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  • CR: 5.17
  • Lepidoptera
  • Ultrastructure
  • Springer  (58)
  • Birkhäuser
  • Division of Earthsciences, Seismological Laboratory, California Institute of Technology
  • Dover Publ.
  • North-Holland
  • 2010-2014
  • 1995-1999  (58)
  • 1980-1984
  • 1950-1954
  • 1996  (58)
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  • Springer  (58)
  • Birkhäuser
  • Division of Earthsciences, Seismological Laboratory, California Institute of Technology
  • Dover Publ.
  • North-Holland
  • +
Years
  • 2010-2014
  • 1995-1999  (58)
  • 1980-1984
  • 1950-1954
Year
  • 1
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    Entomologia experimentalis et applicata 80 (1996), S. 145-148 
    ISSN: 1570-7458
    Keywords: fruit-piercing moths ; Pacific biotypes ; Lepidoptera ; Noctuidae ; Fabaceae ; Menispermaceae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
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  • 2
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    Entomologia experimentalis et applicata 80 (1996), S. 149-151 
    ISSN: 1570-7458
    Keywords: Lepidoptera ; Satyridae ; wing pattern induction ; food plant quality
    Source: Springer Online Journal Archives 1860-2000
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  • 3
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    Entomologia experimentalis et applicata 80 (1996), S. 152-155 
    ISSN: 1570-7458
    Keywords: predispersal seed predator guild ; Leguminosae ; Bruchidae ; Curculionidae ; Lepidoptera ; intra-and interspecific competition ; Monte Carlo simulation
    Source: Springer Online Journal Archives 1860-2000
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  • 4
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    Entomologia experimentalis et applicata 79 (1996), S. 51-59 
    ISSN: 1570-7458
    Keywords: Lepidoptera ; Tortricidae ; mating disruption ; pest control ; multiple sources ; attraction ; arrestment ; interruption ; range ; (Z)-8-dodecenyl acetate ; (E)-8-dodecenyl acetate ; (Z)-8-dodecanol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The behaviour of Grapholita molesta (Busck) (Lepidoptera: Tortricidae) males was studied in overlapping sex pheromone plumes in a wind tunnel. The ultimate aim of the study was to assess the effect of different treatments on male behaviour and consider the observed changes within the context of the suggested mechanisms underlying mating disruption. Two baits were placed either in series or parallel using both synthetic pheromone blends and female extracts. One bait, the reference containing (Z)-8-dodecenyl acetate/(E)-8-dodecenyl acetate/(Z)-8-dodecenol in a ratio of 100/6/10 was kept constant at a dose of 100 μg of the main component, giving a composition and a release rate close to that of a female. The dose of the other bait varied between 0.1 and 100 times the concentration of the reference and was a mixture of one, two or three pheromone components. Males clearly discriminated between different blends and doses in the overlapping plumes, for regardless if the lures were presented in series or in parallel they followed the complete plume. Complete suppression of the response to the reference was only achieved with 300 μg of the optimal three-component blend on the other lure. When tested singly, a bait consisting of Z8-12:OAc/E8-12:OAc/Z8-12:O Hin a 100/0.2/0.4 ratio, attracted a high proportion of the males when placed 75 cm upwind of the male release site, but no males from 150 cm. Our data suggest that complete pheromone blends should be more effective than any incomplete blends in mating disruption formulations for G. molesta.
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  • 5
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    Entomologia experimentalis et applicata 79 (1996), S. 195-202 
    ISSN: 1570-7458
    Keywords: antifeedant ; drimane ; feeding behaviour ; sensory response ; structure-activity relationship ; neural code ; Pieris brassicae ; Lepidoptera ; Pieridae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Fifteen drimane compounds were tested for their feeding inhibiting activity in larvae of Pieris brassicae L. (Lepidoptera: Pieridae) when applied to leaf material of the host plant Brassica oleracea L. The antifeedant efficacy of the drimanes was related to their molecular structure in order to identify important functional groups. Of the drimanes tested, those with a lactone group on the B-ring were the most effective feeding inhibitors. Additionally, the sensory responses to 13 of the drimanes were measured. Neural activity was evoked in the deterrent cell in the medial sensillum styloconicum. Also, inhibition of sensory responses to feeding stimulants was found. Results of behavioural and electrophysiological tests were correlated in an attempt to elucidate the sensory code underlying feeding inhibition by drimanes in Pieris brassicae. It was concluded that the response of the deterrent cell in the medial sensillum styloconicum contributes significantly to inhibition of feeding behaviour in larvae of Pieris brassicae.
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  • 6
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    Entomologia experimentalis et applicata 79 (1996), S. 227-234 
    ISSN: 1570-7458
    Keywords: Helicoverpa zea ; Lepidoptera ; Noctuidae ; Eucelatoria bryani ; Eucelatoria rubentis ; Diptera ; Tachinidae ; parasitoid competition ; host discrimination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Multiple parasitism of Helicoverpa zea (Lepidoptera: Noctuidae) had differential effects on the gregarious endoparasitoids Eucelatoria bryani and E. rubentis (Diptera: Tachinidae). Both species were able to survive in multiparasitized hosts. However while the survival of E. bryani was not affected by the presence of E. rubentis, E. rubentis survival was reduced when competing with 24-h older E. bryani. The presence of E. rubentis did not result in a decrease in the size of E. bryani except when E. rubentis was 24-h older than E. bryani. The presence of E. bryani tended to result in smaller E. rubentis. The presence of similarly aged heterospecific competitors often resulted in prolonged development time for both species. Naïve females did not alter oviposition between unparasitized and heterospecifically parasitized fifth-instar larvae of H. zea, either by ovipositing less frequently in parasitized hosts than unparasitized ones, or by reducing clutch size in parasitized hosts. These results indicate that in H. zea, E. bryani is a superior competitor compared with E. rubentis. These factors should be considered in evaluating the potential of E. bryani and E. rubentis as biological control agents of H. zea.
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  • 7
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    Entomologia experimentalis et applicata 80 (1996), S. 15-18 
    ISSN: 1570-7458
    Keywords: pheromone-binding protein ; general odorant-binding protein ; sensillum trichodeum ; sensillum basiconicum ; Lepidoptera ; immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
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  • 8
    ISSN: 1570-7458
    Keywords: insect ; parasitoid ; protein ; free amino acid ; cadmiun ; lead ; copper ; zinc ; Lepidoptera ; Hymenoptera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Heavy metal contamination of the forest pest insect Lymantria dispar (L.) (Lepidoptera; Lymantriidae), the gypsy moth, can alter its haemolymph composition, as has already been shown for carbohydrates and lipids in recent studies. L. dispar larvae are frequently parasitized by Glyptapanteles liparidis (Bouché) (Hymenoptera; Braconidae) larvae, which can—to some extent—regulate the population size of the pest insect. The parasitoids feed on the haemolymph of L. dispar larvae; hence, a different haemolymph composition of the host alters the trophic situation of the parasitoids. The aim of the present study was to investigate whether metal contamination also affects the concentrations of free amino acids in L. dispar haemolymph, and protein concentrations in their haemolymph and tissue. L. dispar larvae were parasitized on the first day of the second instar and then reared on diets contaminated with Cd, Pb, Cu or Zn at two concentrations each. Haemolymph and total body tissue of the larvae (fourth instar/third day) were analyzed. The concentrations of the free amino acids were elevated in five out of the eight contamination groups (Cd6, Pb4, Cu6, Cu10, Zn60), whereas haemolymph protein concentrations were significantly reduced in all contaminated individuals. The haemolymph protein concentration was 18 mg/ml in the control group and decreased to less than 10 mg/ml due to cadmium and zinc contamination at both concentrations and in the low copper contamination group. In contrast, total body proteins (136 μg/mg dry weight in the control group) were elevated due to heavy metal stress. Analyses of haemolymph protein concentrations during the fourth instar demonstrated an increase of the proteins from day one to day four (followed by a decrease on the fifth day) in the control group and the cadmium contamination group. A steady increase of proteins from the first to the fifth day in the copper and zinc contaminated larvae indicated a retarded development in these groups. Thus, the present study along with other recent studies demonstrated, that heavy metal stress changes the concentrations of all main haemolymph compounds of L. dispar larvae.
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  • 9
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    Entomologia experimentalis et applicata 81 (1996), S. 307-313 
    ISSN: 1570-7458
    Keywords: feeding deterrents ; desensitization ; habituation ; azadirachtin ; neem ; Spodoptera litura ; Lepidoptera ; Noctuidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The deterrence of azadirachtin, in its pure form and as a constituent of neem seed extract, to fifth instar Spodoptera litura (Fab.) larvae, was measured using cabbage, Brassica oleraceae (L.) var. capitata, leaf disc assays. Paired-choice assays, in which larvae could choose between feeding on a treated (1.3 ng azadirachtin per square cm leaf area) or an untreated leaf disc for 2 h, were conducted at 24 h intervals throughout the fifth instar. In addition, no-choice assays, in which larvae could feed on only one leaf disc (10 ng azadirachtin per square cm leaf area) for 1.5 h, were conducted consecutively over a six hour period at the beginning of the fifth instar. The effects of hunger and habituation on desensitization in our no-choice tests were partitioned. After repeated exposures, larvae became desensitized to pure azadirachtinal in both choice and no-choice tests, but did not desensitize to neem containing the same absolute amount of azadirachtin in choice tests. Hunger was responsible for approximately one third of the desensitization response in the no-choice tests. Sensitivity to azadirachtin was independent of age within the fifth instar.
