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  • Articles  (382)
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  • Hymenoptera  (303)
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  • Springer  (382)
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  • Chemistry and Pharmacology  (382)
  • 1
    Electronic Resource
    Electronic Resource
    Seasonal Variation in Amount and Composition of Monoterpenes Emitted by Young Pinus pinea Trees – Implications for Emission Modeling (2000)
    Springer
    Journal of atmospheric chemistry 35 (2000), S. 77-99 
    Details
    ISSN: 1573-0662
    Keywords: monoterpene emission ; Mediterranean pine ; seasonal variation ; light ; temperature ; algorithms ; model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract Current inventories of terpenes released from vegetation consider only the short-term influences of light and temperature on emissions to simulate temporal variation during the year. We studied whole canopy emissions from young Pinus pinea during a 15-month enclosure in greenhouse chambers and examined data for other long-term influences. Mean daytime emission rates strongly increased during spring, reached an annual maximum of ≈ 200 pmol m−2 total needle area s−1 (1.1 μg g−1 leaf dry weight h−1) between mid June and mid August, strongly declined in fall and reached an annual minimum of ≈ 1 pmol m−2 s−1 (0.006 μg g−1 h−1) between January and February. Normalization to standard temperature and light conditions did not change the annual time course of emissions, but reduced summer to winter ratio from a factor of 200 to about 45. Seasonal variation was characterized also by changes in terpene composition: among the six main compounds, three (t-β-ocimene, linalool, 1.8-cineol) were exclusively emitted during sunlit hours in the main vegetation period, whereas the other (limonene, α-pinene, myrcene) were emitted day and night and throughout the seasons. The results suggest that different terpene sources in P. pinea foliage exist and that a great part of the annual emission course observed here results from seasonal influences on these sources. A global model to simulate plant emissions is proposed, which accounts for seasonal influences on emissions in addition to the short-term effects of temperature and light. The model is tested on field data and discussed for its general application.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006233010748
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  • 2
    Electronic Resource
    Electronic Resource
    Will changes in soil organic carbon act as a positive or negative feedback on global warming? (2000)
    Springer
    Biogeochemistry 48 (2000), S. 21-51 
    Details
    ISSN: 1573-515X
    Keywords: carbon cycle ; decomposition ; global change ; soil organic matter ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract The world's soils contain about 1500 Gt of organic carbon to a depth of 1m and a further 900 Gt from 1--2m. A change of total soil organic carbon by just 10% would thus be equivalent to all the anthropogenic CO2 emitted over 30 years. Warming is likely to increase both the rate of decomposition and net primary production (NPP), with a fraction of NPP forming new organic carbon. Evidence from various sources can be used to assess whether NPP or the rate of decomposition has the greater temperature sensitivity, and, hence, whether warming is likely to lead to an increase or decrease in soil organic carbon. Evidence is reviewed from laboratory-based incubations, field measurements of organic carbon storage, carbon isotope ratios and soil respiration with either naturally varying temperatures or after experimentally increasing soil temperatures. Estimates of terrestrial carbon stored at the Last Glacial Maximum are also reviewed. The review concludes that the temperature dependence of organic matter decomposition can be best described as: d(T) = exp[3.36 (T − 40)/(T + 31.79)] where d(T) is the normalised decomposition rate at temperature T (in °C). In this equation, decomposition rate is normalised to ‘1’ at 40 °C. The review concludes by simulating the likely changes in soil organic carbon with warming. In summary, it appears likely that warming will have the effect of reducing soil organic carbon by stimulating decomposition rates more than NPP. However, increasing CO2 is likely to simultaneously have the effect of increasing soil organic carbon through increases in NPP. Any changes are also likely to be very slow. The net effect of changes in soil organic carbon on atmospheric CO2 loading over the next decades to centuries is, therefore, likely to be small.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006238902976
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  • 3
    Electronic Resource
    Electronic Resource
    Studies on the Complexation Behavior of Thorium(IV). 1. Hydrolysis Equilibria (2000)
    Springer
    Journal of solution chemistry 29 (2000), S. 63-86 
    Details
    ISSN: 1572-8927
    Keywords: Thorium ; hydrolysis ; potentiometry ; solvent extraction ; temperature ; thermodynamics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The stability constants of thorium(IV) hydrolysis species have been measured at15, 25, and 35°C (in 1.0 mol dm−3 NaClO4) using both potentiometry and solventextraction. The results indicate the presence of the monomeric speciesTh(OH)3+, Th(OH)2+ 2, Th(OH)+ 3, and Th(OH)4, in addition to the polymericspecies Th4(OH)8+ 8 and Th6(OH)9+ 15. The polymeric species were found to beimportant, although the total thorium concentration was limited to 0.01–0.1mmol-dm−3. The solvent extraction measurements required the use of acetylacetone.As such, the stability constants of thorium(IV) with acetylacetone were alsomeasured using both potentiometry and solvent extraction. All logarithms of thestability constants were found to be linear functions of the reciprocal absolutetemperature indicating that ΔH o and ΔSo of reaction are both independent oftemperature (over the temperature range examined in the study).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005166517699
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  • 4
    Electronic Resource
    Electronic Resource
    Conductivity of Dilute Aqueous Electrolyte Solutions at High Temperatures and Pressures Using a Flow Cell (2000)
    Springer
    Journal of solution chemistry 29 (2000), S. 217-235 
    Details
    ISSN: 1572-8927
    Keywords: Flow-through cell ; conductivity ; electrolyte ; ion association ; temperature ; pressure ; LiCl ; NaCl ; KCl
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A flow-through electrical conductance cell was assembled in order to measuremolar conductances of dilute aqueous electrolytes with a high degree of accuracyat high temperatures and pressures. The design of the cell is based on the conceptdeveloped at the University of Delaware and built in 1995, with modificationsthat will allow the cell to operate at much higher temperatures (to 600°C) andpressures (to 300 MPa). At present, the cell has been tested successfully bymeasuring aqueous (10−4-10−3 mol-kg−1) solutions of LiCl, NaCl, and KCl attemperatures 25–410°C and pressures 9.8–33 MPa. The results are in goodagreement with reported values, including those measured with the Delawareflow-through cell. These new results are also complementary to our previousresults, which were measured with a static high-pressure cell. Measurements attemperatures near the critical point of water (374°C, 22.1 MPa) require the useof lower solution concentrations that were unachievable in the past with thestatic cell.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005146332605
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  • 5
    Electronic Resource
    Electronic Resource
    Identity and Function of Scent Marks Deposited by Foraging Bumblebees (2000)
    Springer
    Journal of chemical ecology 26 (2000), S. 2897-2911 
    Details
    ISSN: 1573-1561
    Keywords: Bombus ; Apidae ; Hymenoptera ; tarsal gland secretions ; foraging behavior ; repellency ; n-heneicosane ; n-tricosane ; (Z)-9-tricosene ; n-pentacosane ; n-heptacosane
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Foraging bumblebees can detect scents left on flowers by previous bumblebee visitors and hence avoid flowers that have been depleted of nectar. Tarsal secretions are probably responsible for this repellent effect. The chemical components of the tarsal glands were analyzed by combined gas chromatography–mass spectrometry for three species of bumblebee, Bombus terrestris, B. lapidarius, and B. pascuorum. The hydrocarbons identified were similar for each species, although there were interspecific differences in the relative amounts of each compound present. The tarsal extracts of all three species comprised complex mixtures of long-chain alkanes and alkenes with between 21 and 29 carbon atoms. When B. terrestris tarsal extracts were applied to flowers and offered to foraging bumblebees of the three species, each exhibited a similar response; concentrated solutions produced a repellent effect, which decreased as the concentration declined. We bioassayed synthetic tricosane (one of the compounds found in the tarsal extracts) at a range of doses to determine whether it gave a similar response. Doses ≥ 10−12 ng/flower resulted in rejection by foraging B. lapidarius. Only when ≤ 10−14 ng was applied did the repellent effect fade. We bioassayed four other synthetic compounds found in tarsal extracts and a mixture of all five compounds to determine which were important in inducing a repellent effect in B. lapidarius workers. All induced repellency but the strength of the response varied; heneicosane was most repellent while tricosene was least repellent. These findings are discussed in relation to previous studies that found that tarsal scent marks were attractive rather than repellent.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026406330348
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  • 6
    Electronic Resource
    Electronic Resource
    Recognition of Complex Odors by Restrained and Free-Flying Honeybees, Apis mellifera (2000)
    Springer
    Journal of chemical ecology 26 (2000), S. 2307-2319 
    Details
    ISSN: 1573-1561
    Keywords: Honeybee ; Apis mellifera ; Hymenoptera ; Apidae ; conditioned proboscis extension ; free-flying foragers ; olfactory discrimination ; floral volatiles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Complex odor recognition in the honeybee was investigated using two behavioral assays: (1) the conditioning of the proboscis extension (CPE) with restrained individuals, and (2) the observation of foragers visiting an artificial feeder in a flight room. Nine compounds, previously identified as oilseed rape flower volatiles, were tested either individually or in mixtures. Different sets of experiments were done to determine: (1) the acquisition rate of the nine compounds in the CPE assay, and (2) the discrimination of the individual compounds after conditioning to a mixture, using the CPE assay and free-flying foragers. After conditioning to a complex mixture, honeybees established a hierarchy among the components, with some of them accounting for a major part of the behavioral activity of the mixture. Both behavioral assays led to the same classification of compounds, indicating good agreement between discriminating abilities of restrained individuals and of a population of foragers. The key compounds for recognition of these mixtures were those that were well learned when presented individually. However, the recognition of some compounds was affected by the other components of the mixture, with the activity of some compounds being either enhanced or reduced.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005522826673
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  • 7
    Electronic Resource
    Electronic Resource
    Secretion of Venom and Dufour Glands in the Ant Leptogenys diminuta (2000)
    Springer
    Journal of chemical ecology 26 (2000), S. 2497-2506 
    Details
    ISSN: 1573-1561
    Keywords: Venom gland ; Dufour gland ; gas chromatography ; 4–methyl-3heptanol and esters ; ants ; Hymenoptera ; Formicidae ; Ponerinae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The venom glands of both workers and ergatoid queens of the ant Leptogenys diminuta contain 4–methyl-3–heptanol and a mixture of esters of this alcohol and long-chain fatty acids. Only the higher proportion of 4–methyl-3–heptanone in the queens represents a chemical difference between the castes. The Dufour gland secretion of workers and queens, however, shows considerable differences. Both share a series of long-chain hydrocarbons with 9and 7–pentacosene as the major substances of the secretion but are otherwise differentiated by the presence in the workers only of three farnesene isomers, whereas queens contain a wide range of substances. The mated queen had a very complex mixture of hydrocarbons, esters and terpenes. These substances were also present in the virgin females but in smaller quantities.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005528511208
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  • 8
    Electronic Resource
    Electronic Resource
    Effects of Temperature and Photoperiod on Phytotoxic Root Exudates of Cucumber (Cucumis sativus) in Hydroponic Culture (2000)
    Springer
    Journal of chemical ecology 26 (2000), S. 1953-1967 
    Details
    ISSN: 1573-1561
    Keywords: Allelopathy ; autotoxicity ; activated charcoal ; cucumber ; Cucumis sativus L ; 2,4-dichlorobenzoic acid ; organic acids ; photoperiod ; temperature ; root exudates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract In order to elucidate the effects of temperature and photoperiod on the quality and quantity of plant root exudates, a Japanese cucumber (Cucumis sativus, cv. Shougoin-Aonaga-Fushinari) was grown hydroponically in growth chambers under controlled temperature and photoperiod conditions with or without the addition of activated charcoal (AC) to the nutrient solutions. Fresh AC was used to trap the organic compounds exuded from cucumber roots every two weeks. Cucumber plants without AC were severely retarded in root growth and in the accumulation of dry matter, especially at high temperature and long photoperiod, compared to those with AC. The growth inhibitors, adsorbed on the AC or accumulated in the nutrient solution without AC, were extracted by organic solvents and analyzed by GC-MS. Benzoic acid and its derivatives, cinnamic acid derivatives, and fatty acids were identified. The rate of root exudation in vegetative and reproductive stages for some of these organic acids increased with the elevation of temperature and the elongation of photoperiod, and the mean rate was two or more times higher than the minimum exudation at low temperature with short photoperiod. Some of the identified compounds significantly inhibited the germination and/or root growth of lettuce and cucumber.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005509110317
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  • 9
    Electronic Resource
    Electronic Resource
    Odor Perception in the Bark Beetle Parasitoid Roptrocerus xylophagorum Exposed to Host Associated Volatiles (2000)
    Springer
    Journal of chemical ecology 26 (2000), S. 2507-2525 
    Details
    ISSN: 1573-1561
    Keywords: Roptrocerus xylophagorum ; parasitoid ; Hymenoptera ; Pteromalidae ; Dendroctonus frontalis ; Ips grandicollis ; bark beetle ; Scolytidae ; semiochemicals ; host location ; oxygenated monoterpenes ; bioassay ; GC-EAD ; GC-MS
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Y-tube olfactometer bioassays and combined gas chromatography–electroantennographic detector (GC-EAD) analyses were performed to investigate the specific odors utilized as host location cues by the bark beetle parasitoid, Roptrocerus xylophagorum, originating from the southeastern United States. R. xylophagorum parasitizes several economically important holarctic bark beetle species and females oviposit preferentially on late larval stages. Both female and male parasitoids were tested with volatiles derived from host infestations of either Dendroctonus frontalis, the southern pine beetle, or Ips grandicollis, the southern pine engraver. Tested volatiles were steam distillates from the bark of loblolly pine, Pinus taeda, infested with larvae of the respective bark beetle species. Combined gas chromatography–mass spectrometry (GC-MS) was employed for identification and quantification of the compounds in the steam distillates. To confirm the EAD activity of identified compounds, GC-EAD analyses were repeated with a synthetic blend composed predominantly of compounds in the crude extracts that had revealed apparent electrophysiological activity. In Y-olfactometer bioassays, female parasitoids were attracted to both of the above-mentioned distillates. Male parasitoids were tested with one of the distillates but failed to respond. In GC-EAD analyses, the sexes displayed similar relative sensitivities to the components of the blends. Males exhibited generally higher amplitudes of response to the tested compounds than females. Monoterpene hydrocarbons associated with the constitutive resin of the host tree did not elicit significant EAD responses. Compounds known to be associated specifically with the host–tree complex, such as certain oxygenated monoterpenes, generated the greatest EAD responses. Female parasitoids were attracted by a synthetic blend composed of several of the EAD active oxygenated monoterpenes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005580528046
