acetate (Z-9-14:Ac) Z-11-16:Ald and Z-11-16:OH. In single sensillum recordings large spike amplitude cells in sensilla responded to Z-11-16:Ac, while small spike amplitude cells to both Z-11-16:OH and Z-9-14:Ac. Cells responding to Z-11-16:Ald were found in one out of 60 sensilla tested. In wind tunnel tests 0.1 μg of a 10:1 blend of Z-11-16:Ac/Z-11-16:Ald evoked the same responses and at a similar intensity as 3 isolated female pheromone glands did. In field tests a 10:1 blend of Z-11-16:Ac/Z-11-16:Ald caught significant numbers of males in both Bulgaria and Hungary. The addition of 16:Ac to the binary blend did not have any effect, while more than 1% of Z-11-16:OH or 0.1% of Z-9-14:Ac dramatically decreased captures. In comparing different ratios of the, acetate/aldehyde blend at different dose levels, best catches were recorded at the 10:1 ratio and at the highest (1000 μg) dose level.
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    Entomologia experimentalis et applicata 43 (1987), S. 271-274 
    ISSN: 1570-7458
    Keywords: Southwestern corn borer ; Diatraea grandiosella ; Lepidoptera ; insects and fertilizer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Nous avons étudié les corrélations entre l'utilisation d'engrais azotés et phosphatés d'une part, l'infestation et l'alimentation de D. grandiosella sur maïs en champs d'autre part. Les formules d'engrais comparées étaient: pas d'engrais, 90 et 179 kg N/ha sans P, 45 et 90 kg P/ha sans N, et les combinaisons de ces deux teneurs en N et P. La contamination était plus élevée dans les lots ayant reçu de l'azote que dans ceux traités sans N, mais la présence d'azote n'a pas réduit le décapage des tiges et la verse dus à l'alimentatin larvaire. A l'inverse, les lots n'ayant reçu que du phosphore avaient des pourcentages plus faibles de tiges contaminées par D. grandiosella et ainsi décapées et versées, que ceux qui n'avaient pas reçu P. Il n'a pas eu de différences significatives dans les contaminations ou les dégats entre les lots ayant reçu différentes combinaisons de N et P, et les effets de ces combinaisons sur l'insecte étaient intermédiaires à ceux de N et P seuls.
    Notes: Abstract Nitrogen (N) and phosphorus (P) fertilizers have differing effects on southwestern corn borer (SWCB). Diatraea grandiosella Dyar, densities and damage to field corn, Zea mays L. Nitrogen fertilization of corn is associated with an increase in number of stalks infested and girdled by corn borers, while addition of P has the opposite effect. When combinations of N and P were applied, there were no significant differences in SWCB infestation or damage from plots receiving no fertilizer. The effect of combinations of N and P on SWCB were intermediate to either element alone.
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  • 97
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    Entomologia experimentalis et applicata 50 (1989), S. 141-147 
    ISSN: 1570-7458
    Keywords: Heliothis zea ; Noctuidae ; Lepidoptera ; Eucelatoria bryani ; Tachinidae ; Diptera ; host-parasitoid relationship ; host suitability ; progeny production
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les influences de l'état de développement de l'hôte sur le taux de parasitisme, la production de descendants, l'émergence des adultes et le taux sexuel de la techinaire E. bryani Sabrosky ont été examinés au laboratoire. Un parasitisme réussi,-qui entraîne la formation d'un parasitoïde adulte-, s'effectue dans les chenilles de stades 2 à 5 et dans les prénymphes d'Heliothis zea Boddie. II s'agit d'un élargissement considérable de la gamme connue des tailles convenables d'hôtes. Bien que le parasitisme n'ait jamais réussi avec les chenilles de premier stade, une très forte mortalité, 93% a été observée quand ces petites chenilles ont été exposées à la tachinaire. Pour permettre l'introduction par le larvipositeur des asticots dans la chenille, la mouche perfore la cuticule de l'hôte avec un sclérite modifié; ainsi, une grande partie de la mortalité est provoquée vraisemblablement par le traumatisme dû au parasitoïde. Le succès du parasitisme a augmenté en fonction du développement de l'hôte du second stade (30%) au cinquième stade (95%), pour tomber à 63% dans les prénymphes. Cependant, aucune des prénymphes exposées aux mouches n'a été capable de donner des papillons. Les production moyennes de pupes et de mouches par chenille effectivement parasitée ont augmenté avec le stade de développement de l'hôte pouratteindre dans les prénymphes respectivement 14,5±1,33 et 10,6±1,02. Le taux sexuel des mouches obtenues a été très variable pour les différents stades de développement des chenilles, sans qu'aucune corrélation ait pu être mise en évidence. Une formule permettant de calculer un ‘indice d'adéquation de l'hôte’ est proposé. Cet indice permet une comparaison directe des impacts globaux et des potentiels reproducteurs des femelles de E. bryani attaquant des hôtes à différents stades.