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  • 10
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    Entomologia experimentalis et applicata 78 (1996), S. 1-8 
    ISSN: 1570-7458
    Keywords: induction ; imprinting ; learning ; caterpillar ; Lepidoptera ; experience ; diet breadth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This review discusses the ambiguity of results obtained from dual-choice feeding tests, especially in relation to the study of effects of experience. Induced preference experiments done this way can be caused by up to nine potential changes in caterpillar behavior. In addition different physiological mechanisms that could lead to the process of induced preference are discussed. These include habituation to deterrents, the increased ability to process xenobiotics, the acquisition of specific positive responses, sensitization, and associative learning. These different processes might relate to function in different ways so that distinguishing them is important to progress in understanding the phenomenon. Suggestions for experimental designs that provide details on processes involved are indicated.
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  • 11
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    Entomologia experimentalis et applicata 80 (1996), S. 120-123 
    ISSN: 1570-7458
    Keywords: electroantennography ; Lepidoptera ; plant odours ; Ostrinia nubilalis
    Source: Springer Online Journal Archives 1860-2000
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  • 12
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    Entomologia experimentalis et applicata 80 (1996), S. 289-292 
    ISSN: 1570-7458
    Keywords: tri-trophic interactions ; demography ; diamondback moth ; Plutella xylostella ; Lepidoptera ; Plutellidae ; Diadegma insulare ; Hymenoptera ; Ichneumonidae ; cabbage looper ; Trichoplusia ; Noctuidae ; Patrocloides montanus ; Cruciferae ; Brassica oleracea ; B. nigra ; fertilization ; sex ratio
    Source: Springer Online Journal Archives 1860-2000
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  • 13
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    Entomologia experimentalis et applicata 80 (1996), S. 315-319 
    ISSN: 1570-7458
    Keywords: phylogeny ; host shift ; climate ; abiotic thermal constraints ; leaf quality ; phenology ; larval growth ; oviposition preference ; Lepidoptera
    Source: Springer Online Journal Archives 1860-2000
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  • 14
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    Entomologia experimentalis et applicata 81 (1996), S. 315-323 
    ISSN: 1570-7458
    Keywords: disruption ; pheromone ; mass trapping ; Pectinophora gossypiella ; Lepidoptera ; cotton ; Brazil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Mass Trapping was used to control pink bollworm (PBW), Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae), populations in cotton fields in Brazil. Oil traps containing lures with a high dose of pheromone, installed at a density of 20 traps per ha soon after the occurrence of the first cotton fruits (or bolls), suppressed PBW populations below detection levels using Delta traps and manual examination of 100 green cotton bolls per ha. Pheromone sources of 0,2 g (approximately 150 NoMate® fibers) were effective in attracting PBW male moths to oil traps for at least three weeks. Trap captures showed that PBW males located the high concentration pheromone plumes, oriented upwind, and landed on or inside the traps. The long life of the pheromone sources and the long lasting viscosity of the oil surface ensured low trap maintenance, thus rendering mass trapping viable as an alternative technique for the control of P. gossypiella populations in commercial cotton fields. We discuss probable mechanisms promoting suppression of PBW populations in fields with mass trapping control.
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  • 15
    ISSN: 1420-9071
    Keywords: Mating ; pheromone ; epoxyheneicosadiene ; enantiomer ; Arctiidae ; Callimorpha ; Tyria ; Lepidoptera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract It has been suggested that a common sex pheromone composition may account for interspecific sexual interactions observed with certain moths in the Arctiidae. In this study, it is demonstrated that the sex pheromones released by females of the Scarlet Tiger Moth,Callimorpha dominula L., and the Cinnabar Moth,Tyria jacobaeae L., have similar activities and elute at the same retention time on analysis by coupled gas chromatography (GC)-electrophysiology with males from each species. Peak enhancement on GC, chiral GC and coupled GC-mass spectrometry using authentic compounds show that the sex pheromone for bothC. dominula andT. jacobaeae is (3Z,6Z,9S,10R)-9,10-epoxyheneicosa-3,6-diene.
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  • 16
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    Journal of comparative physiology 178 (1996), S. 55-61 
    ISSN: 1432-1351
    Keywords: Electrophysiology ; Lepidoptera ; Photoreceptor ; Spectral sensitivity ; Vision
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract 1. The ommatidia of the butterfly Papilio have a fused and tiered rhabdom. The distal tier of the rhabdom is made up of four distal photoreceptors (R1–4), whereas the proximal tier is made up of four proximal (R5–8) and one basal photoreceptor cell (R9). 2. We first confirmed by light microscopy that the ommatidia of Papilio are not twisted, i.e. have the same spatial organization all about the longitudinal axis. The polarization method, previously applied to the distal tier, hence is applicable to identify the photoreceptor location from the peak angle of the polarization sensitivity. 3. We determined the polarization and spectral sensitivity of in total 109 proximal and basal photoreceptors in the lateral looking eye region. All of the photoreceptors were either green or red type, most of which fall into three classes as judged by the peak angles of the polarization sensitivity: around 40°, 150°, and 180° (= 0°) with respect to the dorso-ventral axis. The first two classes are formed by the proximal photoreceptors with straight microvilli oriented at the average angle of 39° (R6, 8) and 144° (R5, 7) respectively, and the third is formed by the basal photoreceptors R9 with straight microvilli oriented at 180° (= 0°). The mean polarization sensitivity (PS = maximal sensitivity/minimal sensitivity) was about 2. 4. 75% of the proximal and 48% of the basal photoreceptors were of the red type. 5. A single ommatidium of Papilio appears to contain two to four types of spectral receptors.
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  • 17
    ISSN: 1432-1351
    Keywords: Heliothis ; Noctuidae ; Lepidoptera ; Plume structure ; Behavior
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract 1) Male Heliothis virescens moths flew upwind to pulsed pheromone plumes. Upon truncation of the pulsed plume males flew into clean air, turning their tracks crosswind (〉 60° relative to directly upwind direction at 0°) within an average of 0.27 s, and were casting, perpendicular to the wind-line (90°), within 0.43 s. 2) The characteristic casting flight in clean air consisted of left-right crosswind reversals, continuing for many seconds without further pheromonal stimulation. Males intercepting a single strand of pheromone during casting flight responded by surging upwind (track angles 〈 60°). The phasic surge lasted only 0.38 s before reverting to crosswind flight (〉 60°). 3) Average templates of responses in two and three dimensions were created. Males controlled their vertical deviations very tightly when in contact with pheromone but upon entering clean air, lateral and vertical excursions became much greater. 4) Males failed to sustain upwind flight to repetitively pulsed plumes generated at 〈 4 filaments/s. At the threshold frequency of 4 pulses/s we show that upwind flights were composed of reiterated surges followed by crosswind casting. As the pulse frequency increased, the tracks became straighter and the single filament cast-surge-cast template could be viewed only sporadically when, for example, a male apparently failed to intercept filaments.
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  • 18
    ISSN: 1432-2285
    Keywords: Conifer ; Fluoride ; Nitrogen ; Sulphur dioxide ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Effects of SO2, aqueous fluoride (NaF) and a solution of nitrogen compounds (NH4NO3) on the visible symptoms, pollutant accumulation and ultrastructure of Scots pine (Pinus sylvestris L.) and Norway spruce [Picea abies (L.) Karst.] seedlings were studied in an open-air experiment lasting for 3 consecutive years. Visible injury symptoms were most pronounced in combination exposures and whenever F was applied. Visible symptoms correlated well with needle pollutant concentrations. Exposure to NaF increased needle F contents particularly when F was applied with SO2 or NH4NO3. This suggests that a reduction in N or SO2 emissions, in F polluted areas, could improve the condition of conifers via decreased accumulation of phytotoxic F in the needles. Norway spruce needles accumulated 2–10 times as much S and F as those of Scots pine. Microscopic observations showed various changes in the needle mesophyll cell ultrastructure. In both species, exposure to SO2 increased significantly the amount of cytoplasmic vacuoles, suggesting detoxification of excess sulphate or low pH. F treatments resulted in a significant enlargement of plastoglobuli in Scots pine and a darkening of plastoglobuli in Norway spruce. All exposures enhanced the accumulation of lipid bodies. An increased portion of translucent plastoglobuli was most pronounced in N treatments. Many of the ultrastructural changes and visible symptoms appeared only as number of years exposed increased, indicating that long-term experiments are needed. Both visible symptoms and ultrastructural changes pointed to the more pronounced sensitivity of Norway spruce compared to Scots pine. Ultrastructural results mostly supported earlier qualitative observations of F, N and SO2 effects on needle mesophyll cell ultrastructure. However, no reduction of thylakoids in SO2 containing exposure or curling of thylakoids in F exposure could be detected in the present study.
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  • 19
    ISSN: 0931-1890
    Keywords: Key words Conifer ; Fluoride ; Nitrogen ; Sulphur dioxide ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract  Effects of SO2, aqueous fluoride (NaF) and a solution of nitrogen compounds (NH4NO3) on the visible symptoms, pollutant accumulation and ultrastructure of Scots pine (Pinus sylvestris L.) and Norway spruce [Picea abies (L.) Karst.] seedlings were studied in an open-air experiment lasting for 3 consecutive years. Visible injury symptoms were most pronounced in combination exposures and whenever F was applied. Visible symptoms correlated well with needle pollutant concentrations. Exposure to NaF increased needle F contents particularly when F was applied with SO2 or NH4NO3. This suggests that a reduction in N or SO2 emissions, in F polluted areas, could improve the condition of conifers via decreased accumulation of phytotoxic F in the needles. Norway spruce needles accumulated 2 – 10 times as much S and F as those of Scots pine. Microscopic observations showed various changes in the needle mesophyll cell ultrastructure. In both species, exposure to SO2 increased significantly the amount of cytoplasmic vacuoles, suggesting detoxification of excess sulphate or low pH. F treatments resulted in a significant enlargement of plastoglobuli in Scots pine and a darkening of plastoglobuli in Norway spruce. All exposures enhanced the accumulation of lipid bodies. An increased portion of translucent plastoglobuli was most pronounced in N treatments. Many of the ultrastructural changes and visible symptoms appeared only as number of years exposed increased, indicating that long-term experiments are needed. Both visible symptoms and ultrastructural changes pointed to the more pronounced sensitivity of Norway spruce compared to Scots pine. Ultrastructural results mostly supported earlier qualitative observations of F, N and SO2 effects on needle mesophyll cell ultrastructure. However, no reduction of thylakoids in SO2 containing exposure or curling of thylakoids in F exposure could be detected in the present study.