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  • 10
    Electronic Resource
    Electronic Resource
    On the Development of the Temperature Concept (2000)
    Springer
    Journal of thermal analysis and calorimetry 60 (2000), S. 1081-1091 
    Details
    ISSN: 1572-8943
    Keywords: second law of thermodynamics ; temperature ; thermometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A brief outline of the history of development of the temperature concept in physics is given. Simultaneously, some persisting imperfections in the conceptual basis of classical thermodynamics closely related to the first and the second law of thermodynamics are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1010196716770
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  • 11
    Electronic Resource
    Electronic Resource
    Differences in the Denaturation Behavior of Ribonuclease A Induced by Temperature and Guanidine Hydrochloride (2000)
    Springer
    The protein journal 19 (2000), S. 345-352 
    Details
    ISSN: 1573-4943
    Keywords: Ribonuclease A ; limited proteolysis ; temperature ; guanidine hydrochloride ; unfolding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Moderate temperatures or low concentrations of denaturants diminish the catalytic activity of some enzymes before spectroscopic methods indicate protein unfolding. To discriminate between possible reasons for the inactivation of ribonuclease A, we investigated the influence of temperature and guanidine hydrochloride on its proteolytic susceptibility to proteinase K by determining the proteolytic rate constants and fragment patterns. The results were related to changes of activity and spectroscopic properties of ribonuclease A. With thermal denaturation, the changes in activity and in the rate constants of proteolytic degradation coincide and occur slightly before the spectroscopically observable transition. In the case of guanidine hydrochloride-induced denaturation, however, proteolytic resistance of ribonuclease A initially increases accompanied by a drastic activity decrease far before unfolding of the protein is detected by spectroscopy or proteolysis. In addition to ionic effects, a tightening of the protein structure at low guanidine hydrochloride concentrations is suggested to be responsible for ribonuclease A inactivation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026479212350
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  • 12
    Electronic Resource
    Electronic Resource
    Temperature Effects on Soil Mineralization of Polylactic Acid Plastic in Laboratory Respirometers (1999)
    Springer
    Journal of polymers and the environment 7 (1999), S. 101-108 
    Details
    ISSN: 1572-8900
    Keywords: Polylactic acid ; temperature ; respirometers ; soil degradation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract A respirometric system was used to analyze the biodegradation of high molecular weight (120,000 to 200,000 g mol−1) polylactic acid (PLA) plastic films in soil under laboratory conditions. The respirometric system consisted of air-conditioning pretraps, a soil reactor, and a carbon dioxide (CO2) posttrap. A 200-g homogeneous soil mixture of all-purpose potting soil : manure soil : sand [1 : 1 : 1 (w/w)] and 1.5 g of PLA plastic films in 1 × 1-cm2 squares was added to each bottle. The respirometers were placed in a 28, 40, or 55°C water bath for 182 days. Treatments (three replicates) included native corn starch (positive control), polyethylene (Glad Cling Wrap; negative control), and three PLA films: Ca-I (Cargill Dow Polymers LLC, monolayer), GII (Cargill Dow Polymers LLC, Generation II), and Ch-I (Chronopol; monolayer). The degree of polymer mineralization was indicated by the cumulative CO2 liberated from each respirometer. The initial average mineralization rate and total percentage mineralized of the PLA plastic films at 28, 40, and 55°C was 24.3, 41.5, and 76.9 mg/day with a 27, 45, and 70% carbon loss, respectively. No decrease in soil pH was observed after 182 days of mineralization. Hence, increase in soil temperature drastically enhanced the biodegradation of PLA plastic films in soil under laboratory conditions (P 〈 0.0001).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1021812418325
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  • 13
    Electronic Resource
    Electronic Resource
    Gustatory Response by the Hymenopteran Parasitoid Cotesia glomerata to a Range of Nectar and Honeydew Sugars (1999)
    Springer
    Journal of chemical ecology 25 (1999), S. 2863-2877 
    Details
    ISSN: 1573-1561
    Keywords: Cotesia glomerata ; Hymenoptera ; sugar ; taste ; nectar ; honeydew ; acceptance threshold ; sugar receptor ; selective ; food supplement
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The feeding response of food-deprived Cotesia glomerata to solutions of 14 naturally occurring sugars was determined. Glucose, fructose, sucrose, maltose, erlose, melezitose, trehalose, and stachyose all elicited a feeding response. The sugars differed, however, with respect to the lowest concentration at which they were accepted (acceptance threshold). The parasitoids showed no feeding response when presented with 2 M solutions of galactose, mannose, rhamnose, lactose, raffinose, and melibiose. Sugars from the latter group did not show a deterrent effect when offered to water-deprived parasitoids. When mannose, rhamnose, melibiose, or raffinose were combined with low molar solutions of either fructose or sucrose, sucrose acceptance was affected by mannose and raffinose, whereas no negative interactions were found in mixtures with fructose. Compared to acceptance thresholds reported in other insect systems, the responses of C. glomerata differ considerably with respect to both the range of saccharides accepted as well as the acceptance thresholds. The novel finding that the parasitoid accepts a number of sugars that fail to elicit a feeding response in its herbivorous hosts is of particular interest to the use of (selective) food supplements in biological control programs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1020868027970
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  • 14
    Electronic Resource
    Electronic Resource
    Oviposition Stimulant for a Gall-Inducing Sawfly, Euura lasiolepis, on Willow is a Phenolic Glucoside (1999)
    Springer
    Journal of chemical ecology 25 (1999), S. 943-953 
    Details
    ISSN: 1573-1561
    Keywords: Euura lasiolepis ; galling sawfly ; host selection ; Hymenoptera ; insect herbivore ; oviposition stimulant ; phenolic glucosides ; Salicaceae ; Salix ; Tenthredinidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The ovipositional stimulation for the shoot galling sawfly, Euura lasiolepis, whose natural host is the North American willow, Salix lasiolepis, was studied in response to its original host, Finnish willows, poplar species, and individual phenolic glucosides and fractions. The major phenolic glucosides in the natural host were salicortin and tremulacin, which were also the major components in the Finnish S. purpurea and S. rosmarinifolia. The natural host, S. lasiolepis, was chosen over six Finnish willow species in multiple-choice tests. Multiple-choice tests with six Finnish willow species and one Finnish popular species showed that S. rosmarinifolia was significantly more attractive than any of the other species by at least 16-fold. No-choice testing with phenolic glucosides showed the tremulacin fraction to be the significant ovipositional stimulant, which elicited probes with the ovipositor at least 19 times more frequently than other glucosides. A tremulacin fraction at 1.5% elicited significantly more probes than a tremulacin fraction tested at 0.4%. In addition, tremulacin was the only glucoside to induce prolonged and repeated probing with the ovipositor, lasting a mean of 6.4 sec per bout per female. Only single probes lasting a fraction of a second were observed in response to other glucosides. This is the second study showing a direct effect of a phenolic glucoside as an ovipositional stimulant for a sawfly, and it also suggests the existence of a mechanism that enables females to respond positively in a graded way to shoot length heterogeneity in host plants and populations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1020813305196
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  • 15
    Electronic Resource
    Electronic Resource
    Alkenes as a Sexual Pheromone in the Alfalfa Leaf-Cutter Bee Megachile rotundata (1999)
    Springer
    Journal of chemical ecology 25 (1999), S. 471-490 
    Details
    ISSN: 1573-1561
    Keywords: Hymenoptera ; Apoidea ; Megachile rotundata ; solitary bee ; cuticular hydrocarbons ; sexual behavior of males
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Because of its special biological features, the leaf-cutter bee Megachile rotundata is particularly well suited for breeding and use as a pollinator for fodder plants such as alfalfa. Its mating behavior has been extensively studied. Behavioral tests have shown that males explore any black spot as a potential mating partner. However, exclusive selection of young virgin females suggests involvement of olfactory cues in addition to visual stimuli. Experiments demonstrated that mating behavior could be induced in males by lures covered with pentane extracts of the epicuticular waxes of young females. These extracts contain 35% fatty acids, 26% alkanes, and 39% monoenes. Variations in the monoene subfraction allow distinction between young virgin females, which possess more 7-pentacosene and 9-pentacosene, and older females, which have more 5-monoenes. The findings show that male mate-seeking and copulatory activity is stimulated only by young female monoenes. A 40% increase in this activity was observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1020993518226
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  • 16
    Electronic Resource
    Electronic Resource
    Comparative Study of Mandibular Gland Secretions of Workers of Ponerine Ants (1999)
    Springer
    Journal of chemical ecology 25 (1999), S. 1395-1409 
    Details
    ISSN: 1573-1561
    Keywords: Hymenoptera ; Formicidae ; Ponerinae ; mandibular gland ; exocrine secretion ; chemical analysis ; alkylpyrazines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The chemical contents of the mandibular glands of workers of eight species of ponerine ants have been analyzed and quantified. In three species (Ectatomma sp. from Brazil, Odontomachus bauri, and Pachycondyla striata) the contents were essentially a mixture of alkylpyrazines only. Three species (Odontoponera transversa, Pachycondyla indica, and Pachycondyla obscuricornis) contained a mixture of alkylpyrazines and oxygenated compounds and some simple terpenes; and the remaining two (Diacamma vagans and a Diacamma sp. from India) had only oxygenated compounds present. The two Diacamma species were notable in containing a dioxaspiroundecane (a spiroketal), not hitherto found in ants. All the 33 known mandibular gland analyses of workers of ponerine ant species have been brought together in order to seek some pattern in the type of glandular contents. Although the majority (24 species) produce alkylpyrazines, there is no observable pattern on a tribe or genus level.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1020987028163
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  • 17
    Electronic Resource
    Electronic Resource
    Scent Marking in Male Premating Behavior of Bombus confusus (1999)
    Springer
    Journal of chemical ecology 25 (1999), S. 1489-1500 
    Details
    ISSN: 1573-1561
    Keywords: Bumblebees ; Hymenoptera ; Apidae ; Bombus confusus ; perching behavior ; scent marking ; site tenacity ; male–male interaction ; geranylcitronellol ; (Z)-9-octadecenyl acetate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Premating behavior in the species Bombus confusus Schenck, 1859 was studied. The marking habits of bumblebee males were revealed and the use of their labial gland secretion in scent marks was proved chemically. Identical compounds were present both in the labial gland secretion and on male-marked objects. This chemical proof is reported for the first time from natural conditions of a B. confusus locality. Males' flight activities, site tenacity, and male–male interactions are described in detail. Contrary to literature reports, male B. confusus behavior does not basically differ from that of already known perching bumblebee species.
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    URL: http://dx.doi.org/10.1023/A:1020824529729
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    Effects of Temperature and Relative Humidity on Polylactic Acid Plastic Degradation (1999)
    Springer
    Journal of polymers and the environment 7 (1999), S. 83-92 
    Details
    ISSN: 1572-8900
    Keywords: Polylactic acid ; temperature ; relative humidity ; degradation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Three high molecular weight (120,000 to 200,000 g mol−1) polylactic acid (PLA) plastic films from Chronopol (Ch-I) and Cargill Dow Polymers (GII and Ca-I) were analyzed for their degradation under various temperature and relative humidity (RH) conditions. Two sets of plastic films, each containing 11 samples, were randomly hung in a temperature/humidity-controlled chamber by means of plastic-coated paper clips. The tested conditions were 28, 40, and 55°C at 50 and 100% RH, respectively, and 55°C at 10% RH. The three tested PLA films started to lose their tensile properties when their weight-average molecular weight (M w) was in the range of 50,000 to 75,000 g mol−1. The average degradation rate of Ch-I, GII, and Ca-I was 28,931, 27,361, and 63,025 M w/week, respectively. Hence, GII had a faster degradation rate than Ch-I and Ca-I under all tested conditions. The degradation rate of PLA plastics was enhanced by the increase in temperature and relative humidity. This trend was observed in all three PLA plastics (Ca-I, GII, and Ch-I). Of the three tested films, Ch-I was the first to lose its mechanical properties, whereas Ca-I demonstrated the slowest loss, with mechanical properties under all tested conditions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1021808317416
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    Electrochemical synthesis of cupric oxide powder Part II: Process conditions (1999)
    Springer
    Journal of applied electrochemistry 29 (1999), S. 81-85 
    Details
    ISSN: 1572-8838
    Keywords: cupric oxide ; powder ; current density ; temperature ; sodium sulfate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Notes: Abstract Electrosynthesis of cupric oxide powder was carried out on a laboratory scale in an electrochemical cell under various experimental conditions. The electrolysis was appraised in terms of the particle size of the cupric oxide product and the anodic dissolution of the copper electrode. Using a previously determined pH value of 7.50, the other optimum electrolysis operating conditions established were a current density of 4000Am−2, temperature of 353K, and Na2SO4 concentration of 0.5m. The optimum values of current efficiency, cell voltage and specific energy consumption for the electrochemical synthesis of cupric oxide powder were determined.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003464914657
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    Sulfate solubility algorithms for CaSO4–NaCl–H2O and Na2SO4–NaCl–H2O in chlor alkali brine at 25, 65, 75 and 85 ∘C (1999)
    Springer
    Journal of applied electrochemistry 29 (1999), S. 525-528 
    Details
    ISSN: 1572-8838
    Keywords: brine ; chlor-alkali cells ; solubility ; sulfate ions ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026405806916
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  • 21
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    Methane emissions from wet grasslands on peat soil in a nature preserve (1999)
    Springer
    Biogeochemistry 44 (1999), S. 205-220 
    Details
    ISSN: 1573-515X
    Keywords: grassland ; ground water level ; methane ; peat ; temperature ; wetland
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract The area of wet grasslands on peat soil in the Netherlands is slowly increasing at the expense of drained, agriculturally used grasslands. This study aimed (i) to assess the contribution of wet grasslands on peat soil to methane (CH4) emissions, and (ii) to explain differences among sites and between years in order to improve our understanding of controlling factors. For these purposes, a field study was conducted in the period 1994–1996 in the nature preserve “Nieuwkoopse Plassen”, which is a former peat mining and agricultural area. Net CH4 emissions were measured weekly to monthly with vented closed flux chambers at three representative sites, and at ditches near these sites. Three-years average of CH4 emissions was 7.9 g CH4 m- 2 yr-1 for Drie Berken Zudde, 13.3 for Koole, and 20.4 for Brampjesgat. Ditches near the sites emitted 4.2–22.5 g CH4 m-2 yr-1. The time-course of CH4 emissions for all experimental sites and years was fit with a multiple linear regression model with ground water level and soil temperature as independent variables. Lowering or raising the ground water level by 5 cm could decrease or increase CH4 emissions by 30–50%. Therefore, ground water level management of these grasslands should be done with care.