    Notes: Abstract Eucelatoria bryani Sabrosky (Diptera: Tachinidae) successfully parasitized 2nd through 5th instars and prepupal Heliothis zea (Boddie) (Lepidoptera: Noctuidae) in the laboratory. Percent successful parasitism (that which resulted in the production of adult parasitoid progeny) increased with host developmental state, reaching 95% in 5th instars, but fell to 63% in prepupae. While 25% of the exposed prepupae metamorphosed to pupae, none developed into adults. E. bryani maggots emerged from only 5% of H. zea pupae. The mean number of fly puparia and adults produced per successfully parasitized larva increased with host stadium, reaching 14.5±1.33 (SEM) and 10.6±1.02, respectively, in prepupae. The sex ratio of adult parasitoid progeny per host larval stadium was variable, and did not appear to follow a pattern. A formula for calculating a ‘host favorability index’ is presented. This index allows a direct comparison of the overall impact and reproductive potential of E. bryani attacking hosts of varying developmental states.
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    Entomologia experimentalis et applicata 47 (1988), S. 289-295 
    ISSN: 1570-7458
    Keywords: competition ; multiparasitization ; parasitoid ; physical attack ; Trieces tricarinatus ; Triclistus yponomeutae ; Hymenoptera ; Ichneumonidae ; Yponomeuta vigintipunctatus ; Lepidoptera ; Yponomeutidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé La compétition entre les deux ichneumonides endoparasitoïdes solitaires Trieces tricarinatus Grav. et Triclistus yponomeutae Aeschl. a été examinée en élevant et disséquant des Yponomeuta vigintipunctatus Retz. attaqués le même jour par les deux parasitoïdes. Les résultats des dissections des hôtes multiattaqués ont été comparés à ceux des hôtes attaqués par un seul parasite, pour séparer la mortalité ou l'absence de parasitoïde provoquées par la compétition à celles dues à d'autres facteurs. On a constaté qu'un seul parasite était capable d'achever son développement. Dès que l'hôte était nymphosé et que les deux parasitoïdes étaient au premier stade larvaire, une des larves tuait sa compétitrice. Pour une fraction importante des larves éliminées, il a été possible de montrer qu'elles avaient été tuées par une aggression physique, pour les autres ce mode d'élimination était vraisemblable. L'espèce de parasitoïde qui survit dépend du nombre de jours entre la ponte des ichneumonides et la nymphose de l'hôte. Ce délai détermine le degré de développment des parasitoïdes et le moment réel de la compétition. Probablement, T. tricarinatus est le seul à survivre lorsque la nymphose de l'hôte a lieu avant l'éclosion des oeufs de T. yponomeutae.
    Notes: Abstract Competition between the solitary endoparasitoids Trieces tricarinatus (Gravenhorst) and Triclistus yponomeutae Aeschlimann (Hymenoptera: Ichneumonidae) results in the survival of one or the other of them. Once the host, Yponomeuta vigintipunctatus (Retzius) (Lepidoptera: Yponomeutidae) has pupated and both parasitoids have completed their development to first instar larvae, one of the parasitoid larvae kills the other. Which of the parasitoids survives depends on the number of days between parasitization and pupation. As a result of their type of development, this period determines the extent of development of the parasitoids at the moment of actual competition. Apparently, T. tricarinatus survives only if pupation of the host occurs before egg hatching of T. yponomeutae.
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    Colloid & polymer science 260 (1982), S. 564-569 
    ISSN: 1435-1536
    Keywords: lin. Polyethylene ; Single crystals ; Heat of Fusion ; DSC ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Recently published results for solution crystallized PE single crystals have shown, that the experimental heat of fusionΔH * is higher, if the solvent is exchanged to silicon oil (oil suspension samples) as compared with dried mats. This has been interpreted by the collapse of the original hollow pyramids during drying, inducing lateral defects within the lamellae. The present investigation does not confirm this unexpected result.ΔH * of dried mats (T c 66 to 91 °C) and of the corresponding oil suspension samples agree within the rather small limits of experimental error. The crystallinities as derived fromΔH *, density or WAXS are in excellent agreement. SEM micrographs of cold fractured dried mats show their spongy macromorphology, but TEM micrographs of stained ultra-thin sections reveal the lamellar morphology of the walls, consisting of curved lamellae and stacked hollow pyramides. If a dried mat is sintered at room temperature, a dense transparent film is obtained with a rather regular stacked morphology of large flat lamellae.ΔH * of these films agrees with that of the original mat.
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    Colloid & polymer science 261 (1983), S. 373-374 
    ISSN: 1435-1536
    Keywords: Electron microscopy ; short-time staining ; nodular structure ; crystallization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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