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  • 20
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    Cellular and molecular life sciences 52 (1996), S. 259-263 
    ISSN: 1420-9071
    Keywords: Senecio cannabifolius ; Compositae ; foliar surface chemistry ; tobacco cutworm ; Spodoptera litura ; Lepidoptera ; Noctuidae growth inhibition ; ethyl (1-hydroxy-4-oxocyclohexa-2,5-dien-1-yl) acetate ; methyl (1-hydroxy-4-oxocyclohexa-2,5-dien-1-yl) acetate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Dewaxed leaf surface extracts of 12 plants from Hokkaido, prepared by dipping fresh leaves in chloroform for 3 min, were used in a choice leaf-disk bioassay against larvae of the tobacco cutwormSpodoptera litura. Activity was found only in the extract ofSenecio cannabifolius, a very successful weed in Hokkaido. Individual fractions of the extract, however, were not active. Incorporation of the individual fractions of the surface extracts as well as fractions of the methanolic extracts of the leaf residue into an artificial diet fed to neonateS. litura led to the isolation of ethyl (1-hydroxy-4-oxocyclohexa-2,5-dien-1-yl) acetate, the major surface compound, as the active principle. This compound was also present in the methanolic extract of the leaf residue together with methyl (1-hydroxy-4-oxocyclohexa-2,5-dien-1-yl) acetate, which had the same growth inhibitory effect on the larvae. The presence of these compounds in the foliar surface and tissue suggests a defensive role against herbivores.
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  • 21
    ISSN: 1423-0445
    Keywords: sex pheromone ; synergist ; antagonist ; mate recognition ; reproductive isolation ; chemotaxonomoy ; phylogeny ; evolution ; Lepidoptera ; Tortricidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The geometric isomers (E,E)-, (E,Z)-, (Z,E)-, and (Z,Z)-8,10-dodecadien-1-yl acetate were identified as sex pheromone components or sex attractants in the tribes Eucosmini and Grapholitini of the tortricid subfamily Olethreutinae. Species belonging to the more ancestral Tortricinae were not attracted. Each one isomer was behaviourally active in males ofCydia andGrapholita (Grapholitini), either as main pheromone compound, attraction synergist or attraction inhibitor. Their reciprocal attractive/antagonistic activity in a number of species enables specific communication with these four compounds.Pammene, as well as otherGrapholita andCydia responded to the monoenic 8- or 10-dodecen-1-yl acetates. Of the tribes Olethreutini and Eucosmini,Hedya, Epiblema, Eucosma, andNotocelia trimaculana were also attracted to 8,10-dodecadien-1-yl acetates, but several otherNotocelia to 10,12-tetradecadien-1-yl acetates. The female sex pheromones ofC. fagiglandana, C. pyrivora, C. splendana, Epiblema foenella andNotocelia roborana were identified. (E,E)- and (E,Z)-8,10-dodecadien-1-yl acetate are producedvia a commonE9 desaturation pathway inC. splendana. CallingC. nigricana andC. fagiglandana females are attracted to wingfanning males.
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  • 22
    ISSN: 1423-0445
    Keywords: protein solubility ; insect yolk protein ; buffering capacity ; phenolics ; Lepidoptera ; gypsy moth ; Lymantria dispar ; Malacosoma disstria ; Choristoneura rosaceana
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A standard buffer (5 mM phosphate at pH 7) which is used to extract protein from insect eggs provided complete protein solubility for eggs from three of four tree-feeding lepidopteran species: obliquebanded leaf roller (Choristoneura rosaceana), forest tent caterpillar (Malacosoma disstria), and the eastern tent caterpillar (Malacosoma americanum). Under the same extraction protocol, egg proteins from the gypsy moth (Lymantria dispar), remained nearly insoluble. An array of methods typically used to solubilize insect egg proteins were tried and all but the most denaturing (2% SDS) were ineffective. Extraction buffers with typically high pH values were then evaluated. The results indicated that 1) solubility of gypsy moth egg proteins was pH dependent, and full solubility of most egg proteins required the extraction buffer to have a pH of 12 or more prior to the addition of eggs. We also determined that 2) the gypsy moth egg has a buffering capacity which must be surpassed for complete protein extraction, 3) low salt/high pH buffers gave slightly higher total protein values than did high salt/high pH buffers, 4) parental nutritional history (host species utilized) and egg developmental state (pre-embryonatedvs postembryonated/pre-hatch) were unrelated to the requirements for complete egg protein solubilization, and 5) the presence of soluble phenolics, compounds that have the potential to bind to protein and cause insolubility, was confirmed for the gypsy moth egg with 2-D paper chromatography and several other tests. Based on these results, we present a hypothesis about the cause of egg protein insolubility in the gypsy moth.
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  • 23
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    Calcified tissue international 59 (1996), S. 474-479 
    ISSN: 1432-0827
    Keywords: Bone ; Apatite ; Collagen ; Demineralization ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract A technique to correlate the ultrastructural distribution of mineral with its organic material in identical sections of mineralized turkey leg tendon (MTLT) and human bone was developed. Osmium or ethanol fixed tissues were processed for transmission electron microscopy (TEM). The mineralized tissues were photographed at high, intermediate, and low magnifications, making note of section features such as fibril geometry, colloidal gold distribution, or section artifacts for subsequent specimen realignment after demineralization. The specimen holder was removed from the microscope, the tissue section demineralized in situ with a drop of 1 N HCl, then stained with 2% aqueous vanadyl sulfate. The specimen holder was reinserted into the microscope, realigned with the aid of the section features previously noted, and rephotographed at identical magnification used for the mineralized sections. A one to one correspondence was apparent between the mineral and its demineralized crystal “ghost” in both MTLT and bone. The fine structural periodic banding seen in unmineralized collagen was not observed in areas that were fully mineralized before demineralization, indicating that the axial arrangement of the collagen molecules is altered significantly during mineralization. Regions that had contained extrafibrillar crystallites stained more intensely than the intrafibrillar regions, indicating that the noncollagenous material surrounded the collagen fibrils. The methodology described here may have utility in determining the spatial distribution of the noncollagenous proteins in bone.
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  • 24
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    Oecologia 108 (1996), S. 643-651 
    ISSN: 1432-1939
    Keywords: Migration rate ; Lepidoptera ; Mark-recapture study ; Population density ; Movement behaviour
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Rapidly increasing fragmentation of natural landscapes decreases the ability of many species to reach the smaller and more isolated patches of habitat in a metapopulation. The densities of local populations of several moth species and the butterfly Hipparchia semele in a network of small islands, and the rates of inter-island movement and movement patterns, were investigated, to determine the factors affecting the rate and pattern of movements. The estimated population densities ranged from 0.001 to 0.2 individuals/m2. The observed emigration and immigration rates depended on island isolation and various traits of the species, with great variability in migration rates among species. Thin-bodied, slow-flying species did not move among the islands, whereas many robust, fast-flying species moved among the islands relatively frequently. Migration rate increased significantly with body size and was significantly higher in oligophagous than in polyphagous species, suggesting that these factors are important determinants of the migration rate of the species. Migration rate was low when the surface temperature of the sea was low, and a greater proportion of individuals emigrated from small than large patches of habitat. The migration distances of female noctuids were shorter than those of males and those of both sexes of the butterfly H. semele. The observed movement patterns are consistent with a metapopulation structure in most of the moth species.
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  • 25
    ISSN: 1432-2145
    Keywords: Somatic embryogenesis ; Ultrastructure ; Pennisetum ; Poaceae ; Morphometrics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Ultrastructural changes during zygotic and somatic embryogenesis in pearl millet (Pennisetum glaucum [L.] R. Br.) were quantified using morphometric techniques. The total area per cell profile and the cell volume percentage of the whole cell, endoplasmic reticulum (ER), Golgi bodies, mitochondria, nuclei, lipids, plastids, starch grains and vacuoles were measured and comparisons made between three zygotic and three somatic embryo developmental stages. All measurements were taken from scutellar or scutellar-derived cells. Zygotic embryogenesis was characterized by increases in cell size, lipids, plastids, starch, Golgi bodies, mitochondria and ER. Somatic embryogenesis was characterized by two phases of cell development: (1) the dedifferentiation of scutellar cells involving a reduction in cell and vacuole size and an increase in cell activity during somatic proembryoid formation and (2) the development of somatic embryos in which most cell organelle quantities returned to values found in late coleoptile or mature predesiccation zygotic stages. In summary, although their developmental pathways differed, the scutella of somatic embryos displayed cellular variations which were within the ranges observed for later stages of zygotic embryogenesis.
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  • 26
    ISSN: 1432-2145
    Keywords: Key words Somatic embryogenesis ; Ultrastructure ; Pennisetum ; Poaceae ; Morphometrics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Ultrastructural changes during zygotic and somatic embryogenesis in pearl millet (Pennisetum glaucum [L.] R. Br.) were quantified using morphometric techniques. The total area per cell profile and the cell volume percentage of the whole cell, endoplasmic reticulum (ER), Golgi bodies, mitochondria, nuclei, lipids, plastids, starch grains and vacuoles were measured and comparisons made between three zygotic and three somatic embryo developmental stages. All measurements were taken from scutellar or scutellar-derived cells. Zygotic embryogenesis was characterized by increases in cell size, lipids, plastids, starch, Golgi bodies, mitochondria and ER. Somatic embryogenesis was characterized by two phases of cell development: (1) the dedifferentiation of scutellar cells involving a reduction in cell and vacuole size and an increase in cell activity during somatic proembryoid formation and (2) the development of somatic embryos in which most cell organelle quantities returned to values found in late coleoptile or mature predesiccation zygotic stages. In summary, although their developmental pathways differed, the scutella of somatic embryos displayed cellular variations which were within the ranges observed for later stages of zygotic embryogenesis.