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    URL: http://dx.doi.org/10.1023/A:1006061814731
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  • 22
    Electronic Resource
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    Methane emissions from wet grasslands on peat soil in a nature preserve (1999)
    Springer
    Biogeochemistry 44 (1999), S. 205-220 
    Details
    ISSN: 1573-515X
    Keywords: grassland ; ground water level ; methane ; peat ; temperature ; wetland
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract The area of wet grasslands on peat soil in the Netherlands is slowly increasing at the expense of drained, agriculturally used grasslands. This study aimed (i) to assess the contribution of wet grasslands on peat soil to methane (CH4) emissions, and (ii) to explain differences among sites and between years in order to improve our understanding of controlling factors. For these purposes, a field study was conducted in the period 1994–1996 in the nature preserve “Nieuwkoopse Plassen”, which is a former peat mining and agricultural area. Net CH4 emissions were measured weekly to monthly with vented closed flux chambers at three representative sites, and at ditches near these sites. Three-years average of CH4 emissions was 7.9 g CH4 m−2 yr−1 for Drie Berken Zudde, 13.3 for Koole, and 20.4 for Brampjesgat. Ditches near the sites emitted 4.2–22.5 g CH4 m−2 yr−1. The time-course of CH4 emissions for all experimental sites and years was fit with a multiple linear regression model with ground water level and soil temperature as independent variables. Lowering or raising the ground water level by 5 cm could decrease or increase CH4 emissions by 30–50%. Therefore, ground water level management of these grasslands should be done with care.
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    URL: http://dx.doi.org/10.1007/BF00992979
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    Voltammetric Analysis of Iodide and Diffusion Coefficients Between 25 and 85°C (1998)
    Springer
    Journal of solution chemistry 27 (1998), S. 373-393 
    Details
    ISSN: 1572-8927
    Keywords: Iodide ; voltammetry ; diffusion coefficients ; temperature ; Stokes–Einstein equation ; solvation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The oxidation wave of iodide in 0.075 mol-L−1 H2SO4 was analyzed at 25, 40, 55, 70, and 85°C. The reversibility of the I2/I− system was checked using logarithmic transforms, half-wave potentials, and by studying I −1 = f(ω−1/2). The limiting currents obtained enabled us to determine the diffusion coefficient of I− using Newman's equation. These experimental results were compared with Nernst's limiting values. The Stokes–Einstein equation is not verified. Hydration numbers for I− at different temperatures were established. An empirical equation is proposed to predict the evolution of diffusion coefficients in a sulfuric acid medium with temperature.
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    URL: http://dx.doi.org/10.1023/A:1022679716395
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  • 24
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    Premating Behavior of Bombus Confusus Males and Analysis of Their Labial Gland Secretion (1998)
    Springer
    Journal of chemical ecology 24 (1998), S. 183-193 
    Details
    ISSN: 1573-1561
    Keywords: Hymenoptera ; Apidae ; Bombus confusus ; bumblebees ; perching behavior ; marking pheromone ; geranylcitronellol ; (Z)-9-octadecenyl acetate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Premating behavior in the bumblebee Bombus confusus was studied. Visual searching for females is not the only premating strategy of this species, as was believed earlier. Males of B. confusus have a normally developed labial gland and its secretion is used to mark a perch from which they visually search for females. The labial gland secretion contains geranylcitronellol and (Z)-9-octadecenyl acetate as the main components.
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    URL: http://dx.doi.org/10.1023/A:1022353315874
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  • 25
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    Effect of Female Age on Daily Cycle of Sexual Pheromone Emission in Gregarious Egg Parasitoid Anaphes listronoti (1998)
    Springer
    Journal of chemical ecology 24 (1998), S. 1595-1610 
    Details
    ISSN: 1573-1561
    Keywords: Sexual pheromone ; daily cycle ; male attraction ; female age ; olfactometer ; egg parasitoid ; Hymenoptera ; Mymaridae ; Anaphes listronoti
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The temporal pattern of pheromone emission by Anaphes listronoti females was established in a four-arm olfactometer by observing, at 2-hr intervals, the response of 〈2-hr-old males to odor produced by individual virgin females of 〈1, 1, and 2 days of age. This is the first evidence of a sexual pheromone in a Mymaridae. Under a 16L:8D photoperiod and 24°C constant temperature, the responsiveness of males to females of different ages varied significantly during the photophase. When 〈1-day-old females were used, males made significantly more final choices in the pheromone field than odorless fields at 4 and 6 hr after the onset of the photophase, and their walking speed was significantly higher from 4 to 12 hr, suggesting that females began to release a long-range pheromone during this period. Final choices and high walking speed were observed earlier with 1- and 2-day-old females than with 〈1-day-old females, and there was a significant decrease in male responses at 6 hr after the onset of the photophase, suggesting a bimodal temporal pattern of sexual pheromone emission.
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    URL: http://dx.doi.org/10.1023/A:1020860326945
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  • 26
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    Identification of Semiochemicals Released During Aphid Feeding That Attract Parasitoid Aphidius ervi (1998)
    Springer
    Journal of chemical ecology 24 (1998), S. 1355-1368 
    Details
    ISSN: 1573-1561
    Keywords: Homoptera ; Aphididae ; Hymenoptera ; Braconidae ; tritrophic interactions ; host foraging ; plant volatiles ; semiochemicals ; induction ; synomones ; wind tunnel ; GC-EAG ; Acyrthosiphon pisum ; Aphidius ervi ; Vicia faba ; Aphis fabae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Herbivore induced release of plant volatiles mediating the foraging behavior of the aphid parasitoid Aphidius ervi was investigated using the pea aphid, Acyrthosiphon pisum, feeding on broad bean, Vicia faba. Behavioral responses were studied using an olfactometer and a wind tunnel. Volatiles obtained by air entrainment of aphid infested plants were more attractive to A. ervi than those from uninfested plants, in both behavioral bioassays. GC-EAG of both extracts showed a number of peaks associated with responses by A. ervi, but with some differences between extracts. Compounds giving these peaks were tentatively identified by GC-MS and confirmed by comparison with authentic samples on GC, using two columns of different polarity. The activity of pure compounds was further investigated by EAG and wind tunnel assays. Results showed that, of the compounds tested, 6-methyl-5-hepten-2-one was the most attractive for A. ervi females, with linalool, (Z)-3-hexen-1-yl acetate, (E)-β-ocimene, (Z)-3-hexen-1-ol, and (E)-β-farnesene all eliciting significantly more oriented flight behavior than a solvent control. Foraging experience significantly increased parasitoid responses to these compounds, with the exception of (E)-β-farnesene. Time-course GC analysis showed that feeding of A. pisum on V. faba induced or increased the release of several compounds. Release of two of these compounds (6-methyl-5-hepten-2-one and geranic acid) was not induced by the nonhost black bean aphid, Aphis fabae. During the analysis period, production of (E)-β-ocimene remained constant, but 6-methyl-5-hepten-2-one, linalool, geranic acid, and (E)-β-farnesene appeared during the first day after A. pisum infestation and increased in concentration with increasing time of aphid feeding.
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    URL: http://dx.doi.org/10.1023/A:1021278816970
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    Thermodynamics of Polyvinylacetate from 0 to 350 K (1998)
    Springer
    Journal of thermal analysis and calorimetry 54 (1998), S. 731-740 
    Details
    ISSN: 1572-8943
    Keywords: enthalpy ; entropy ; Gibbs energy ; heat capacity ; limiting polymerization temperature ; polyvinylacetate ; temperature ; thermodynamics of polymerization ; vinyl acetate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The temperature dependence of the heat capacity of vinyl acetate in the range 13 to 330 K and of polyvinylacetate between 4.9 and 330 K was determined by adiabatic vacuum calorimetry with an error of about 0.2%. Temperatures and enthalpies of physical transitions were measured. From the data obtained, the thermodynamic characteristics of melting of vinyl acetate and parameters of glass transition and glassy state of the monomer and polymer were calculated. The thermodynamic functions Ho(T)-Ho(0), So(T), Go(T)-Ho(0) were estimated for both materials from 0 to 350 K. The results of calculation and the literature value of enthalpy of bulk polymerization of vinyl acetate at T=350 K were used for the estimation of the thermodynamic parameters of its polymerization process ΔHpol o, ΔSpol o, ΔGpol oin the interval 0 to 350 K. A ceiling limiting temperature of polymerization Tceil owas evaluated.
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    URL: http://dx.doi.org/10.1023/A:1010179517532
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    Hysteresis in the temperature response of carbon dioxide and methane production in peat soils (1998)
    Springer
    Biogeochemistry 43 (1998), S. 253-272 
    Details
    ISSN: 1573-515X
    Keywords: carbon dioxide ; hysteresis ; methane ; peat ; temperature ; wetlands
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract The ability to predict the effects of climate change on trace gas fluxes requires a knowledge of microbial temperature responses. However, the response of a microbial community to temperature in a given substrate may be complicated by its thermal history. To examine the effect of sequentially changing temperature on methane and carbon dioxide production in different peat types, we incubated anaerobic peat samples from 3 types of northern peatlands, a bog, a sedge fen and a cedar swamp, in both rising and falling temperature regimes. Graphic and statistical comparisons of the different temperature regimes suggest hysteresis in microbial response to temperature, although the absolute rates at any given temperature often did not differ. Where regressions for temperature response (Arrhenius plots) were significant, they generally differed between temperature regimes. The greatest differences among treatments occurred during the first half of the 40-d incubation. Increases in carbon dioxide production were similar across all peat types, but methanogenesis varied widely: methane production was uniformly low in the bog peat but increased sharply with temperature in the other two peat types. The complicating effect of history or chronology on substrate responses to environmental stimuli may restrain our ability to model the responses of complex systems to changing conditions.
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    URL: http://dx.doi.org/10.1023/A:1006097808262
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  • 29
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    Integrated Pharmacokinetic–Pharmacodynamic Model for Acetaminophen, Ibuprofen, and Placebo Antipyresis in Children (1998)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 26 (1998), S. 559-579 
    Details
    ISSN: 1573-8744
    Keywords: acetaminophen ; age ; antipyretic ; fever ; ibuprofen ; pediatrics ; pharmacokinetics ; pharmacodynamics ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A descriptive profile for antipyretic drug action has been documented for children. However, a linked pharmacokinetic–pharmacodynamic (PK/PD) model is central to the understanding of antipyretic drug action in febrile children. This was examined for previously reported data from 178 febrile children who received a single oral dose of acetaminophen (APAP) (12.5 mg/kg), ibuprofen (IBU) (5 or 10 mg/kg), or placebo. Rectal temperatures and plasma levels (μg/ml) of APAP and IBU were measured for up to 12 hr after drug administration. Nonlinear regression analyses were applied to these measurements and yielded simultaneous solutions of an integrated one-compartment PK, link, and SigmoidEmax effect model in 102/153 febrile children given APAP or IBU. The PK parameters (tlag ,ka , β,T1 / 2β ,AUC0–∞ ,Vd/F,andClp/F) were not different than those reported previously, except the APAPka was significantly lower. The link component yieldedkeo s of 0.58±0.06 (X±SE), 0.70±0.11 and 0.57 ± 0.11 hr -1 for APAP, IBU05, and IBU10, respectively: the SigmoidEmax component yieldedEC50 s (μg/ml) and sigmoidicity (γ) of 4.63±0.39 and 3.98±0.42 for APAP, 11.33±1.35 and 3.97±0.58 for IBU05 and 12.83±1.89 and 4.27±0.63 for IBU10. On visual inspection of the efficacy–time profiles of the febrile children, a number of them had an apparent linear function (slope; Δ°C/hr) and/or a sinusoidal cyclic function “confounding” standard approaches to PD analysis. Thus, the temperature profiles of 91/102 children given APAP or IBU required the addition of a slope (Δ°C/hr) and/or a sinusoidal cyclic function to the SigmoidEmax component to fit the data satisfactorily. All 22 children given a placebo also required a slope and/or a cyclic function in their PD model. The residual Δ°Cs (observed-predicted) of the placebo group were not significantly different from 0. Thus, no placebo antipyretic effect was observed. Dose dependency of IBUAUC0–∞ was confirmed; doubling the dose from 5 to 10 mg/kg increased theAUC0→∞ by only 1.5-fold. The confounding effect of initial temperature (Tempi ) on antipyretic efficacy in all treatment groups except placebo was also confirmed to expose nonlinear pharmacodynamics. A significant (p=0.03) contribution ofTempi (but not age) on the value of the slope function was found. There was no consistent effect of age orTempi , on the cyclic component of the integrated model of antipyresis. In addition, a multiple linear relationship of age andTempi was observed with a large number of the PK, link, and PD variables in those who received IBU. Dose, age, andTempi interacted with β in a significant multiple linear relationship withAUC0–∞ . The effects of IBU dose, age, andTempi are pervasive and cascade down the chain of events leading to the PD response. The etiology of pyresis may create the slope function, the magnitude of which may be partially due to the underlying disease. In some cases, the cyclic function may be explained by temperature regulation. Regardless of their cause, both confound analysis of drug action and make the simple, unmodified SigmoidEMax effect model less than satisfactory for interpretation of antipyretic drug effects. The influence of Tempi on the magnitude of antipyretic drug response is also a finding with major impact on PD investigations of antipyretic medications. In children receiving IBU, dose and age are also confounders, in addition toTempi . A multiplicity of covariables must be taken into account when developing appropriate dosing regimens for these antipyretics in febrile children.
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    High temperature conjugation of proteins with carbohydrates (1998)
    Springer
    Glycoconjugate journal 15 (1998), S. 131-138 
    Details
    ISSN: 1573-4986
    Keywords: protein ; conjugate ; carbohydrate ; lyophilization ; vaccine ; temperature ; heating
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A new procedure was used to conjugate lactose and dextran with BSA without using coupling or activating reagents. The method is simple, rapid and cheap. Reducing sugars covalently bind to proteins when lyophilized together and briefly heated to a high temperature.
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    URL: http://dx.doi.org/10.1023/A:1007067513242
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    Temperature effect on shear induced transition in surfactant solution (1997)
    Springer
    Colloid & polymer science 105 (1997), S. 322-325 
    Details
    ISSN: 1435-1536
    Keywords: Rheology ; surfactant solutions ; micelles ; phase transition ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Aqueous solutions of cationic surfactant with binding counterions exhibit a transition under shear. In this paper the steady shear properties of semidilute aqueous micellar solutions (cetylpyridinium chloride and sodium salicylate in brine) are presented as a function of concentration and temperature. The shear thinning behavior of this system could be described by the Carreau model at low shear rate and by a power law at higher shear rate. The temperature dependence of the zero shear viscosity follows an Arrhenius relationship. The critical shear rate at which the viscosity departs from its zero shear value is found to increase with temperature indicating the influence of this parameter on transition.
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    URL: http://dx.doi.org/10.1007/BF01188972
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    Comparative studies on some analytical methods (1997)
    Springer
    Journal of thermal analysis and calorimetry 49 (1997), S. 857-862 
    Details
    ISSN: 1572-8943
    Keywords: analytical methods ; kinetics ; powder milk ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract This work present comparative results on powder milk storage quality, obtained from analytical methods. Protein content was determined conventional (Kjeldahl) and colorimetric with biuret reagent at 540 nm and integral quality by thermogravimetric and biological methods. A method was developed for the protein separation of powder milk. Powder milk was submitted to degradation processes at 45, 60 and 80°C for 20 days. The results indicated that protein content values were inconsistent if determinations by Kjeldahl and colorimetric methods and biological tests were compared. There is evidence of thermal decomposition of powder milk as detected by biological and thermogravimetric methods.
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    Scent Marking, Scent Origin, and Species Specificity in Male Premating Behavior of Two Scandinavian Bumblebees (1997)
    Springer
    Journal of chemical ecology 23 (1997), S. 1235-1251 
    Details
    ISSN: 1573-1561
    Keywords: Labial gland ; male mating behavior ; marking pheromone ; Bombus pratorum ; Bombus lapidarius ; Hymenoptera ; Apidae ; GC-MS ; isoprenoids ; fatty acid derivatives
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The marking behavior and the scent-marking compounds in males of two Scandinavian bumblebee species Bombus pratorum and Bombus lapidarius were studied. There are characteristic differences in the behavior and in the chemistry of the two species. Males of B. pratorum scent marked small areas of the edges of birch leaves in a quick and unpredictable manner, depositing farnesol, geranylgeranyl acetate, farnesyl acetate, (Z)-11-octadecanol, hexadecanol, and a pentacosadiene. In B. lapidarius, scent marking on birch leaves was much slower and the entire edge of the leaf was marked with (Z)-9-hexadecenol and hexadecanol. These compounds were also detected in the cephalic portion of the labial gland in males. Thus, males of B. lapidarius produce a blend of fatty acid derivatives while B. pratorum males, in addition to fatty acid derivatives, also produce sesqui- and diterpenes. The total amount of scent compounds per milligram of labial glands was 0.2 μg in B. pratorum and 40 μg in B. lapidarius. Farnesol and farnesyl acetate were detected via headspace collection in the air around leaves marked by B. pratorum and (Z)-9-hexadecenol was detected around leaves marked by B. lapidarius.
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    URL: http://dx.doi.org/10.1023/B:JOEC.0000006461.69512.33
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    Electrophysiological and Behavioral Evidence for a Sex Pheromone in the Wasp Bephratelloides pomorum (1997)
    Springer
    Journal of chemical ecology 23 (1997), S. 1281-1289 
    Details
    ISSN: 1573-1561
    Keywords: Bephratelloides pomorum ; B. cubensis ; Annona muricata ; portable EAG ; sex pheromone ; Hymenoptera ; Eurytomidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Field experiments showed that males of the seed-feeding, Neotropical wasp Bephratelloides pomorum are strongly attracted to females. That this attraction was semiochemically mediated was demonstrated by both the response of male antennae to the whole-body extract of females and by behavioral bioassays. In the field, males were captured in traps baited with female thoraces, but not with other body parts (abdomen and head). Volatiles collected from the headspace of female wasps or whole-body extracts, concentrated and transferred to cotton plugs, elicited a full sequence of sexual behavior in male wasps. The attraction of males to female-baited traps showed a peak of activity at noon, but in indoor bioassays male responded to female extracts even at night.
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    Evidence for a Substrate-Borne Sex Pheromone in the Parasitoid Wasp Trichogramma brassicae (1997)
    Springer
    Journal of chemical ecology 23 (1997), S. 1349-1360 
    Details
    ISSN: 1573-1561
    Keywords: Sex pheromone ; substrate-borne chemical ; egg parasitoid ; Hymenoptera ; Trichogrammatidae ; Trichogramma brassicae ; mating structure ; videotracking
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract While the use of chemical cues in host location is well known in parasitoid insects, little is known about their role in sexual communication. Sex pheromones were investigated in the egg parasitoid Trichogramma brassicae, and the evidence for a substrate-borne pheromone was demonstrated. Mated and unmated males concentrated their walking in an area where virgin females (〈1 or 5 days old) had walked. Males were tested 15 min after females left the area. Male response decreased over time but was always significant during the 8 min of tracking. This suggests that females deposit chemicals on the substrate for mate finding. The pheromone is soluble in hexane, as shown by two kinds of extracts: female body rinsing and rinsing of the flask where females had walked. Hexane extracts resulted in a positive response by males. The response to different doses showed a saturation above a threshold of 4–8 female equivalents. The results do not exclude the possibility that a volatile part of the pheromone attracts males over long distances. Substrate-borne pheromones may increase mating chances for virgin females searching for oviposition sites, and may also increase mating chances on emergence sites by reducing male dispersion.
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    URL: http://dx.doi.org/10.1023/B:JOEC.0000006468.19993.70
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    (Z)-11-Eicosen-1-ol, a Major Component of Apis cerana Venom (1997)
    Springer
    Journal of chemical ecology 23 (1997), S. 1929-1939 
    Details
    ISSN: 1573-1561
    Keywords: (Z)-11-Eicosen-1-ol ; octadecanol ; eicosanol ; docosenol ; alarm pheromone ; venom ; Apis cerana ; Apis koschevnikovi ; Apis dorsata ; Apidae ; Hymenoptera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The unusual venom of Apis cerana contains large oily droplets within an otherwise aqueous secretion. Chemical analysis (GC-MS) revealed that the venom oil consists of (Z)-11-eicosen-1-ol (81.2%), other linear alcohols (7.7%), and linear hydrocarbons (11.1%). The eicosenol is present in extremely large quantities, averaging over 250 μg per insect, and is absent, or present in small quantities, in other parts of the sting apparatus. An investigation of the site of eicosenol storage in A. mellifera showed it to be absent from the venom and to be associated with the setose area where the more volatile components of the alarm pheromone are stored, as previously shown by others. A third honeybee species, A. dorsata, does not to contain the alcohol. The function of eicosenol in A. cerana in not clear, but may serve to mark stung intruders with pheromone or to attract foragers to marked floral resources.
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    URL: http://dx.doi.org/10.1023/B:JOEC.0000006480.49252.df
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    Response of Egg Parasitoid Telenomus busseolae to Sex Pheromone of Sesamia nonagrioides (1997)
    Springer
    Journal of chemical ecology 23 (1997), S. 2437-2444 
    Details
    ISSN: 1573-1561
    Keywords: Parasitoid ; Hymenoptera ; Scelionidae ; corn ; Lepidoptera ; Noctuidae ; semiochemicals ; Y-tube olfactometer ; kairomone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The olfactory cues involved in the host-finding behavior of Telenomus busseolae Gahan, a solitary egg parasitoid of the corn stalk borer, Sesamia nonagrioides (Lefebvre), were studied. The female wasp was attracted to odors from calling virgin females of S. nonagrioides in a Y-tube olfactometer. No response was elicited by noncalling virgin female moths and/or mated female moths. A four-component commercially available sex pheromone of the corn borer was also tested, as were the individual components of the mixture. T. busseolae respond to the whole blend [(Z)-11-hexadecenyl acetate, (Z)-11-hexadecenol, (Z)-11-hexadecenal, and dodecyl acetate in the ratio of 8.5:1:1:2]. Z11–16:OH was the only compound that elicited no significant activity. These results suggest that the sex pheromone released by the host female S. nonagrioides is used by T. busseolae as an indirect cue to locate egg masses of this host.
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    URL: http://dx.doi.org/10.1023/B:JOEC.0000006657.11973.27
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    Volatile Plant Infochemicals Mediate Plant Preference of Trichogramma chilonis (1997)
    Springer
    Journal of chemical ecology 23 (1997), S. 2455-2465 
    Details
    ISSN: 1573-1561
    Keywords: Trichogramma chilonis ; Hymenoptera ; Trichogrammatidae ; pigeonpea ; sorghum ; Helicoverpa armigera ; host location ; airflow olfactometer ; plant volatiles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract In India, eggs of the polyphagous noctuid moth Helicoverpa armigera on sorghum are parasitized to high levels by Trichogramma spp., but only rarely are parasitized eggs found on pigeonpea. This study was conducted to test whether volatile plant infochemicals contribute to the different parasitism levels observed on these two crops. In a four-armed airflow olfactometer, volatiles emitted by both sorghum and pigeonpea plants elicited a behavioral response form Trichogramma chilonis females. The parasitoids' response varied depending on the growth stage of the plant. Volatiles emitted by sorghum in the vegetative and reproductive stages arrested the parasitoids. T. chilonis females did not respond to volatiles from pigeonpea in the vegetative stage, but were repelled by volatiles from plants in the reproductive stage. Plants in the reproductive stage are preferred for oviposition by H. armigera. Thus, sorghum is attractive and pigeonpea repellent to T. chilonis females at the time when each plant is attractive to the host. This difference in the parasitoids' response may partly explain the different levels of egg parasitism reported from these two crops. The infochemicals involved in these plant–parasitoid interactions are discussed in the context of the current terminology.
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    URL: http://dx.doi.org/10.1023/B:JOEC.0000006659.06960.ed
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    Semiochemical-Mediated Location of Host Habitat by Apanteles carpatus (Say) (Hymenoptera: Braconidae), a Parasitoid of Clothes Moth Larvae (1997)
    Springer
    Journal of chemical ecology 23 (1997), S. 459-472 
    Details
    ISSN: 1573-1561
    Keywords: Apanteles carpatus ; Tinea pellionella ; Hymenoptera ; Braconidae ; Lepidoptera ; Tineidae ; semiochemicals ; coupled gas chromatographic–electroantennographic detection ; host-habitat location ; tritrophic interactions ; geranylacetone ; nonanal
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract In Y-tube olfactometer bioassays, adult Apanteles carpatus (Say), were attracted to beaver or rabbit pelts infested with larvae of the casemaking clothes moth (CCM)Tinea pellionella L. Porapak Q-captured volatiles from a CCM-infested beaver pelt were also very attractive, whereas isolated CCM larvae or larval feces were not. Coupled gas chromatographic–electroantennographic detection (GC-EAD) analysis of the Porapak Q volatile extract revealed two compounds that elicited responses by A. carpatus antennae. Coupled GC–mass spectrometry (MS) in electron impact and chemical ionization modes of these compounds indicated, and GC-MS and GC-EAD of authentic standards confirmed, that they were nonanal and geranylacetone. While each compound singly did not attract A. carpatusa 1:1 blend of both compounds was as attractive as the volatile extract. Because these compounds are host habitat-derivedA. carpatus must be a habitat rather than host specialist, responding to kairomonal indicators of localized and specific habitats such as animal hair or feather. The tritrophic interaction between A. carpatusits clothes moth hosts and their animal-derived habitats is similar to the well-studied relationship between parasitoids of insect herbivores and their host plant habitats.
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    URL: http://dx.doi.org/10.1023/B:JOEC.0000006371.64333.c2
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    Absolute Configuration of 4-Methyl-3-Heptanone and 4-Methyl-3-Heptanol from Mandibular Glands of Virgin Males and Females ofAtta sexdens rubropilosa (1997)
    Springer
    Journal of chemical ecology 23 (1997), S. 1569-1575 
    Details
    ISSN: 1573-1561
    Keywords: 4-Methyl-3-heptanone ; 4-methyl-3-heptanol ; Atta sexdens rubropilosa ; male ; female ; chirality ; Hymenoptera ; Formicidae ; gas chromatography-mass spectrometry ; chiral column gas chromatography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract (S)-;(+)-4-Methyl-3-heptanone is the principal component in the secretion from the mandibular glands of unmated and mated males and females ofAtta sexdens rubropilosa. In mated and unmated females, it is essentially the only component in the glandular secretion. In unmated males up to 50% of the secretion is a mixture of (3S, 4S)- and (3R, 4S)-4-methyl-3-heptanol. After mating, the amount of alcohol in the males decreases markedly.