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  • 27
    ISSN: 1432-2145
    Keywords: Cytoskeleton ; Microscopy ; Pinus sylvestris ; Pollen ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The organization ofPinus sylvestris pollen tubes during growth was studied by video microscopy of living cells and by electron microscopy after freeze-fixation and freeze-substitution (FF-FS). Pollen germinated and the tubes grew slowly for a total period of about 7 days. Some of the grains formed two tubes, while 10–50% of the tubes ramified. These features are in accordance with development in vivo. The cytoplasmic hyaline cap at the tip disappeared during the 2nd or 3rd day of culture. Aggregates of starch grains progressively migrated from the grain into the tube and later into the branches. Vacuoles first appeared at day 2 and eventually filled large parts of the tube. The tube nucleus was located at variable distances from the tip. Some of the organelles showed linear movements in a mostly circulatory pattern, but the majority of the organelles showed brownian-like movements. Rhodamine-phalloidin-stained actin filaments had a gross axial orientation and were found throughout the tube including at the tip. The ultrastructure of pollen tubes was well preserved after FF-FS, but signs of shrinkage were visible. The secretory vesicles in growing tips were not organized in a vesicle cone, and coated pits had a low density with only local accumulations, which is in accordance with slow growth. The mitochondria contained small cristae and a darkly stained matrix and were located more towards the periphery of the tube, indicating low respiratory activity and low oxygen levels. The dictyosomes carried typical trans-Golgi networks, but some contained less than the normal number of cisternae. Other elements of the cytoplasm were irregularly spaced rough endoplasmic reticulum, many multivesicular bodies, lipid droplets and two types of vacuoles. The typical organization associated with tip growth in angiosperm pollen tubes, e.g.Nicotiana tabacum, was not present inP. sylvestris pollen tubes. The different morphology may relate to the growth rate and not to the type of growth.
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  • 28
    ISSN: 1432-2145
    Keywords: Key words Cytoskeleton ; Microscopy ; Pinus sylvestris ; Pollen ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The organization of Pinus sylvestris pollen tubes during growth was studied by video microscopy of living cells and by electron microscopy after freeze-fixation and freeze-substitution (FF-FS). Pollen germinated and the tubes grew slowly for a total period of about 7 days. Some of the grains formed two tubes, while 10–50% of the tubes ramified. These features are in accordance with development in vivo. The cytoplasmic hyaline cap at the tip disappeared during the 2nd or 3rd day of culture. Aggregates of starch grains progressively migrated from the grain into the tube and later into the branches. Vacuoles first appeared at day 2 and eventually filled large parts of the tube. The tube nucleus was located at variable distances from the tip. Some of the organelles showed linear movements in a mostly circulatory pattern, but the majority of the organelles showed brownian-like movements. Rhodamine-phalloidin-stained actin filaments had a gross axial orientation and were found throughout the tube including at the tip. The ultrastructure of pollen tubes was well preserved after FF-FS, but signs of shrinkage were visible. The secretory vesicles in growing tips were not organized in a vesicle cone, and coated pits had a low density with only local accumulations, which is in accordance with slow growth. The mitochondria contained small cristae and a darkly stained matrix and were located more towards the periphery of the tube, indicating low respiratory activity and low oxygen levels. The dictyosomes carried typical trans-Golgi networks, but some contained less than the normal number of cisternae. Other elements of the cytoplasm were irregularly spaced rough endoplasmic reticulum, many multivesicular bodies, lipid droplets and two types of vacuoles. The typical organization associated with tip growth in angiosperm pollen tubes, e.g. Nicotiana tabacum, was not present in P. sylvestris pollen tubes. The different morphology may relate to the growth rate and not to the type of growth.
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  • 29
    ISSN: 1573-1561
    Keywords: Near infrared ; Eldana saccharina ; sugarcane ; host plant resistance ; surface wax ; herbivory ; multiple linear regression ; metabolic profiling ; Lepidoptera ; Pyralidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Multiple regression predictive models based on data acquired by near-infrared (NIR) spectrophotometry suggest that stalk surface wax components contribute towards resistance toEldana saccharina Walker in sugarcane. At least 35 sugarcane clones of known resistance were required to calibrate a predictive model that accounted for approximately 54% of the variation in resistance toEldana. Wavelengths chosen in multiple regression models suggest that alcohols and carbonyls are important in the wax contribution. Through the use of wax fractionation and gas chromatography, a high alcohol/aldehyde ratio and shorter carbon chain length appears to be associated with resistance. The use of NIR in the screening of wild germplasm and the early screening of breeding material for resistance, without prior knowledge of the biochemical mechanisms involved, is an exciting prospect. However, cause-and-effect relationships remain to be shown.
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  • 30
    ISSN: 1573-1561
    Keywords: Lepidoptera ; Gelechiidae ; Scrobipalpuloides absoluta ; tomato ; pest ; pheromone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The sex attractant ofScrobipalpuloides absoluta females is a 90:10 mixture of (3E,8Z,11Z)-3,8,11-tetradecatrien-1-yl acetate and (3E,8Z)-3,8-tetradecadien-1-yl acetate. Tetradecadienyl acetates bearing 8Z,11Z; 3E,8Z; and 3E,11Z double bonds were synthesized by stereospecific procedures; the mass spectral and gas chromatographic properties of the 3E,8Z isomer were found to be congruent with those of the tetradecadienyl acetate fromS. absoluta. In wind tunnel bioassays, a 10:1 mixture of synthetic (3E,8Z,11Z)-3,8,11-tetradecatrien-1-yl acetate and (3E,8Z)-3,8-tetradecadien-1-yl acetate was highly attractive toS. absoluta males. Interestingly, the presence of (8Z,11Z)-8,11-tetradecadien-1-yl acetate (10%) inhibited the response to (3E,8Z,11Z)-3,8,11-tetradecatrien-1-yl acetate completely.
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  • 31
    ISSN: 1573-1561
    Keywords: Attractant ; Cajanus cajan ; EAG ; Helicoverpa armigera ; kairomone ; Lepidoptera ; Noctuidae ; oviposition stimulant ; pheromone ; pigeonpea ; sesquiterpene ; β-caryophyllene ; α-humulene ; α-guajene ; α-muurolene ; γ-muurolene ; α-bulnesene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract FemaleH. armigera moths are highly attracted by a steam distillate from pigeonpea plants, one of their main hosts. A mixture of six compounds, all sesquiterpenes (β-caryophyllene,α-humulene,α-guajene,α-muurolene,γ-muurolene, andα-bulnesene), mixed in the proportions as found in the steam distillate, elicited the same behavioral responses (oriented upwind flights and contacts with the odor source) as the steam distillate. Onlyα-bulnesene was attractive by itself, but still less than the whole mixture. In addition, the sesquiterpene mixture acts as an oviposition stimulant. Both behavioral responses, orientation and oviposition, are concentration dependent. Electrophysiological recordings from female and male antennae (EAG) showed the same qualitative and quantitative responses to each of the compounds of the sesquiterpene mixture. The EAG responses to the original steam distillate were higher and similar to chickpea kairomonal components, which were also tested. The pigeonpea sesquiterpene mixture and its individual components elicited weak EAG responses only. The response of the male antenna to female-produced pheromone components was in the same range as the pigeonpea steam distillate.
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  • 32
    ISSN: 1573-1561
    Keywords: Sex pheromone ; Idaea aversata ; Idaea straminata ; Idaea biselata ; (Z,Z)-9,11-tetradecadienyl acetate ; (Z,Z)-7,9-dodecadienyl acetate ; (Z,E)-7,9-dodecadienyl acetate ; Lepidoptera ; Geometridae ; electroantennography ; single cell recording ; biosynthesis ; phylogeny ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Pheromone compounds so far identified from most geometrid moths consist of all-Z diene, triene, or tetraene hydrocarbons with chain lengths of C17 to C21, and their monoepoxide derivatives biosynthesized from linoleic and linolenic acids. The present study reports the occurrence of olefinic acetates as sex pheromones in three species of Geometridae. (Z,Z)-9,11-tetradecadienyl acetate and (Z,Z)-7,9-dodecadienyl acetate found in female gland extracts ofIdaea aversata elicited significant responses from conspecific male antennae in gas chromatography with electroantennographic detection (GCEAD). In extracts ofI. straminata, (Z,Z)-7,9-dodecadienyl acetate, (E,Z)-7,9-dodecadienyl acetate, and (Z,Z)-7,9-dodecadienyl acetate were found, and the synthetic compounds elicited strong responses from conspecific male antennae. In the third species,I. biselata, only (Z,Z)-7,9-dodecadienyl acetate was found in the female extracts, and this compound elicited a strong EAD response from the conspecific male antenna. The identities of the pheromone components inI. aversata andI. straminata were further confirmed according to their characteristic ions after GC-MS analyses. Single sensillum recordings fromI. aversata showed two types of pheromone-detecting sensilla present on the male antenna. One type contained two receptor neurons, one of which was specifically tuned to (Z,Z)-9,11-tetradecadienyl acetate, the other to (Z,E)-9,11-tetradecadienyl acetate. A second type contained one neuron responding to (Z,Z)-7,9-dodecadienyl acetate. The two types were clearly different also with respect to external morphology, the former being considerably longer and having a larger base diameter. Also inI. straminata two physiological types of sensilla could be distinguished. One type contained two neurons, one of which responded to (Z,Z)-7,9-dodecadienyl acetate, the other to (Z,E)-9,11-tetradecadienyl acetate. The second type contained one neuron, responding to (Z,Z)-7,9-dodecadienyl acetate. No correlation between external morphology and physiological response of the investigated sensilla was observed inI. straminata. In field tests, a two-component blend containing (Z,Z)-9,11-tetradecadienyl acetate and (Z,Z)-7,9-dodecadienyl acetate in a ratio of 10:1 was attractive to males ofI. aversata. This two-component blend was also attractive to males ofI. straminata, but in a ratio of 1:1. High numbers of maleI. biselata were caught in traps baited with (Z,Z)-7,9-dodecadienyl acetate alone. The incorporation of deuterium labels into pheromone components after topical application of deuterium-labeled palmitic acid confirmed that the pheromone components ofI. aversata could be synthesized from this precursor, as has been previously observed for acetate pheromone components of many other moth species. Our results suggest that an evolutionary reversal back to the production of palmitic acid-derived pheromone components has occurred within the geometrid subfamily Sterrhinae.