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    Comparisons and Contrasts in Host-Foraging Strategies of Two Larval Parasitoids with Different Degrees of Host Specificity (1997)
    Springer
    Journal of chemical ecology 23 (1997), S. 1589-1606 
    Details
    ISSN: 1573-1561
    Keywords: Hymenoptera ; Braconidae ; Microplitis croceipes ; Cotesia marginiventris ; Gossypium hirsutum ; volatile chemicals ; systemic ; generalist ; specialist ; host location ; wind tunnel
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract In theory, the degree of specificity of the signals a parasitoid species needs to successfully locate its host correlates with its level of specialization. We examined this question by comparing the foraging strategies of two parasitoids that differ in their host ranges. In wind-tunnel experiments, we investigated how systemically released herbivore-induced volatiles were used by the generalist parasitoid,Cotesia marginiventris (Cresson) and the specialist,Microplitis croceipes (Cresson). We determined the relative influence of these volatiles as compared to other signals emitted in the host orientation of the two parasitoids. Both the generalist and the specialist parasitoid strongly preferredSpodoptera exigua (Hübner) leaf-induced systemic plants over undamaged plants when no other information was available. When wasps were given a choice between leaf-induced and undamaged plants carrying other plant- or host-related materials, the responses differed for the two species.C. marginiventris appeared to cue primarily on recent damage volatiles, whereasM. croceipes appeared to cue primarily on host frass volatiles. However, recent damage on previously leaf-induced plants, was strongly preferred to recent damage on plants previously damaged by both species. When plants were induced at the squares byHelicoverpa zea (Boddie), onlyM. croceipes exhibited a preference for these plants over undamaged plants. The adaptive significance of the behaviors as related to dietary specializations of the parasitoids is discussed.
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    URL: http://dx.doi.org/10.1023/B:JOEC.0000006424.41365.0d
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    Identification of Floral Volatiles Involved in Recognition of Oilseed Rape Flowers, Brassica napus by Honeybees, Apis mellifera (1997)
    Springer
    Journal of chemical ecology 23 (1997), S. 1715-1727 
    Details
    ISSN: 1573-1561
    Keywords: Honeybee ; Apis mellifera ; Hymenoptera ; Apidae ; Brassica napus ; oilseed rape ; flower volatiles ; conditioned proboscis extension ; olfactory recognition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Volatiles from oilseed rape, Brassica napus, flowers were sampled by air entrainment and their relevance to the natural odor profile of the flowers was confirmed by conditioned proboscis extension (CPE) assays with honeybee, Apis mellifera L., foragers. Coupled gas chromatography (GC)-CPE analysis of the air entrainment samples was used to locate key compounds involved in the recognition of B. napus flowers, and the compounds were then identified using coupled gas chromatography-mass spectrometry and comparison with authentic samples. Six regions of the gas chromatograms elicited CPE responses from bees previously conditioned to the total extract, and from these areas 16 compounds were identified that elicited CPE activity from conditioned bees when tested with synthetic samples. Eight of the 16, α-pinene, phenylacetaldehyde, p-cymene, α-terpinene, linalool, 2-phenyl-ethanol, (E,E)-α-farnesene, and 3-carene, gave the highest responses. When the bees were conditioned to the total extract of flower volatiles, a mixture of the eight components elicited responses from 83% of the individuals, suggesting that the eight-component mixture accounted for a major part of the CPE activity of the total extract. In addition, a mixture of the three most active compounds, phenylacetaldehyde, linalool, and (E,E,)-α-farnesene, evoked responses from 85% of the bees after the latter had been conditioned to the eight-component mixture. Thus, these three compounds appear to play a key role in the recognition of the eight component mixture and, by inference, of oilseed rape flowers.
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    URL: http://dx.doi.org/10.1023/B:JOEC.0000006446.21160.c1
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    Sex Pheromone of Cabbage Aphid Brevicoryne brassicae: Identification and Field Trapping of Male Aphids and Parasitoids (1997)
    Springer
    Journal of chemical ecology 23 (1997), S. 1881-1890 
    Details
    ISSN: 1573-1561
    Keywords: Aphid ; Brevicoryne brassicae ; Homoptera ; pheromone ; attractant ; Diaeretiella rapae ; Praon volucre ; Hymenoptera ; isoprenoid ; nepetalactone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The sex pheromone of the cabbage aphid, Brevicoryne brassicae, is shown by GC and GC-MS analysis of pheromone entrained from sexual females, and by electrophysiological studies on single cell preparations from male antennae, to comprise (4aS,7S,7aR)-nepetalactone. The compound proved to be attractive in a laboratory bioassay and release of the pheromone from glass vials placed above water traps in crops of autumn brassicaceous crops increased the catch of males of this species. The specialist parasitoid of B. brassicae, Diaeretiella rapae, and the more general aphid parasitoid Praon volucre were found in significantly larger numbers in pheromone traps as compared to the controls, under certain conditions.
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    URL: http://dx.doi.org/10.1023/B:JOEC.0000006457.28372.48
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    Effect of temperature on performanceof LaNi4.76Sn0.24 metal hydride electrode’ (1997)
    Springer
    Journal of applied electrochemistry 27 (1997), S. 1328-1332 
    Details
    ISSN: 1572-8838
    Keywords: metal hydride ; capacity ; temperature ; performance ; enthalpy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Notes: Abstract The effect of temperature on the performance of a LaNi4.76Sn0.24 metal hydride electrode was investigated in the temperature range of 0 to 50°C. The electrode showed a maximum discharge capacity at 25°C. The total resistance increases with a decrease of temperature from 50°C to 0°C. The apparent activation enthalpies at different states of charge were determined by evaluating the polarization resistance at different temperatures. It was found that the apparent activation enthalpy is an indicator of the relative reaction rate of the charge-transfer reaction and hydrogen absorption.
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    URL: http://dx.doi.org/10.1023/A:1018460709968
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    Effects of air pollutant-temperature interactions on mineral-N dynamics and cation leaching in reciplicate forest soil transplantation experiments (1997)
    Springer
    Biogeochemistry 39 (1997), S. 295-326 
    Details
    ISSN: 1573-515X
    Keywords: acidification ; aluminium ; Arrhenius’ law ; calcium ; cation leaching ; climate ; ion equilibrium ; forest soil ; N-cycle ; N-deposition ; nitrification ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract Increased emissions of nitrogen compounds have led to atmosphericdeposition to forest soils exceeding critical loads of N overlarge parts of Europe. To determine whether the chemistry offorest soils responds to changes in throughfall chemistry, intactsoil columns were reciprocally transplanted between sites, withdifferent physical conditions, across a gradient of N and Sdeposition in Europe. The transfer of a single soil to the various sites affected itsnet nitrification. This was not simply due to the nitrificationof different levels of N deposition but was explained bydifferences in physical climates which influenced mineralizationrates. Variation in the amount of net nitrification between soiltypes at a specific site were explained largely by soil pH. Within a site all soil types showed similar trends in netnitrification over time. Seasonal changes in net nitrificationcorresponds to oscillations in temperature but variable time lagshad to be introduced to explain the relationships. WithArrhenius‘ law it was possible to approximate gross nitrificationas a function of temperature. Gross nitrification equalled netnitrification after adaptation of the microbial community oftransplanted soils to the new conditions. Time lags, andunderestimates of gross nitrification in autumn, were assumed tobe the result of increased NH 4 + availability due either tochanges in the relative rates of gross and net N transformationsor to altered soil fauna-microbial interactions combined withimproved moisture conditions. Losses of NO 3 - were associated with Ca2+and Mg2+ in non-acidified soil types and with losses ofAl3+ in the acidified soils. For single soils the ionequilibrium equation of Gaines-Thomas provided a useful approximationof Al3+ concentrations in the soil solution as a functionof the concentration of Ca2+. The between site deviationsfrom this predicted equilibrium, which existed for single soils, couldbe explained by differences in throughfall chemistry which affectedthe total ionic strength of the soil solution. The approach of reciprocally transferring soil columnshighlighted the importance of throughfall chemistry, interactingwith the effect of changes in physical climate on forest soilacidification through internal proton production, in determiningsoil solution chemistry. A framework outlining the etiology offorest die-back induced by nitrogen saturation is proposed.
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    Micellization of triblock copoly(ethyleneoxide/tetrahydrofuran/ethylene oxide) (1997)
    Springer
    Colloid & polymer science 275 (1997), S. 467-473 
    Details
    ISSN: 1435-1536
    Keywords: Key words Block copolymers ; micelle ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract  The association behaviour of triblock copoly(ethylene oxide/tetrahydrofuran/ethylene oxide), in particular E100T27E100, in aqueous solutions has been investigated by means of static and dynamic light scattering, nuclear magnetic reso-nance (NMR) and surface tension techniques. On raising the polymer concentration at room temperature, the copolymer aggregates to form micelles with an aggregation number of about 105 (R G, mic≈15 nm and R H, mic≈13 nm, as revealed by light scattering and FT-PGSE NMR measurements, respectively). The micelles are kinetically quite stable, the micellar lifetime is shown to be more than 1 h. The residence time of a single unimer in a micelle is more than 140 ms. The apparent radius of gyration R G, mic is fairly independent of concentration, but large effects are observed on varying the temperature. Raising the temperature initially results in an increase of the apparent micellar size, followed by a maximum at an intermediate temperature (≈45 °C). At higher temperatures a contraction of the micelles is observed. The shape of the micelles also appear to vary in this temperature interval. The interactions responsible for these phenomena are discussed in terms of, e.g., the temperature-dependent solubility of the alkylene oxide segments in water and polydispersity effects.
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    URL: http://dx.doi.org/10.1007/s003960050105
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    Low ambient temperature decreases cadmium accumulation in the liver and kidneys of the bank vole (Clethrionomys glareolus) (1996)
    Springer
    BioMetals 9 (1996), S. 363-369 
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    ISSN: 1572-8773
    Keywords: cadmium ; copper ; iron ; photoperiod ; temperature ; zinc
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The importance of photoperiod and ambient temperature on the accumulation of cadmium in the liver and kidneys of bank voles was determined in the present study. Males and females, aged 1 month, were given 3.0 μg Cd ml−1 drinking water and divided into four groups according to photoperiod (16 h light/8 h dark and 8 h light/16 h dark) and ambient temperature (20 or 5°C); liver and kidneys were removed for cadmium as well as copper, iron and zinc analyses at the end of 6 weeks. Bank voles exposed to 5°C in both photoperiods consumed approximately 30% less water containing cadmium than those kept at 20°C. However, the total accumulation of cadmium in the liver and kidneys of males and females exposed to the low temperatures was 4.3–4.8 and 2.2–3.3 times less than that in animals maintained at room temperature in the long and short photoperiod, respectively. Simultaneously, the low temperature brought about an increase in the copper concentrations in the liver (12–43%) and kidneys (47–78%), giving rise to an inverse correlation between the cadmium accumulation and the tissue copper concentration. In contrast to cadmium and copper, the concentrations of iron and zinc were affected primarily by photoperiod. These findings indicate that ambient temperature is an important determinant of cadmium retention in the bank vole. It appears that low temperature decreases tissue cadmium accumulation not only by reducing cadmium intake but also through changes in copper metabolism.
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    Role of plant volatiles in the search for a host by parasitoidDiglyphus isaea (Hymenoptera: Eulophidae) (1996)
    Springer
    Journal of chemical ecology 22 (1996), S. 541-558 
    Details
    ISSN: 1573-1561
    Keywords: Parasites ; volatile signals ; synomone ; host detection ; Hymenoptera ; Eulophidae ; Diglyphus isaea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Diglyphus isaea Walker is a larval ectoparasitoid used in biological pest control against the American serpentine leaf minerLiriomyza trifolii Burgess. We studied the parasitoid's host searching behavior, using olfactometric methods. Our data show that the parasitoids locate host larvae (a leafmining dipteran) on the basis of volatile signals released by the plant-host complex. FemaleD. isaea are strongly attracted to the odors arising from damaged bean plants, whereas they show practically no response to intact plants. The results of our chemical analyses showed that about 15 components were present, two of which,cis-3-hexen-1-ol and 4-hydroxy-4-methyl-2-pentanone, were present in significantly larger quantities in the leaf extracts from mined or damaged bean plants than in those from healthy plants. The damage inflicted by the host larvae on these plants triggers the release of larger amounts of these substances, which probably lead the parasites to their hosts. The compounds thus act as synomones.
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    Sex pheromone of aphid parasitoidPraon volucre (Hymenoptera, Braconidae) (1996)
    Springer
    Journal of chemical ecology 22 (1996), S. 1169-1175 
    Details
    ISSN: 1573-1561
    Keywords: Hymenoptera ; aphid ; parasitoid ; sex ; pheromone ; GC ; EAG ; behavior
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Mating in the aphid parasitoidPraon volucre is mediated by a female-produced sex pheromone, which laboratory behavioral studies suggest is released from the abdomen. Gas chromatography coupled with electrophysiological and behavioral assays on males showed one area of activity in an air entrainment sample of virgin females. However, levels of pheromone production are very low and this has so far precluded its identification.
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    Sex recognition inDiglyphus isaea walker (Hymenoptera: Eulophidae): Role of an uncommon family of behaviorally active compounds (1996)
    Springer
    Journal of chemical ecology 22 (1996), S. 2063-2079 
    Details
    ISSN: 1573-1561
    Keywords: Hymenoptera ; Eulophidae ; Diglyphus isaea ; courtship behavior ; contact pheromones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The sexual behavior of the ectoparasitoidDiglyphus isaea is described. Recognition of the female by the male occurs at close range. Males initiate courtship behavior in the presence of a living female regardless of age, as well as in the presence of a female killed by freezing. Courtship behavior is not observed in the presence of a dead female washed with organic solvents but could be elicited using a lure covered with a female organic extract. These findings demonstrate that each sex develops a specific chemical signature that can be dissolved in hexane and transferred to a lure. Analysis of organic extracts by gas chromatography revealed chemical dimorphism between the two sexes. Gas chromatography coupled with mass spectrometry showed that the main components in females were esters of medium-chain fatty acids and long-chain 11-alcohols. There were few hydrocarbons. Female esters, which were present in only small proportions in males, were recovered in the nonhydrocarbon fraction obtained after fractionation of the total extract on a silica-filled microcolumn as a mixture containing 11-heneicosyl, 11-docosyl, 11-tricosyl, 11-tetracosyl, and 11-pentacosyl octanoate, and 11-docosyl, 11-tricosyl, 11-tetracosyl, and 11-pentacosyl decanoate. These results demonstrate that there is a specific gender-related chemical signature.
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    Volatile infochemicals used in host and host habitat location byCotesia flavipes Cameron andCotesia sesamiae (Cameron) (Hymenoptera: Braconidae), larval parasitoids of stemborers on graminae (1996)
    Springer
    Journal of chemical ecology 22 (1996), S. 307-323 
    Details
    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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    Ion association of dilute aqueous sodium hydroxide solutions to 600°C and 300 MPa by conductance measurements (1996)
    Springer
    Journal of solution chemistry 25 (1996), S. 711-729 
    Details
    ISSN: 1572-8927
    Keywords: Conductivity ; aqueous ; sodium hydroxide ; ion association ; temperature ; pressure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The limiting molar conductances Λ0 and ion association constants of dilute aqueous NaOH solutions (〈0.01 mol-kg−1) were determined by electrical conductance measurements at temperatures from 100 to 600°C and pressures up to 300 MPa. The limiting molar conductances of NaOH(aq) were found to increase with increasing temperature up to 300°C and with decreasing water density ρw. At temperatures ≥400°C, and densities between 0.6 to 0.8 g-cm−3, Λ0 is nearly temperature-independent but increases linearly with decreasing density, and then decreases at densities 〈0.6 g-cm−3. This phenomenon is largely due to the breakdown of the hydrogen-bonded, structure of water. The molal association constants K Am for NaOH( aq ) increase with increasing temperature and decreasing density. The logarithm of the molal association constant can be represented as a function of temperature (Kelvin) and the logarithm of the density of water by $$\begin{gathered} log K_{Am} = 2.477 - 951.53/T - (9.307 \hfill \\ - 3482.8/T)log \rho _{w } (25 - 600^\circ C) \hfill \\ \end{gathered} $$ which includes selected data taken from the literature, or by $$\begin{gathered} log K_{Am} = 1.648 - 370.31/T - (13.215 \hfill \\ - 6300.5/T)log \rho _{w } (400 - 600^\circ C) \hfill \\ \end{gathered} $$ which is based solely on results from the present study over this temperature range (and to 300 MPa) where the measurements are most precise.
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    Modeling the temperature response of nitrification (1996)
    Springer
    Biogeochemistry 35 (1996), S. 433-445 
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    ISSN: 1573-515X
    Keywords: ammonium oxidation ; growth rate ; maintenance energy ; modeling ; nitrification ; soil nitrate ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract To model nitrification rates in soils, it is necessary to have equations that accurately describe the effect of environmental variables on nitrification rates. A variety of equations have been used previously to describe the effect of temperature on rates of microbial processes. It is not clear which of these best describes the influence of temperature on nitrification rates in soil. I compared five equations for describing the effects of temperature on nitrification in two soils with very different temperature optima from a California oak woodland-annual grassland. The most appropriate equation depended on the range of temperatures being evaluated. A generalized Poisson density function best described temperature effects on nitrification rates in both soils over the range of 5 to 50 °C; however, the Arrhenius equation best described temperature effects over the narrower range of soil temperatures that normally occurs in the ecosystem (5 to 28 °C). Temperature optima for nitrification in most of the soils were greater than even the highest soil temperatures recorded at the sites. A model accounting for increased maintenance energy requirements at higher temperatures demonstrates how net energy production, rather than the gross energy production from nitrification, is maximized during adaptation by nitrifier populations to soil temperatures.
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    PGSE-NMR studies of solvent diffusion in poly(N-isopropylacrylamide) colloidal microgels (1995)
    Springer
    Colloid & polymer science 273 (1995), S. 405-411 
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    ISSN: 1435-1536
    Keywords: NMR diffusion ; solvent diffusion ; hydrogels ; microgels ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The solvent self-diffusion coefficient has been studied in thermoshrinking poly(N-isopropyl acrylamide) microgel dispersions by the pulsed-gradient spin-echo PGSE-NMR technique, as a function of temperature and mass fraction. After suitable corrections for the temperature, the H2O/D2O ratio and the relative volume fractions, all the self-diffusion data obtained over a temperature range of approximately 40 °C and mass fraction (2–12 % wt/wt) could be superimposed with the volume fraction as the universal factor. The observed reduction in the solvent self-diffusion coefficient with volume fraction was greater than that predicted by simple obstruction theory. After correction for-, and the subsequent removal of the obstruction effect, the diffusion of the solvent through the core of the particle is elucidated. As found for other polymer-solvent systems, there were no specific binding effects. The diffusion of the solvent in these dispersions over such temperature and mass fraction ranges could be rationalised assuming a constant solvent self-diffusion coefficient in the core of the particles.
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    Characterization of a twin-torch transferred dc arc (1995)
    Springer
    Plasma chemistry and plasma processing 15 (1995), S. 309-331 
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    ISSN: 1572-8986
    Keywords: Transferred arc ; voltage-current characteristic ; inhomogeneous plasma ; optical emission spectroscopy ; electron density ; temperature ; spatial distribution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Technology
    Notes: Abstract The results of a twin-torch transferred de arc .study are presented. The arc system consists of two torches of opposite polarity, and a coupling zone of plasma jets located between them. The torch configuration increases the system reliability and efficiency during material plasma processing. The results of the study present data for the voltage-current characteristics, general behavior of the twin-torch arc, and spatial distribution of the plasma parameters. The plasma parameters have been measured using optical emission spectroscopy for a 200 A (20 k W) do arc, at atmospheric pressure, with argon and nitrogen introduced as plasma forming gases into the anode and the cathode units, respectively. The measurement technique used has allowed the determination of local electron density and temperature values in an inhomogeneous plasma volume having no axial sysmmetry. The data obtained illustrate the novel features of the twin-torch transfrred do arc for its applications in plasma processing.
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    Hydrogen/argon plasma jet with methane addition (1995)
    Springer
    Plasma chemistry and plasma processing 15 (1995), S. 333-351 
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    ISSN: 1572-8986
    Keywords: Hydrogen/argon plasma ; methane ; do arc jet ; atmospheric pressure ; optical emission spectroscopy ; temperature ; density ; spatial distribution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Technology
    Notes: Abstract Spatial distributions of plasma parameters are presented for a H2/Ar plasma jet with addition of methane. The plasma has been generated at atmospheric pressure by a 200 A (20 kW) nontransferred do arc. Optical emission spectroscopy has been used for the measurements assuming the plasma jet to be optically thin and to have an axial symmetry. Local spectral ernissivity values have been evaluated using a routine Abel inversion procedure. Half- width and emissivity of Hβ spectral line have been measured to determine the electron density and temperature of the plasma. The densities of excited C, CH radicals have been evaluated from the absolute emissivities of relevant molecular emission bands measured in limited spectral intervals in the visible spectrum. The emissivity ratios have been used to fund rotational and vibrational temperatures. The results supply information on methane decomposition and the behavior of molecular radicals in close-to-thermal plasma jets.
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    Mechanism underlying cuticular hydrocarbon homogeneity in the antCamponotus vagus (SCOP.) (Hymenoptera: Formicidae): Role of postpharyngeal glands (1995)
    Springer
    Journal of chemical ecology 21 (1995), S. 1127-1148 
    Details
    ISSN: 1573-1561
    Keywords: Cuticular hydrocarbons ; chemical signature ; postpharyngeal glands ; nestmate recognition ; Hymenoptera ; ant ; Camponotus vagus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The aim of the present study was to investigate the regulation and the homogeneity of the chemical signature between members ofCamponotus vagus after experimentally changing the cuticular chemical signature by topically applying hydrocarbons. Topical application of pentane (solvent) to the cuticle of isolated workers led to a significant decrease in the quantities of the cuticular hydrocarbons measured within 3 hr, followed by an increase within the following 3 hr and a period of relative stability from 9 hr to 14 days. On the other hand, after topical application to isolated workers ofn-tetracosane, a hydrocarbon existing only in trace quantity in this species, the quantity of this hydrocarbon measured over time in the epicuticular wax tended to level out at about 14 days after treatment. In contrast, topically applied (Z)-9-tricosene, an unsaturated hydrocarbon not normally synthesized by this species, decreased dramatically within a few hours and had completely disappeared within 14 days. (Z)-9-Tricosene applied to one member of a group was present in the postpharyngeal glands of the other members from 30 min to seven days of cohabitation. The highest levels were recorded in all six workers in each group after one day. GC-MS analyses showed that (Z)-9-tricosene was present in the cuticles of some untreated workers only after four and seven days of cohabitation with a treated worker. These data suggest: (1) that the deposited (Z)-9-tricosene decreased very quickly on the cuticle of the treated worker, although the total amount was spread over the cuticle and postpharyngeal gland and (2) that it was absorbed by the nontreated workers via the postpharyngeal glands during licking or grooming activities and reincorporated into the cuticle at four and seven days. When the treated worker was separated from the other ants by a wire mesh, (Z)-9-tricosene was detected neither in the cuticle nor in the postpharyngeal gland of nontreated workers.
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    Alkadienes mediating courtship in the parasitoidCardiochiles nigriceps (Hymenoptera: Braconidae) (1995)
    Springer
    Journal of chemical ecology 21 (1995), S. 1971-1989 
    Details
    ISSN: 1573-1561
    Keywords: Cardiochiles nigriceps ; parasitoid ; Hymenoptera ; Braconidae ; pheromone ; mating ; courtship ; hydrocarbon ; cuticle ; alkadienes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Courtship inCardiochiles nigriceps (Viereck) (Hymenoptera: Braconidae) involves male attraction to females and male antennation of females followed by mounting and copulation. Once the female is located, antennation and mounting of the female are mediated by the hydrocarbon fraction of female's Dufour's gland and cuticle. The identification of the cuticular hydrocarbons of males and females revealed a mixture of alkanes and alkenes, in addition to a series of alkadienes specific to females. These female-specific alkadienes reported from Braconidae are unusual among insect alkadienes in that the second double bond occurs in the middle of the molecule. Bioassays with three available alkadienes revealed that contact behaviors (antennation and mounting) are in part mediated by the (Z,Z)-7, 13-heptacosadiene and at least one other alkadiene in combination with other hydrocarbons found in males and females.
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    Why not be a queen? Regioselectivity in mandibular secretions of honeybee castes (1995)
    Springer
    Journal of chemical ecology 21 (1995), S. 1017-1029 
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    ISSN: 1573-1561
    Keywords: Hymenoptera ; Apidae ; Apis mellifera L. ; mandibular gland secretion ; hydroxydecenoic acids ; hydroxydecanoic acids ; deuterated precursors ; gas chromatography-mass spectroscopy ; biosynthetic precursors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Both female castes of the honeybee (Apis mellifera L.) synthesize hydroxylated 2(E)-decenoic acids in their mandibular glands. Queens produce 9-hydroxy-2(E)-decenoic acid as part of their primer pheromone, while workers produce the regioisomeric 10-hydroxy acid, probably as a larval food source and an antiseptic secretion. Both workers and queens are biosynthetically competent to produce the other caste's dominant hydroxylated compound, as both isomers can be detected in queens and workers. We investigated the source of the caste-determined regioselectivity of hydroxy acid biosynthesis by investigating the production and interconversion of these compounds in isolated worker honeybee mandibular glands with specifically deuterated precursors. Gas chromatographic-mass spectroscopic identification of the labeled product indicates that octadecanoic acid is converted into 10-hydroxy-2(E)-decenoic acid with higher efficiency than either hexadecanoic or decanoic acids. 10-Hydroxydecanoic acid is readily converted into 10-hydroxy-2(E)-decenoic acid as expected in the β-oxidation process. The saturated and unsaturated 10-hydroxy acids are oxidized to the corresponding ten carbon diacids.
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    Excess volumes of binary mixtures of ethylbenzene with octanol, nonanol and dodecanol from 50 to 100°C and 0.1 to 7.5 MPa (1995)
    Springer
    Journal of solution chemistry 24 (1995), S. 153-170 
    Details
    ISSN: 1572-8927
    Keywords: Densities ; excess volume ; pressure ; temperature ; ethylbenzene ; octanol ; nonanol ; dodecanol ; order creation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The excess volume V E of binary mixtures of octanol, nonanol and dodecanol in ethylbenzene have been calculated from the densities measured with a vibrating tube densimeter at temperatures from 50 to 100 °C and at pressures from 0.1 to 7.5 MPa. The values of V E are positive for all the three mixtures in the complete temperature, pressure and mole fraction ranges studied. The maxima in V E is observed at 0.4 mole fraction of alkanol. The results are discussed in terms of specific interactions present in the binary mixtures. The second order thermodynamic quantities (∂V E /∂T)p,(∂V E /∂P)T and (∂V E /∂P)T which have been derived from the effect of temperature and pressure on V E , indicate an overall net creation of order in the binary mixtures of ethylbenzene with higher homologues of alkanols.
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    Electrical conductances of aqueous sodium trifluoromethanesulfonate from 0 to 450°C and pressures to 250 MPa (1995)
    Springer
    Journal of solution chemistry 24 (1995), S. 753-769 
    Details
    ISSN: 1572-8927
    Keywords: Conductivity ; sodium trifluoromethanesulfonate ; ion association ; temperature ; pressure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The electrical conductances of dilute (0.001 to 0.1 mol-kg−1) aqueous sodium trifluoromethanesulfonate (NaCF3SO3) solutions have been measured from 0 to 450°C and pressures to 250 MPa. The limiting molar conductance $$\Lambda _0 $$ increases with increasing temperature from 0 to 300°C and decreasing density from 0.8 to 0.3 g-cm−3. Above 300°C, $$\Lambda _0 $$ is nearly temperature independent, but increases linearly with decreasing density. The logarithm of the molal association constant of NaCF3SO3 calculated at temperatures from 372 to 450°C is represented as a function of temperature (Kelvin) and density of water (g-cm−3) by $$\log K_m = 0.888 - 330.4/T - (12.83 - 5349/T)\log \rho _w $$ The relative strengths of NaCF3SO3 and NaCl are similar within the accuracy of the current measurements over the limited range of temperature and pressure that could be investigated here.