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  • 33
    ISSN: 1432-0878
    Keywords: Key words: Endocrine cells ; Stomach-ECL cells ; Ultrastructure ; Histamine ; α-Fluoromethylhistidine ; Secretory vesicles ; Rat (Sprague Dawley) ; Mouse (NMRI) ; Hamster (Syrian)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The oxyntic mucosa of the mammalian stomach is rich in endocrine cells, such as ECL cells, A-like cells, somatostatin cells, D1/P cells and, in some species, enterochromaffin cells. The various endocrine cell types can be distinguished on the basis of their characteristic cytoplasmic granules and vesicles. The ECL cells contain numerous large secretory vesicles and relatively few, small electron-dense granules and small clear microvesicles. We have suggested that in the rat the ECL cells contain most of the gastric histamine with the secretory vesicles as the major histamine storage site in these cells. α-Fluoromethylhistidine is an irreversible inhibitor of histidine decarboxylase, the histamine-forming enzyme. We have previously shown that this enzyme inhibitor depletes histamine from the ECL cells in the rat and reduces the number of secretory vesicles in the cytoplasm. In the present study, we have examined whether α-fluoromethylhistidine affects the ECL cells in other species and whether it affects other types of endocrine cells in the oxyntic mucosa of the rat. Mice, rats and hamsters were treated with the inhibitor (3 mg/kg per h) via minipumps subcutaneously for 24 h. This treatment lowered the oxyntic mucosal histamine concentration by 65–90% and the number and volume density of the secretory vesicles by 85–95% in the ECL cells of the three species examined. In contrast, the number and volume density of granules and microvesicles were not greatly affected. No evidence was found for an effect of α-fluoromethylhistidine on A-like cells, somatostatin cells or D1/P cells of the rat stomach, suggesting that, unlike the ECL cells, they do not contain histamine.
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  • 34
    ISSN: 1432-0878
    Keywords: Key words: Testis ; Nerve growth factor receptor ; Immunohistochemistry ; Ultrastructure ; Bovine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Nerve growth factor receptor (low-affinity form) was demonstrated immunohistochemically in bovine testis by using a monoclonal mouse anti-human antibody. In the 7-month-old fetus and in the early postnatal testis, the peritubular and intertubular fibroblast-like mesenchymal cells showed a strong reaction. Following differentiation of these cells into Leydig and myoid peritubular cells, the nerve growth factor receptor was no longer expressed. However, peritubular and intertubular testicular fibroblasts/fibrocytes, which are also derived from mesenchymal precursors, remained positive. Additionally, the nerve growth factor receptor was demonstrated in postnatal prespermatogonia, A-spermatogonia, I-spermatogonia and members of the spermatogonia precursor cell line; B-spermatogonia remained negative. In A-spermatogonia and I-spermatogonia, the expression of the nerve growth factor receptor was cell-cycle-dependent and was mostly observed during G1-phase. Pre-embedding ultrahistochemistry with gold-conjugated antibody followed by silver-enhancement revealed that the nerve growth factor receptor was localized at the outer cell surface. The metal granules showed a regular distribution in positive spermatogonia. In testicular fibroblasts/fibrocytes the long narrow processes were preferentially decorated.
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  • 35
    ISSN: 1432-0878
    Keywords: Key words: Enterochromaffin-like (ECL) cells ; Gastrin ; Granules/vesicles ; Hypertrophy ; Ultrastructure ; Rat (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Previously, we have investigated the effects of short-term (minutes to hours) and long-term (weeks to months) stimulation with gastrin on the histamine-producing enterochromaffin-like (ECL) cells in the oxyntic mucosa of rat stomach. The present study examines the response of the ECL cells of freely fed rats to sustained hypergastrinemia over a time span of a few hours to four weeks. Sustained hypergastrinemia was induced by the continuous subcutaneous infusion of human Leu15-gastrin-17. The histidine decarboxylase (HDC) activity and histamine concentration in the oxyntic mucosa were monitored throughout the study. ECL cell profiles in electron micrographs were analysed planimetrically. The HDC activity displayed a 4-fold increase within the first two days. Subsequently, it remained at a plateau. The histamine concentration increased 2- to 3-fold in response to gastrin. The rise in histamine was slower than the rise in HDC activity. At no time point was there a reduced concentration of histamine. The ECL cells increased in size after 4 days of hypergastrinemia, reaching a maximum cell profile area after 2 weeks and remaining enlarged for the duration of the study. The secretory vesicles were reduced in number after 1 day, returning gradually to the pre-stimulation value thereafter; their volume density remained reduced during the 6-day observation period. Vacuoles started to appear after 1 day of hypergastrinemia and their number and volume density increased, reaching a maximum after 4 days. The number and volume density of the microvesicles increased and plateaued after 2 days of hypergastrinemia. The number of granules per cell profile was unaffected but their volume density was greatly reduced after 4 days of hypergastrinemia (reflecting the ECL cell hypertrophy). The present findings establish the time course of activation of the ECL cells in response to sustained hypergastrinemia over a time span of a few hours to four weeks; a new ”steady state” situation at a high level of activity has been established after about a week.
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  • 36
    ISSN: 1432-0878
    Keywords: Key words: Phagocytosis ; Insect hemocytes ; Lectins ; Fungal entomopathogens ; Ultrastructure ; Immunocytochemistry ; Cytoskeleton ; Spodoptera exigua (Insecta) ; Paecilomyces farinosus (Fungi-Deuteromycotina)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Phagocytosis of blastospores of the fungal entomopathogen Paecilomyces farinosus by granular hemocytes from larvae of Spodoptera exigua (beet armyworm) was studied. Blastospores were opsonized with a galactose-specific lectin purified from S. exigua hemolymph or with peanut agglutinin prior to incubation with hemocytes. Observations of thin sections revealed that pseudopodia extending from granulocytes attached to ligands (lectins, lectin conjugates) on the blastospores, and that the ligands became detached from the fungal surfaces and were endocytosed by granulocytes via coated pits on the plasma membrane. Coated vesicles bearing the endocytosed molecules appeared to be transported to the hemocytic granules. In other cases, ligand still coated the blastospores after phagocytosis and may have later concentrated within the phagosome along with digested fungal cell wall components. Phagocytosis of blastospores and clustering of a biotinylated lectin conjugate on or within the granulocytes were inhibited by drugs targeting cytoskeletal elements. Actin was concentrated in the pseudopodia of phagocytic granulocytes and may be directly associated with lectin receptor(s). Microtubules were abundant in the granulocytes, sometimes in specific regions.
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  • 37
    ISSN: 1432-0878
    Keywords: Key words: Mineralization ; Matrix vesicles ; Dentine ; Ultrastructure ; Element analysis ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The purpose of this study was to elucidate the mineralization process of mantle dentine by ultrastructural and element-analytical investigation of matrix vesicles and successive stages. Upper second molars of albino rats were cryofixed and embedded in resin after freeze drying. Semithin dry sections were prepared for analyzing the calcium and phosphorus concentrations in the mineralized matrix vesicles or noduli, larger mineralized islands, and the mantle dentine. For ultrastructural studies, it was necessary to reduce section contact with hydrous fluids to a minimum in order to avoid preparation artifacts. The first mineral deposits were recognized as dot-like formations both in the interior of matrix vesicles and in association with the inner vesicle membrane. This indicated the existence of mineral nucleating sites located both at the inner membrane and at calcium-phosphate-binding macromolecules in the interior of the matrix vesicles. A significantly higher mineral content was found in mineralized matrix vesicles than in the mineralized extravesicular regions of the mineralized islands, suggesting the existence of a rapidly and densely mineralizing matrix in the matrix vesicles. A significant increase in mineral content per volume proceeding from the mineralized islands to mantle dentine suggested a further increase in the density of mineral.
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  • 38
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    Protoplasma 194 (1996), S. 63-68 
    ISSN: 1615-6102
    Keywords: Blastocystis hominis ; Central vacuole ; In vitro culture ; Accumulation ; Carbohydrates ; Lipids ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Morphological changes in the central vacuole during the growth in in vitro culture ofBlastocystis hominis were investigated by light and electron microscopy. Most cells in log phase and an early stationary phase showed a positive staining reaction in the central vacuole with PAS or Sudan black B stain, whereas cells in late stationary phase showed few positive reactions. Electron microscopic observations revealed that 95% ofB. hominis cells in log phase and 50% of cells in early stationary phase, had a substantial accumulation of electron-dense material in the central vacuole. In contrast, only 25% of the organisms in late stationary phase had an electron-dense central vacuole, while more than 50% of cells had an electron-lucent central vacuole. These results indicate thatB. hominis accumulated carbohydrates and lipids in the central vacuole during cell growth and that the organism probably consumed these metabolic substances during stationary growth. Therefore, it is strongly suggested that the central vacuole is an important organelle for storage of metabolic substances, such as carbohydrates and lipids, required for cell growth.
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  • 39
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    Protoplasma 193 (1996), S. 213-221 
    ISSN: 1615-6102
    Keywords: Decorated tubules ; Endoplasmic reticulum ; Nymphaea ; Sieve elements ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Bundles of decorated tubules found in the sieve elements ofNymphaea have been studied with the transmission electron microscope. Comparatively straight tubules (100 nm in diameter) arise from the endoplasmic reticulum during early stages of sieveelement development and subsequently associate into bundles of up to 100 tubules that parallel the longitudinal cell axis. From the start of their formation the tubules are structurally distinct from other ER profiles due to their dense decoration with particles. High magnifications reveal an orderly array of the particles (about 24 surround a 100 nm tubule) and suggest a modification of their membrane so that it is no longer dissolvable into a regular three-layered structure. Later during sieve-element ontogeny the decorated tubules get invaginated by smooth ER membranes, thereby squeezing out the intratubular (extracytoplasmic) space. As a result a double mantle is formed that surrounds a plasmatic cylinder. Decorated 100 nm tubules with inner membranes are present in enucleate mature sieve elements ofNymphaea alba andN. tuberosa. Considerably larger tubules (about 200 nm in diameter) were found inN. Candida andN. tetragona and occasionally also inNuphar and Barclaya, two other genera from the same family. The decoration of the tubules and their subsequent invagination by smooth membranes are discussed with respect to the controlled autolysis of sieve elements.
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  • 40
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    Protoplasma 195 (1996), S. 59-67 
    ISSN: 1615-6102
    Keywords: Endoplasmic reticulum ; Germination ; Lipid bodies ; Pisum sativum ; Plastid biogenesis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The ultrastructure of embryonic pea leaf cells was examined during the first 24 h of imbibition of dry seeds. Special attention was paid to plastids, which underwent two interesting interactions during this period. The first was a close physical association between the endoplasmic reticulum and plastids. The second was an association of numerous lipid bodies with the surface of plastids. The functional implications of these associations are considered.
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  • 41
    ISSN: 1615-6102
    Keywords: Scale insect ; Cochineal scale ; Hemocytes ; Coccid ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The ultrastructural study of free circulating hemocytes in the adult cochineal scale,Dactylopius confusus (Cockerell), demonstrated five cell types: prohemocytes, typical granulocytes (T-granulocytes), oenocytoids, plasmatocytes, and granulocytes with modified sub-cellular structure to perform a special synthetic and secretory function, which we refer to as “modified granulocytes” (M-granulocytes). Prohemocytes showed undifferentiated sub-cellular structure of the basic stem cell type (i.e., high cytoplasmic density with numerous ribosomes, centrally located large nucleus with a distinct nucleolus, and poorly developed endoplasmic reticulum). The commonly observed typical granulocytes (T-granulocytes) had several smooth endoplasmic reticulum (SER) with dilated cisternae and many SER-derived membrane bounded granules of different sizes and electron density. Oenocytoids were identified by the presence of many crystals, RER-originated fine secretory granules, and an eccentric nucleus. Plasmatocytes were easily characterized by their variable shapes and irregular outline with pseudopodia-like cytoplasmic extensions, possession of an elongated lobed nucleus, multivesicular bodies, RER-derived membrane bounded, electron-dense, lysosomelike vacuoles, well-developed SER cisternae, and numerous pinocytic and SER-originated vesicles of different sizes along the peripheral region. M-granulocytes comprised the largest proportion of hemocytes in all samples observed. M-granulocytes were distinguished not only by the presence of membrane bounded granules of different sizes and electron density, but by the possession of large nuclei with distinct nucleoli, many mitochondria, and a highly developed network of rough endoplasmic reticulum (RER). M-granulocytes had abundant, rosette-shaped, RER-derived chains of fine secretory granules, which accumulated in the cytoplasm and vacuoles, and were ultimately deposited into the hemolymph by exocytosis. These fine granules gave a positive result with periodic acid-Schiff (PAS) test. Based on RER-synthesized fine secretory granules (M-granulocytes), their ultimate deposition into hemolymph, the red pigmentation of hemolymph, positive PAS histochemical test of these granules, and the high population of these hemocytes, no such cell type has been described in previous studies in insects. The sub-cellular structure of the granulocyte in this insect has been modified to perform a special synthetic and secretory function (i.e., possibly the synthesis of the red pigment found in hemolymph, which has been the source of commercially important cochineal dye).
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  • 42
    ISSN: 1615-6102
    Keywords: Endoplasmic reticulum ; Metasequoia ; Phloem-loading ; Plasmodesmata ; Strasburger cells ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Symplasmic contacts of Strasburger cells in the mature needle ofMetasequoia glyptostroboides were analysed with special regard to changes of plasmodesmata in fine structure and distribution. In meristematic cells simple primary plasmodesmata are evenly distributed throughout the entire wall, whereas in mature Strasburger cells plasmodesmata are aggregated in defined, dome-shaped wall thickenings. The elongated, often multiple-branched cytoplasmic strands show a distinct neck region besides a considerably dilated sleeve region confluent with cavities, which have formed at branching sites of plasmodesmata in various planes of the wall thickening. Most branches radiating from these cavities connect the protoplasts of the adjacent cells; occasionally some strands are discontinuous. The desmotubules of both, continuous and discontinuous plasmodesmal branches exhibit great variability in structure and number: they may be partially dilated, multiple-stranded and branched within single plasmodesmal branches. Fine structurally, plasmodesmata of Strasburger cells show great resemblance with developing sieve pores of conifers. This characteristic fine structure implicates a special role of the endomembrane system for phloem loading in theMetasequoia leaf.
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  • 43
    ISSN: 1615-6102
    Keywords: Arabidopsis ; Pollen ; Vegetative cytoplasm ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Ultrastructural changes of pollen cytoplasm during generative cell formation and pollen maturation inArabidopsis thaliana were studied. The pollen cytoplasm develops a complicated ultra-structure and changes dramatically during these stages. Lipid droplets increase after generative cell formation and their organization and distribution change with the developmental stage. Starch grains in amyloplasts increase in number and size during generative and sperm cell formation and decrease at pollen maturity. The shape and membrane system of mitochondria change only slightly. Dictyo-somes become very prominent, and numerous associated vesicles are observed during and after sperm cell formation. Endoplasmic reticulum appears extensively as stacks during sperm cell formation. Free and polyribosomes are abundant in the cytoplasm at all developmental stages although they appear denser at certain stages and in some areas. In mature pollen, all organelles are randomly distributed throughout the vegetative cytoplasm and numerous small particles appear. Organization and distribution of storage substances and appearance of these small particles during generative and sperm cell formation and pollen maturation are discussed.
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  • 44
    ISSN: 1615-6102
    Keywords: Arabidopsis thaliana ; Cyst nematodes ; Development ; Histology ; Syncytium ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The beet cyst nematodeHeterodera schachtii is able to establish a feeding structure (syncytium) in the vascular tissue of roots and shoots ofArabidopsis thaliana. Histological and ultrastructural studies were performed to assess plant responses during the development of juvenile females under monoxenic conditions. After destructively invading a root the nematode selects and pierces a single procambial cell with its stylet and transforms it into an initial syncytial cell (ISC) by secretory activity. The first most obvious changes in the ISC occur in the vacuolar system and at the wall. Differentiation of a central vacuole is impeded resulting in the formation of numerous small vacuoles. Multivesicular and paramural bodies are formed. An electron translucent material is deposited on the cell wall. Partial dissolution of the cell wall leads to the formation of a syncytium. At the juveniles' last pre-adult developmental stage the syncytium attains its maximum longitudinal and radial extension, occupying a major part of the central cylinder. Its features are indicative of a very high level of metabolic activity. The hypertrophied syncytium is ensheathed by a peridermal cover in which secondary xylem and phloem elements are interspersed. When females die the syncytia degenerate. The ultrastructural and histological features of syncytia described from roots are also found in syncytia induced in aerial parts of the plant.
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  • 45
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    Journal of chemical ecology 22 (1996), S. 1783-1796 
    ISSN: 1573-1561
    Keywords: Fall web worm moth ; Hyphantria cunea ; Lepidoptera ; Arctiidae ; pheromone trap ; mark-recapture ; sampling range
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Newly emerged males ofHyphantria cunea (Drury) (Lepidoptera: Arctiidae), marked with different fluorescent colors, were recaptured by pheromone trapping. Three Uni-traps, baited with (3Z,6Z)9,10-epoxyheneicosadiene, (9Z,12Z,15Z)octadecatrienal, and (3Z,6Z)9,10-epoxyheneicosa-triene in a 1:10:1 ratio, total 6 mg/dispenser, were placed in a line 15 m apart, perpendicular to the dominant wind direction, and checked after 12, 36, and 60 hr. At dusk, releases of 10–25 males were made over distances from 30 to 250 m, during 4 periods over a soybean field (nonhost plant). Recapture rates were high; of a total of 176 males released, 115 were recaptured with 88% of these within 12 hours. Between 40 and 100% of males were recovered over shorter distances (30–150 m), and between 10–24% at longer distances (200 and 250 m). No other species or unmarked males were captured. The trapping period showed little effect on recaptures. The central trap of the three traps had somewhat higher catches, but the slope of the regression of recapture over distance did not differ among traps. There was a significant decline of recapture over distance (r=−0.56) for catches of individual traps but a large scatter. Summed recaptures per distance gave less scatter and hadr=−0.86, allowing calculation of the maximum sampling range (R s ) after 60 hr as 340 m with a 95% confidence interval of 190–710 m (regression of arcsin √p and √R). The area of sampling, found by integrating the probability function of recapture over distance, from the source to maximumR, was 7 ha. The high recapture rates and the longR,. compared to those in the literature for other taxa, indicate that pheromone traps are highly efficient sampling devices in this species.