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    Comparative analysis of steam distilled floral oils of cacao cultivars (Theobroma cacao L., Sterculiaceae) and attraction of flying insects: Implications for aTheobroma pollination syndrome (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 2687-2703 
    Details
    ISSN: 1573-1561
    Keywords: Floral oils ; cacao ; Theobroma cacao ; Sterculiaceae ; attraction ; Diptera ; Ceratopogonidae ; Cecidomyiidae ; Hymenoptera ; Apidae ; pollination ; 1-pentadecene ; n-pentadecene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Steam-distilled floral fragrance oils from nine distinctive cultivars ofTheobroma cacao L. (Sterculiaceae) in Costa Rica were examined with GC-MS to determine whether or not major differences existed among these cultivars for volatile constituents comprising 50% or more of the samples. The cultivars selected for floral oil analyses were chosen to represent diverse cultivars having supposedly different genetic backgrounds and histories of artificial selection for agronomic purposes. Cluster analysis revealed two major groupings of cultivars: those with higher molecular weight dominant compounds, and those having lower molecular weight compounds. Additionally, one cultivar, Rim-100, selected from criollo or ancestral-type cacao in Mexico and resembling criollo in the appearance of flowers and fruits, formed an extreme group having the highest molecular weight profile for major volatile compounds. Based upon these analyses, bioassays using McPhail traps were performed in an abandoned cacao plantation in northeastern Costa Rica during rainy and dry seasons to determine the relative attraction of these oils to flying insects. Bioassays revealed that the Rim-100 cultivar attracted by far the greatest numbers of cacao-associated midges (Diptera: Ceratopogonidae and Cecidomyiidae), as well as stingless bees (Hymenoptera: Apidae: Meliponinae), suggesting that a floral fragrance having high-molecular-weight volatiles is more potent as an attractant to flying insects than floral oils having lower-molecular-weight compounds. It is suggested that Rim-100 more closely resembles an ancestral or wild-type cacao than the other cultivars examined, and therefore it is more effective in attracting opportunistic dipteran floral visitors and pollinators than other cultivars in plantation settings. Several of the major volatile compounds found in the floral oils ofT. cacao and other species ofTheobroma occur in mandibular and other exocrine glands in various bees, including stingless bees and halictids, known visitors ofTheobroma flowers. These compounds are particularly present in noncultivated species ofTheobroma and have much more noticeable fragrances than the seemingly scentless flowers of cultivatedT. cacao selected for agriculture. It is hypothesized that the floral attraction system of ancestral or wild (noncultivated)T. cacao and other species ofTheobroma may have evolved to attract certain bees as their principal pollinators in natural habitats in the Neotropics, with a floral reward hypothesized as being sociochemicals needed by bees for mating, foraging, territorial defense, etc. Because of the many generations of extensive selection by cloning for desired cultivars,T. cacao might have lost much of its original floral attraction system for bees, instead being pollinated opportunistically by dipterans in plantation habitats. This may help to explain why natural pollination in cultivatedT. cacao is generally very poor relative to observed levels of fruit-set in wild or noncultivated species ofTheobroma.
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    Interactions betweenAlloxysta brevis (Hymenoptera, Cynipoidea, Alloxystidae) and honeydew-collecting ants: How an aphid hyperparasitoid overcomes ant aggression by chemical defense (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 2901-2915 
    Details
    ISSN: 1573-1561
    Keywords: Hymenoptera ; Alloxystidae ; hyperparasitoids ; ants ; Formicidae ; interactions ; aggression ; chemical defense ; 6-methyl-5-hepten-2-one ; actinidin ; biological significance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Foraging females of the aphid hyperparasitoidAlloxysta brevis were attacked by honeydew-collecting workers of the antLasius niger at the first encounter. However, ants abandoned their attacks quickly, and foragingA. brevis remained unmolested for a subsequent time interval of approximately 5 min, which is long enough for the hyperparasitoid to oviposit successfully. Furthermore, freshly killed intactA. brevis were disregarded by ants, while decapitated specimens were readily removed. We present evidence thatA. brevis females release a mandibular gland secretion, which contains 6-methyl-5-hepten-2-one, actinidin, and unidentified iridoids, in response to an ant attack. This secretion functions both as a measure of self-defense if the female is seized by an ant worker and as a repellent, which prevents ant attacks during subsequent encounters. This is the first evidence for chemical defense in a hymenopterous parasitoid. It enablesA. brevis females to hyperparasitize ant-attended aphids that constitute a major proportion of their hosts and significantly reduces mortality by ectohyperparasitoids.
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    Biological activity of (3R,5S,6R)- and (3S,5R,6S)-3,5-dimethyl-6-(methylethyl)-3,4,5,6-tetrahydropyran-2-one, a pheromone ofMacrocentrus grandii (Goidanich) (Hymenoptera: Braconidae) (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 3373-3380 
    Details
    ISSN: 1573-1561
    Keywords: Pheromone ; 3,5-dimethyl-6-(methylethyl)-3,4,5,6-tetrahydropyran-2-one ; enantiomer ; parasitoid ; Macrocentrus grandii ; Hymenoptera ; Braconidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract In a previous study we reported identification of (3R*,5S*,6R*)-3,5-dimethyl-6-(methylethyl)-3,4,5,6-tetrahydropyran-2-one as a component of the pheromone ofMacrocentrus grandii Goidanich. The lactone was present in male and female wasps, and laboratory and field bioassays demonstrated that both sources of the lactone elicit flight initiation, upwind anemotaxis, and casting in male wasps. In the present study, the synthetic (3R,5S,6R)- and (3S,5R,6S)-lactone enantiomers (RSR andSRS, respectively) were bioassayed for biological activity. In wind tunnel studies theSRS enantiomer elicited flight initiation, upwind anemotaxis, and casting by male wasps comparable to lactone derived from male and female wasps. Flight response to theRSR enantiomer averaged 14 percent of theSRS enantiomer. No specific ratio of the stereoisomers was found more attractive than theSRS enantiomer alone. Field studies demonstrated theSRS enantiomer was active alone in attracting male wasps. When paired with (Z)-4-tridecenal (a previously identified female-derived sex pheromone), theSRS enantiomer yielded a synergistic response comparable to (Z)-4-tridecenal plus female-derived lactone.
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    Volatile secretions of old world army antAenictus rotundatus and chemotaxonomic implications of army ant dufour gland chemistry (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 3297-3305 
    Details
    ISSN: 1573-1561
    Keywords: Hymenoptera ; Formicidae ; army ants ; Dorylinae ; Aenictus ; Dorylus ; Eciton ; Ecitoninae ; Dufour gland ; mandibular gland ; postpygidial gland ; ant secretions ; chemotaxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The Dufour glands ofAenictus rotundatus contain a complex mixture of terpenoids with geranylgeraniol comprising over 50% of the secretion. Some novel compounds have been tentatively identified as higher homologs of 1,3,3-trimethyl-2,7-dioxabicyclo[2,2,1]heptane based on GC-MS data. The Dufour gland secretion ofA. rotundatus is more similar in composition to the secretions of members of the subfamily Ecitoninae than to its closer relatives from the tribe Dorylini, a result that further complicates studies on the phylogeny of army ants. The mandibular glands ofA. rotundatus contain a mixture of 4-methyl-3-heptanone and limonene in trace amounts, and the well-developed postpygidial glands contain methyl anthranilate only.
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    Responses of fig wasps to host plant volatile cues (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 785-802 
    Details
    ISSN: 1573-1561
    Keywords: Hymenoptera ; Agaonidae ; evolution ; fig wasps ; host finding ; volatile attractants ; Ficus ; Moraceae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Fig wasps (Chalcidoidea; Agaonidae) are intimately associated with the 750 or so species of fig trees (Ficus, Moraceae). Each tree species is usually pollinated by a single species of wasp belonging to the subfamily Agaoninae, while other wasps of the family are parasitoids or seed predators. Previous experiments have shown that the wasps are attracted to the trees by volatiles emanating from the figs. Using fig-bearing trees and arrays of sticky traps baited with figs, we investigated the specificity of wasp attraction and its timing. The pollinators of two closely relatedFicus species were specifically attracted to figs of their host species and only at the time when figs were ready to be pollinated. Some nonpollinating fig wasps appear to respond to the same volatile cues.
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    Attraction of reproductive honey bee swarms to artificial nests by Nasonov pheromone (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 1053-1056 
    Details
    ISSN: 1573-1561
    Keywords: Honey bee ; Apis mellifera ; Hymenoptera ; Apidae ; pheromone ; attractant ; Nasonov ; swarms ; citral ; geraniol ; nerolic acid ; geranic acid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A crossover experimental design was established to test the attractancy of Nasonov pheromone to reproductive swarms of honey bees. Nineteen swarms were attracted to artificial nest cavities containing a slow-release blend of the Nasonov components citral, geraniol, and nerolic + geranic acids, and only four swarms were attracted to pheromone-free artificial nests. The results indicate that Nasonov pheromone plays a key role in the attraction of honey bee swarms to nest cavities.
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    Responses by amphisbaenianBlanus cinereus to chemicals from prey or potentially harmful ant species (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 1113-1119 
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    ISSN: 1573-1561
    Keywords: Hymenoptera ; Formicidae ; Reptilia ; Amphisbaenidae ; Blanus cinereus ; prey odor ; harmful prey ; tongue-flicking
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract We tested the ability of amphisbaenians (Blanus cinereus) to discriminate between odors of ant species selected as prey (Pheidole pallidula) and odors of potentially harmful ant species (Messor barbarus) that are avoided. Tongue-flick rate to swabs impregnated with ant odors, cologne, or deionized water differed among treatments, showing that amphisbaenians were able to discriminate ant species odors. Amphisbaenians showed an aggressive response and bit applicators bearing the odor of harmful ants, while the odor of prey ants did not elicit bites to swabs. The possible evolutionary advantage of identifying and avoiding harmful ants is discussed in relation to the fossoriality of amphisbaenians.
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    Cuticular hydrocarbons of the paper wasp,Polistes fuscatus: A search for recognition pheromones (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 1677-1687 
    Details
    ISSN: 1573-1561
    Keywords: Polistes fuscatus ; Hymenoptera ; Vespidae ; cuticular hydrocarbons ; discriminant function analysis ; nestmate recognition ; social wasps
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The cuticular chemicals of 124 individual wasps (foundresses and workers) from 23 colonies ofPolistes fuscatus were analyzed. The compounds identified, all of which were hydrocarbons, were similar to those of other vespid wasps in that the bulk of the hydrocarbons were 23–33 carbons in chain length. However, the hydrocarbon profile ofP. fuscatus differed from those of its congeners in its proportions of straight-chain alkanes, methylalkanes, and alkenes. Three of the 20 identified hydrocarbons, 13- and 15-MeC31, 11,15- and 13,17-diMeC31, and 13-, 15-, and 17-MeC33, had properties postulated for recognition pheromones: colony specificity, efficacy in assigning wasps to the appropriate colony, heritability, lack of differences between foundresses and workers, and distinctive stereochemistry.
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    Trail pheromone of leaf-cutting antAcromyrmex subterraneus subterraneus (Forel) (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 1719-1724 
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    ISSN: 1573-1561
    Keywords: Trail pheromone ; Hymenoptera ; Formicidae ; methyl 4-methylpyrrole-2-carboxylate ; poison gland
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The trail pheromone ofAcromyrmex subterraneus subterraneus consists simply of the heterocyclic ester methyl 4-methylpyrrole-2-carboxylate in the venom reservoir of workers at about 1.2 ng/ant. No pyrazines were detected, and no enhancement of trail-following was observed when pyrazines were added to the pyrrole compound.
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    Plant-natural enemy association in the tritrophic system,Cotesia rubecula-Pieris rapae-brassiceae (cruciferae): I. Sources of infochemicals (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 1725-1734 
    Details
    ISSN: 1573-1561
    Keywords: Cotesia rubecula ; Hymenoptera ; Braconidae ; Lepidoptera ; Pieridae ; Plutellidae ; Pieris rapae ; Brassica oleracea ; Plutella xylostella ; Phaselus vulgaris ; Geranium molle ; tritrophic interactions ; infochemicals ; volatiles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The role of airborne infochemicals in host selection by the parasitoidCotesia rubecula (Marshal) (Hymenoptera: Braconidae) was examined in a wind tunnel. To elucidate the role of volatile chemicals in attractingC. rubecula to cabbage infested by the host [Pieris rapae L. (Lepidoptera: Pieridae)], the potential sources of volatiles related toP. rapae infestation on cabbage were tested individually. The responses of females to nonhost plant species, bean and geranium, as well as to frass of a nonhost lepidopteran were also examined.C. rubecula was attracted to cabbage previously infested byP. rapae and to frass and regurgitate ofP. rapae. No attraction was observed to larvae ofP. rapae alone. Females were also attracted to mechanically damaged cabbage, cabbage previously infested byPlutella xylostella L. (Lepidoptera: Plutellidae) (a nonhost lepidopteran herbivore), and cabbage previously infested by snails (a nonhost, noninsect herbivore). Intact cabbage, bean, and geranium plants elicited no attraction. A low frequency of attraction was observed to mechanically damaged bean and geranium. Attraction was also observed to frass ofP. xylostella. Volatiles from cabbage related to damage, and volatiles from frass and regurgitate of the host seem to play an important role in guidingC. rubecula to plants infested by its host.
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    Natural and synthetic oviposition stimulants forCatolaccus grandis (Burks) females (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 1583-1594 
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    ISSN: 1573-1561
    Keywords: Ovipositional stimulants ; Catolaccus grandis ; Hymenoptera ; Pteromalidae ; short-chain hydrocarbons ; artificial diet ; kairomones ; synomones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Oviposition behavior was elicited fromCatolaccus grandis (Burks) (Hymenoptera: Pteromalidae) females, an ectoparasitoid of the boll weevil,Anthonomus grandis Boheman (Coleoptera: Curculionidae), by smears of freshly cut cotton bolls or smears of extracts prepared with boll weevil damaged or undamaged cotton boll tissues. Oviposition behavior was also elicited fromC. grandis females by smears made withn-pentane,n-hexane,n-heptane, and isooctane. This is the first report of oviposition behavior elicited for any parasitoid by these short-chain saturated hydrocarbons (alkanes), introducing a new concept on the chemical mediation of parasitoid behavior during host selection. Oviposition behavior was also elicited fromC. grandis females by volatiles emanating from an artificial diet devoid of insect components that was specifically developed for the in vitro rearing of ectoparasitoids. The possible use of a synergistic combination ofn-hexane and diet to optimize the mechanized production of noncontaminated eggs is also discussed.