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  • 46
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    Journal of chemical ecology 22 (1996), S. 949-972 
    ISSN: 1573-1561
    Keywords: Lepidoptera ; Danainae ; Idea leuconoe ; hairpencil ; pheromone ; Parsonsia laevigata ; pyrrolizidine alkaloid ; mellein ; defense
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Males of a giant danaine butterfly,Idea leuconoe, display hairpencils during courtship. The females were visually attracted to and olfactorily arrested by an artificial butterfly model to which male hairpencil extracts were added. The hairpencil extracts contained a complex mixture of volatiles, including pyrrolizidine alkaloid (PA) derivatives (danaidone, viridifloric β-lactone), aromatics (phenol,p-cresol, benzoic acid), terpenoids (geranyl methyl thioether, (E,E)-farnesol), a series of γ-lactones (6-hydroxy-4-undecanolides and its homologs), hydrocarbons [(Z)-9-tricosene, etc.], and several compounds with higher molecular weight. A mixture of the major volatiles applied to a butterfly dummy strongly elicited an abdomen-curling acceptance posture in females. Viridifloric β-lactone and danaidone induced significant electroantennogram responses on the female's antennae, suggesting their principal role together with other hairpencil components as a sex pheromone to seduce females.I. leuconoe males seem to acquire the precursor for both of the PA fragments from the host plant,Parsonsia laevigata (Apocynaceae), during the larval stage; thereby they do not show pharmacophagous behavior towards PA-containing plants during the adult stage. However, males are pharmacophagously attracted to and feed on a number of simple phenolic compounds in a manner similar to other danaine species towards PAs. Wild males sequester one of the phagostimulants, (−)-mellein, in the hairpencils in varying quantities. Phenolic compounds incorporated in the hairpencils may act primarily as warning odors linked with the defensive PAs present in the body tissues.
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  • 47
    ISSN: 1573-1561
    Keywords: Pine tree ; Pinus pinaster ; Lepidoptera ; Dioryctria sylvestrella ; oleoresin ; terpenes ; host selection ; resistance marker
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Gas chromatographic analysis of the volatile terpenes of the wood oleoresin of maritime pines showed that the relative proportions of terpenes within the same tree did not vary according to sampling height and date. Pruning and tree vigor did not affect terpene profiles, but oleoresin composition varied widely from tree to tree. The trees attacked byDioryctria sylvestrella contained a significantly higher percentage of limonene, longipinene, and copaene, and a discriminant analysis, using the relative percentage of six terpenes, significantly separated infested and uninfested trees. The olfactory sensitivity of adult moths to a series of 20 volatile chemicals, including maritime pine oleoresin components, was evaluated with the electroantennogram method. Both sexes were sensitive to monoterpenes, oxygenated terpenoid compounds, and oleoresin samples. The use of terpenes as host attractants and biochemical markers for resistance toD. sylvestrella is discussed.
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  • 48
    ISSN: 1573-1561
    Keywords: Helicoverpa assulta ; Noctuidae ; Lepidoptera ; calling behavior ; sex pheromone composition ; (Z)-9-hexadecenal ; (Z)-11-hexadecenal ; (Z)-9-hexadecenyl acetate ; (Z)-11-hexadecenyl acetate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Solvent extracts of individual pheromone glands were prepared from femaleHelicoverpa assulta (Guenée) at 2-hr intervals throughout the scotophase. The amounts of female sex pheromone components, (Z)-9-hexadecenal, (Z)-11-hexadecenal, (Z)-9-hexadecenyl acetate, and (Z)-11-hexadecenyl acetate, in the extracts were determined by gas chromatographic analysis. Although females called from early scotophase (2 hr) until late scotophase (6 hr) the quantity of extracted pheromone remained high at 8 hr, the end of the scotophase. More than 70% of the pheromone gland extracts contained sex pheromone components regardless of whether the donor females had been called or resting. Pheromone components were absent from gland extracts prepared at the onset of the scotophase. The quantity of (Z)-9-hexadecenal and (Z)-11-hexadecenal increased rapidly to reach a maximum of approximately 260 and 30 ng/female, respectively, that was maintained for up to 8 hr, the duration of the scotophase. The quantity of (Z)-9-hexadecenyl acetate and (Z)-11-hexadecenyl acetate increased continuously during the scotophase to peak at 600 and 30 ng/female, respectively, 8 hr into the scotophase. At the end of scotophase the quantity of all pheromone components decreased significantly.
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  • 49
    ISSN: 1573-1561
    Keywords: Gypsy moth ; green ash ; feeding inhibition ; Lymantria dispar ; Lepidoptera ; Lymantriidae ; Fraxinus pennsylvanica ; Oleacae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Green ash is one of the few tree species rejected as food by larvae of the generalist gypsy moth,Lymantria dispar L. (Lepidoptera: Lymantriidae). Such rejection is based especially on chemicals present in green ash foliage. The gypsy moth larval feeding-inhibitory activity is contained in the ethyl acetate extractables of green ash foliage. Three representative columnchromatographed fractions of the extractables contained antifeedant activity. Individual fractions showed weaker antifeedant activity compared to the total ethyl acetate extractables. Acid hydrolysis of the extractables destroyed antifeedant activity and yielded feeding stimulant activity at higher concentrations. The aqueous extractables were not feeding-inhibitory. Compounds in the green ash extractables were separated by TLC, HPLC, CC, and GC.
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  • 50
    ISSN: 1573-1561
    Keywords: Host location ; host habitat location ; Cotesia flavipes ; Cotesia sesamiae ; Hymenoptera ; Braconidae ; cereals ; parasitoid ; stemborers ; Lepidoptera ; Pyralidae ; Noctuidae ; Y-tube olfactometer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract FemaleCotesia flavipes Cameron andCotesia sesamiae (Cameron) were attracted to odors in a Y-tube olfactometer from uninfested maize (Zea mays L.), sorghum [Sorghum bicolor (L.)], and napier grass (Pennisetum purpureum Schumach). In dual choice tests,Cotesia flavipes showed a preference for maize over sorghum, while maize and napier grass were equally attractive. In contrast,Cotesia sesamiae preferred volatiles from sorghum and napier grass over those from maize. The two parasitoids were significantly more attracted to maize infested with the stemborers,Chilo partellus (Swinhoe),Chilo orichalcociliellus Strand,Sesamia calamistis Hampson, andBusseola fusca (Fuller), than uninfested maize. In dual choice tests,Cotesia flavipes andCotesia sesamiae were unable to discriminate between odors from plants infested by the different species of stemborers.
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  • 51
    ISSN: 1573-1561
    Keywords: Eriocrania semipurpurella ; Eriocrania sangii ; Eriocraniidae ; Lepidoptera ; sex pheromone ; GC-EAD ; chiral gas chromatography ; mass spectrometry ; synthesis ; field trapping ; nonan-2-one ; (Z)-6-nonen-2-one ; (2S,6Z)-nonen-2-ol ; (2R,6Z)-nonen-2-ol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The fifth abdominal segment of femaleEriocrania semipurpurella (Stephens) andE. sangii (Wood) contains a pair of exocrine glands. Hexane extracts of this segment were prepared from both species and analyzed by gas chromatography with simultaneous flame ionization and electroantennographic detection (EAD). For both species, the EAD active peaks were identified as nonan-2-one, (Z)-6-nonen-2-one, and (Z)-6-nonen-2-ol by means of mass spectrometry and comparison of retention indices with those of synthetic standards. Enantiomeric separation of chiral alcohols from the female extracts was achieved by gas chromatographic analysis on a cyclodextrin column. InE. semipurpurella, a mixture of (2S,6Z)-nonen-2-ol and (2R,6Z)-nonen-2-ol (2: I) was found, whereas inE. sangii (2S,6Z)-nonen-2-ol was the predominant enantiomer and only traces of theR enantiomer were indicated by the antennal response. In field tests, a blend of the three compounds was not attractive to conspecific males. A subtractive assay showed that the alcohol in various enantiomeric mixtures was the only attractive compound, whereas addition of (Z)-6-nonen-2-one to the alcohol completely inhibited the attraction of both species. A trapping experiment including a wide range of ratios between theR andS enantiomers showed that baits containing 95–100% of theS enantiomer were attractive to maleE. sangii, whereas males ofE. semipurpurella were attracted to all tested ratios of the enantiomers. However, the response profiles of maleE. semipurpurella differed between populations from southern Sweden, south Finland, and the Kola Peninsula in Russia. In south Sweden males were maximally attracted to a racemic mixture of the alcohols. At the Kola PeninsulaE. semipurpurella was attracted to baits containing 95–100% of theR enantiomer. In south Finland all tested ratios between 0 and 100%R enantiomer trappedE. semipurpurella, but the trap catches appeared to be bimodally distributed with peaks around 15 and 70%R enantiomer. The trapping results suggest the existence of pheromone races or sibling species among the specimens identified asE. semipurpurella.
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  • 52
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    Journal of chemical ecology 22 (1996), S. 513-539 
    ISSN: 1573-1561
    Keywords: Oviposition ; kairomone ; Helicoverpa zea ; corn earworm ; Lycopersicon ; Nicotiana ; host-plant selection ; insect chemoreception ; Lepidoptera ; Noctuidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Hexane extracts of leaves of 307 accessions from 73 host plant species ofHelicoverpa zea were analyzed by gas chromatography (GC) and used forH. zea oviposition and neonate larvae orientation bioassays. The gas chromatographic (GC) retention times of compounds statistically associated with behavioral activity were identified by correlation of GC peak area with oviposition and larval orientation preferences. Although taxonomically diverse in their origin, compounds for study were purified from extracts of species of the genusLycopersicon, due to their relative abundance. The structures of eight long-chain alkanes associated with oviposition preference were assigned by mass spectrometry, and the structures of five similarly associated organic acids and a terpenoid alkene were identified by1H and13C nuclear magnetic resonance spectroscopy. The structures of a number of other phytochemicals from the plant leaves were identified for comparative purposes, including a previously unknown terpene, 7-epizingiberene. Bioassays were performed on the isolated acids and on the alkane wax fractions of severalLycopersicon species, and significant differences were found in oviposition stimulation for both classes of compounds. Of the hundreds of compounds found in the extracts, none were observed to act as oviposition deterrents. The results of these bioassays may be useful in explaining the broad host range ofH. zea, as well as the process and evolution of host plant selection for oviposition.
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  • 53
    ISSN: 1573-1561
    Keywords: Corn ; Zea mays (L.) ; fall armyworm ; Spodoptera frugiperda (J. E. Smith) ; Lepidoptera ; feeding resistance ; hemicellulose
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The fall armyworm,Spodoptera frugiperda (J. E. Smith), (FAW) is a major pest of corn,Zea mays L., in the southeastern United States. The damage to pretassel corn is caused by larvae feeding primarily on immature inner whorls. In this study, resistant lines were found to contain more crude fiber in whorls, mostly hemicellulose and cellulose. While hemicellulose, chiefly an arabinoxylan, was higher in resistant (R) lines than in susceptible (S) lines, the distribution of constituent neutral sugars was very similar in the lines. Both lines also containedp-coumaric and ferulic acids. These phenolic acids are known to occur both in the free state and in the cell wall as complexes bound by ester linkages to the arabinose moiety of the arabinoxylan.13C NMR data showed that the intensity of the carbonyl carbon (184 ppm) in resistant hemicellulose was stronger, indicating a greater degree of cross-linking. Thus, resistant hemicellulose is both structurally different from susceptible hemicellulose and present in greater quantities. In two of three laboratory dietary tests, FAW larval weight gains were significantly higher on diets with (S) hemicellulose incorporated at the same level as (R) hemicellulose. Therefore, resistance to the FAW appears to be correlated with both a greater amount and a higher degree of cross-linking of the hemicellulose of (R) lines.
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  • 54
    ISSN: 1573-1561
    Keywords: Lepidoptera ; Elachistidae ; Stenoma cecropia ; sex pheromone ; identification ; electroantennography ; single sensillum recording ; field trapping (Z,E)-9,11-tetradecadienal ; (Z,E)-9,11,13-tetradecatrienal
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract (Z,E)-9,11-tetradecadienal (Z9,E11–14: Ald; 11%), (Z,E)-9,11,13-tetradecatrienal (Z9,E11, 13–14: Ald; 67%), (Z,E)-9,11-tetradecadienyl acetate (Z9,E11–14: Ac, 5.5%), and (Z,E)-9,11,13-tetradecatrienyl acetate (Z9,E11,13–14: Ac; 16.5%) were identified in the extracts of female pheromone glands ofStenoma cecropia (Lepidoptera: Elachistidae). From electroantennograms and single sensillum recordings, receptors toZ9,E11,13–14:Ald andZ9,E11–14: Ald were found on male antenna. Behavioral data were obtained from olfactometric tests in the laboratory and field trapping experiments in Colombia. It appeared that a blend ofZ9,E11,13–14:Ald (83%) andZ9,E11–14:Ald (17%) was attractive to males. These aldehydes are assumed to be components of the sex pheromone ofS. cecropia, whereas the acetates found in gland extracts might be precursors of the pheromone.
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  • 55
    ISSN: 1573-1561
    Keywords: Wind tunnel ; behavior ; single sensillum recording ; Spodoptera littoralis ; Lepidoptera ; Noctuidae ; Egyptian armyworm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The major component of the sex pheromone of femaleSpodoptera littoralis, (Z,E)-9,11-tetradecadienyl acetate (1), elicited all steps of the male behavioral sequence, i.e., wing fanning and taking flight, oriented upwind flight and arrival to the middle of the tunnel, close approach and contact with the source. The activity was equivalent to that elicited by virgin females. In the range of doses tested, the dosage of1 had no significant effect on the number of source contacts. Male response was significantly affected by light intensity, being optimum at 3 lux. Activity of the minor components (Z)-9-tetradecenyl acetate (2), (E)-11-tetradecenyl acetate (3), tetradecyl acetate (4), (Z)-11-tetradecenyl acetate (5), and (Z,E)-9,12-tetradecadienyl acetate (6) was significantly lower than that of the major component when assayed individually. In multicomponent blends compound4 appeared to strongly decrease the number of males arrested at the source, the effect being particularly important when compound5 was present in the blend. Results of single sensillum experiments confirmed the existence of two main physiologically distinct sensillar types. The most common type of sensilla contained a neuron that responded specifically to compound1. A second type of sensilla, located laterally on the ventral sensory surface, contained two receptor neurons responding to compound6 and to (Z)-9-tetradecenol. Among short sensilla, one hair responded to compound4 and could represent a minor sensillar type. No sensory neuron was found to detect the other minor pheromone compounds2, 3, and5.
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  • 56
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    Journal of chemical ecology 22 (1996), S. 161-171 
    ISSN: 1573-1561
    Keywords: Behavior ; Lobesia botrana ; oviposition ; insect ; Tortricid ; Lepidoptera ; fatty acids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Avoidance of occupied ovisposition sites supposes that females perceive information related to their own progency. Fatty acids identified from egg extracts have been reevaluated using a different extraction method, and we have investigated the dose-dependent oviposition response of European grape vine moths (Lobesia botrana) to myristic acid, palmitic acid, palmitoleic acid, stearic acid, oleic acid, linoleic acid, methyl palmitate, methyl oleate, and ethyl palmitate; all except ethyl palmitate have been identified from eggs ofL. botrana. A methylene dichloride extract of eggs fromL. botrana revealed the presence of saturated free fatty acids (myristic, palmitic, and stearic) and unsaturated acids (palmitoleic, oleic, linoleic, and linolenic) in amounts ranging from 3.9 ng/egg equivalent for myristic acid to 30 ng/egg equivalent for palmitic and oleic acids. The extract also contained traces of methyl palmitate and methyl stearate. The greatest avoidance indexes were observed in response to palmitic, palmitoleic, and oleic acids. All the other compounds tested caused weaker responses. A reduction in the number of eggs laid was observed when moths were exposed to each of the esters applied at 0.3 µg per application spot. Reduction in eggs laid was also observed at a 10-fold higher dose of oleic acid. The present results confirm that general and simple molecules can be involved in the regulation of oviposition site selection and that they may participate in chemical marking of the eggs.
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  • 57
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    Journal of chemical ecology 22 (1996), S. 2133-2155 
    ISSN: 1573-1561
    Keywords: Orientation ; attraction ; odor-modulated anemotaxis ; pheromone plumes ; casting ; simulation models ; Coleoptera ; Scolytidae ; Lepidoptera ; Anemotaxis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The sequence of arrival of the bark beetlesIps typographus andPityogenes chalcographus (Coleoptera: Scolytidae) at traps baited with their synthetic pheromones was monitored with a portable fraction collector. Histograms of the natural arrival patterns of both species were nonrandom and clumped at shorter time scales (1-, 2-, 4-, 5-, or 6-min cells) but appeared random at larger time scales (10, 20 or 30 min). Monte Carlo generation of similar histograms showed them to be random at all of these time scales. A stochastic computer model could graphically simulate insect orientation to odor sources based on present theories of odor-modulated anemotaxis and casting. Although this model was used throughout, since it assumes only that insects cast perpendicular to the current wind direction, a second model could slightly improve orientation success. However, the second model requires that the insect remember its ground path (upwind) prior to losing the plume (after an abrupt wind direction change). The effects of casting and flight parameters on orientation success and randomness of arrival sequence within various plumes were determined by simulation. Similarly, the effects of random walks in plume direction, plume width, and wind speed were explored. The results showed that dynamic random variations in plume direction and especially wind speed could cause an otherwise random arrival sequence (e.g., under constant wind) to become clumped and nonrandom. Therefore, the clumped arrival patterns of bark beetles and other insects, includingSpodoptera litura, at pheromone sources could result from random-walk fluctuations in wind speed and wind direction.
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  • 58
    ISSN: 1573-1561
    Keywords: Sex pheromone ; (E,E)-8,10-dodecadien-1-ol acetate ; antagonist ; inhibitor ; mating disruption ; behavioral observations ; field EAG ; Cydia nigricana ; Tortricidae ; Lepidoptera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Synthetic sex pheromone of the pea mothCydia nigricana. (E,E)-8,10-dodecadien-1-yl acetate (E8,E10–12 : Ac), was applied in a 3-ha pea field at a rate of 17 g/ha, in two different dispenser formulations. Aerial concentrations within pea canopy, as determined by a field electroantennogram (EAG) apparatus, were 2 and 3 ng/m3 in the two dispenser treatments. The validity of the EAG measurements was corroborated by sampling of field air, followed by gas chromatographic quantification ofE8,E10–12 : Ac. Males were attracted to fresh dispensers releasingE8,E10–12 : Ac plus less than 2% of the antagonisticE, Z; Z, E; andZ, Z isomers. Two days after placement, the proportion of these isomers had increased to 6%. Males were then no longer attracted to the dispensers, but were observed to fly out of the treated field. Male attraction to calling females was almost entirely suppressed, and attraction to traps baited with synthetic pheromone was significantly reduced. Larval infestation in the pheromone-treated field was 2%, compared to 36% in a control field.
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