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    Cuticular lipid profiles of queens, workers, and males of social waspPolistes metricus say are colony-specific (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 2307-2321 
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    ISSN: 1573-1561
    Keywords: Polistes metricus ; Hymenoptera ; Vespidae ; cuticular hydrocarbons ; discriminant analysis ; nestmate recognition ; social wasps
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The cuticular lipids ofPolistes metricus queens, workers and males from seven laboratory-maintained colonies were extracted and analyzed by combined gas chromatography-mass spectrometry. Males had higher proportions of alkenes (20.5%) in their cuticular lipids than did queens (2.3%) or workers (7.7%). Discriminant analyses of the cuticular lipid profiles of the adult wasps showed that males group separately from females. Additional analyses showed that queens group with their respective workers by colony and that queens group even more closely with males by colony. The most distinct groupings occurred with workers only by colony and with males only by colony. Stepwise discriminant analyses showed that each type of grouping was dependent upon a different combination of cuticular lipids.
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    Discrimination of oilseed rape volatiles by honey bee: Novel combined gas chromatographic-electrophysiological behavioral assay (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 3221-3231 
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    ISSN: 1573-1561
    Keywords: Honey bee ; Apis mellifera ; Hymenoptera ; Apidae ; gas chromatography ; electroantennogram ; conditioned proboscis extension ; olfactory discrimination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A novel technique for the simultaneous monitoring of electroan-tennogram (EAG) and conditioned proboscis extension (CPE) responses of honey bees to the effluent from a gas chromatograph (GC) was developed to locate biologically active components in blends of plant volatiles and to investigate odor recognition at the peripheral and behavioral levels. A six-component mixture, comprising compounds previously identified as oilseed rape floral volatiles, was used as the stimulus. Standard CPE and EAG recordings were done as a reference. EAG responses were elicited from unconditioned bees by all the components presented either in the coupled or the standard mode. Conditioned bees gave larger EAG responses than unconditioned bees, suggesting that antennal sensitivity is enhanced by conditioning. At the behavioral level, in both the standard and the coupled modes, only conditioned bees showed the proboscis extension response, with the majority of individuals responding to linalool, 2-phenylethanol, and benzyl alcohol.
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    Sequestration ofVeratrum alkaloids by specialistRhadinoceraea nodicornis konow (Hymenoptera, Tenthredinidae) and its ecoethological implications (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 3233-3250 
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    ISSN: 1573-1561
    Keywords: Veratrum album ; ceveratrum alkaloids ; plant-insect interactions ; sequestration ; hemolymph ; feeding deterrence ; Rhadinoceraea nodicornis ; Aglaostigma sp. ; Hymenoptera ; Tenthredinidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The larvae of the specialist sawflyRhadinoceraea nodicornis Konow (Hymenoptera, Tenthredinidae) store in their hemolymph ceveratrum alkaloids originating from the host plantVeratrum album L. (Liliales, Melanthiaceae). The major alkaloid found in the hemolymph is 3-acetyl-zygadenine. Qualitative and quantitative data showed that the plant alkaloid 3-angeloylzygadenine is most probably metabolized in the larval gut to zygadenine and then acetylated. A still unidentified alkaloid with a molecular weight of 591 Da was detected in plant leaves as well as in the gut, hemolymph, and excrement of larvae. Protoveratrine A and B, on the other hand, seem to be degraded by the larvae. These findings indicate that the pathway of ceveratrum alkaloids inR. nodicornis larvae is fourfold: direct sequestration, metabolism followed by sequestration, excretion of intact alkaloids, and degradation. In contrast, no ceveratrum alkaloids were detected in the hemolymph and excrement of larvae of the generalist sawflyAglaostigma sp. fed withV. album leaves. Bioassays with the antMyrmica rubra L. proved that the hemolymph ofR. nodicornis larvae is highly deterrent and toxic. In bioassays evaluating defensive efficiency against predators (ants, spiders, and bushcrickets), no larvae were eaten. Ceveratrum alkaloids were also detected in the hibernating prepupae ofR. nodicornis. In feeding bioassays, the shrewCrocidura russula Hermann rarely fed upon prepupae, suggesting that this stage is also protected from predation to some degree. In field surveys, the only parasitoids recorded were two ichneumonid species that are believed to be specialized onR. nodicornis. Bioassays and field observations enable us to suppose thatR. nodicornis and its enemies produce a food web of ion connectance.
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    Plant-natural enemy association in the tritrophic systemCotesia rubecula-Pieris rapae-brassicaceae (cruciferae): II. Preference ofC. rubecula for landing and searching (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 1735-1748 
    Details
    ISSN: 1573-1561
    Keywords: Cotesia rubecula ; Hymenoptera ; Braconidae ; Lepidoptera ; Pieridae ; Plutellidae ; Pieris rapae ; Plutella xylostella ; Helix aspera ; Brassica oleracea ; Phaseolus vulgaris ; tritrophic interactions ; synomones ; infochemicals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The responses of the parasitoidCotesia rubecula to differently damaged cabbages were recorded during a series of choice tests. To determine if flyingC. rubecula can discriminate differences in the blend of volatiles emitted by cabbages damaged by different causes and how plant volatiles released from a distant source affect the searching behavior ofC. rubecula once searching on a plant, wasps were presented with a choice of plants located one behind the other and separated by a distance of 15 cm. The sources of damage were: cabbage damaged by the host (Pieris rapae), by a nonhost lepidopteran herbivore (Plutella xylostella), by a nonhost, noninsect herbivore (snail), and by mechanical means. The results showed that the site of first landing and the time spent searching on the leaves was influenced by the type of damage inflicted on plants. Wasps preferred to land on cabbages damaged by host and nonhost species of Lepidoptera over those damaged by snails and mechanical means. No preference was observed for first landing between cabbages damaged by the two species of Lepidoptera or between cabbages damaged by snails and mechanical means. Cabbage damaged byP. rapae was searched most intensively, followed by cabbage damaged byP. xylostella, cabbage damaged by snails, and cabbage damaged by mechanical means.C. rubecula differentiates between the volatile blends emitted by differently damaged cabbages, and it is attracted to volatiles related to recent lepidopteran damage. Wasps searched longer on freshly damaged than on leaves with older damage.
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    Chemical composition of North American bee propolis and biological activity towards larvae of greater wax moth (Lepidoptera: Pyralidae) (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 1783-1791 
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    ISSN: 1573-1561
    Keywords: Galleria mellonella ; Apis mellifera ; Pyralidae ; Apidae ; Lepidoptera ; Hymenoptera ; greater wax moth ; honeybee ; propolis ; plant resins ; phenolics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Bee propolis is a sticky amalgamation of plant resins collected by honeybees (Apis mellifera L.) and used in the hive for filling cracks and repairing combs. Propolis contains a diversity of compounds of plant origin, and is reported to have medicinal, antimicrobial, insecticidal, and phytotoxic properties. We examined the physical and chemical composition of North American samples of bee propolis from several sites in North America and tested for bioactivity against larvae of the greater wax moth (Galleria mellonella L.), a common apiary pest. The amount of methanol-extractable resin in samples from Ohio and Georgia ranged from 24% to 79% by weight. Propolis collected from hives in Ohio was more chemically diverse (over 30 compounds detected by paper chromatography) than material from south Georgia (fewer than 10 major compounds) and contained a lower proportion of methanol-insoluble beeswax. The paper chromatographic surveys revealed little variation in the chemical profile of specific hives over a six-month period and no differences between propolis from adjacent hives. Four flavonoids were identified from propolis collected in Ohio: kaempferol, galangin, 3,3′-dimethoxyquercetin and 3-methoxykaempferol. When mixed into artificial diet, fractionated propolis reduced larval growth of the greater wax moth, but not dramatically. An array of phenolics reported from propolis (caffeic acid, chrysin, ferulic acid, galangin, kaempferol, and quercetin) were bioassayed individually for effects on larvae, but none reduced larval growth at the concentrations tested, suggesting that wax moths are tolerant of some phenolics in their diet.
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    Cuticle alkanes of honeybee larvae mediate arrestment of bee parasiteVarroa jacobsoni (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 2437-2453 
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    ISSN: 1573-1561
    Keywords: Varroa jacobsoni ; Acari ; Varroidae ; mite ; Apis mellifera ; Hymenoptera ; Apidae ; honeybee ; chemoreception ; host selection ; cuticle ; hydrocarbons ; alkanes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The ectoparasitic miteVarroa jacobsoni invades worker brood cells of the honeybeeApis mellifera during the last 20 hr before the cells are sealed with a wax cap. Cuticle extracts of 8-day-old worker honeybee larvae occupying such brood cells have an arrestment effect on the mite. The mites run for prolonged periods on the extract, systematically returning onto the stimulus after touching the borders of the treated area. Mites increase walking speed and path straightness in response to increasing doses of a nonpolar fraction of the cuticle extract. Saturated straight-chain odd-numbered C19–C29 hydrocarbons were identified by thin-layer argentation chromatography and gas chromatography-mass spectrometry as the most active constituents, with branched alkanes also contributing to the arrestment effect of this active fraction. Analysis of the behavior responses to syntheticn-alkanes indicate that the response is probably based on a synergism between the different alkane components of the fraction rather than to an individual compound.
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    Integumental slime and wax secretion: Defensive adaptations of sawfly larvae (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 2743-2749 
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    ISSN: 1573-1561
    Keywords: Hymenoptera ; Symphyta ; Tenthredinidae ; predation ; chemical defense ; ants ; Formicidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Evidence is presented from predation tests with ants (Formica exsectoides) that the slimy coating ofCaliroa cerasi and the waxy investiture ofEriocampa ovata serve in defense.
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    Cuticular hydrocarbons wherebyMessor barbarus ant workers putatively discriminate between monogynous and polygynous colonies. Are workers labeled by queens? (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 2985-3003 
    Details
    ISSN: 1573-1561
    Keywords: Chemical communication ; nestmate recognition ; role of the queen ; colony closure ; aggressive behavior ; pheromone ; cuticular hydrocarbons ; ant ; Messor barbarus ; Hymenoptera ; Formicidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The results of laboratory experiments carried out with both monogynous and artificially polygynousMessor barbarus ant colonies (which under natural conditions are always monogynous) have shown that the workers belonging to monogynous colonies were able to discriminate between intruders from other monogynous colonies and those from polygynous (di- and trigynous) ones. What mechanisms are involved in this discriminatory ability? Since differences in the relative proportions of the hydrocarbons they carry are known to convey complex messages that are used for recognition purposes, it was proposed here to investigate whether there existed any differences in the proportions of the various hydrocarbons carried by the diverse categories of intruders tested in our experiments. It emerged that one set of hydrocarbons, which were usually present in rather small proportions and included all the families that constitute this species' chemical signature (n-alkanes, mono-, di-, and trimethylalkanes), was characteristically associated with workers from monogynous colonies. Another set of hydrocarbons, which included some of the above components, mostly in larger relative proportions, can be said to have characterized the digynous and trigynous colonies.
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    Dermal gland secretions of tropical bont tick,Amblyomma variegatum (Acarina: Ixodidae): Biological activity on predators and pathogens (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 1495-1503 
    Details
    ISSN: 1573-1561
    Keywords: Amblyomma variegatum ; Acarina ; Ixodidae ; dermal glands ; Solenopsis geminata ; Hymenoptera ; Formicidae ; defensive secretion ; entomopathogenic bacteria ; antibiotic
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract When they are mechanically disturbed, all instars of the tropical bont tickAmblyomma variegatum exude droplets of a liquid on the dorsal, lateral, and ventral cuticle. These spread out and quickly evaporate. In this study, the possible role of these secretions was investigated in relation to predators and pathogens. In laboratory bioassays, it was demonstrated that the secretions from engorged larvae, nymphs, and females have an antibiotic activity against the bacteria speciesBacillus thuringiensis andSerratia marcescens, combined with a repellent effect on a potential predator, the fire-antSolenopsis geminata.
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    Plant-natural enemy association in tritrophic system,Cotesia rubecula-Pieris rapae-brassicaceae (Cruciferae). III: Collection and identification of plant and frass volatiles (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 1955-1967 
    Details
    ISSN: 1573-1561
    Keywords: Pieris rapae ; Lepidoptera ; Pieridae ; Plutellidae ; Plutella xylostella ; Cotesia rubecula ; Hymenoptera ; Braconidae ; Brassica oleracea capitata ; infochemicals ; plant volatiles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract To elucidate the identity of the volatile compounds that could be involved in the searching behavior of the parasitoidCotesia rubecula Marshall (Hymenoptera: Braconidae), the volatiles released by cabbage and frass of Lepidoptera feeding on cabbage were collected and analyzed using a gas chromatograph-mass spectrometer. The volatiles emitted by intact cabbage were α-pinene, β-pinene, myrcene, 1,8-cineole,n-hexyl acetate,cis-3-hexen-1-yl acetate, and dimethyl trisulfide. Mechanical damage on an intact plant induced the release of two more compounds,trans-2-hexenal and 1-methoxy-3-methylene-2-pentanone. Current feeding by larvae ofPieris rapae L. (Pieridae) induced the plant to release all the compounds released after mechanical damage and additionally 4-methyl-3-pentenal and allyl isothiocyanate. Current feeding by larvae ofPlutella xylostella L. (Plutellidae) induced the plant to release all the compounds present after mechanical damage and additionally allyl isothiocyanate. The volatiles emitted after feeding by the lepidopterans had ceased were the same as those emitted by cabbage damaged by mechanical means. The blend of volatiles emitted by frass was comprised of plant chemicals, mainly sulfur compounds. Frass ofP. rapae emitted allyl isothiocyanate, methyl isothiocyanate, methyl propyl sulfide, dimethyl trisulfide,S-methyl methane thiosulfinate, 4-methyl-3-pentenal,trans-2-hexenal, and 2,3-dihydro-4-methyl furan. Frass ofP. xylostella emitted only dimethyl trisulfide andS-methyl methane thiosulfinate. The blend of volatiles emitted by frass is herbivore-species specific.
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    Importance of phenolic glucosides in host selection of shoot galling sawfly,Euura amerinae, onSalix pentandra (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 2455-2466 
    Details
    ISSN: 1573-1561
    Keywords: Herbivory ; host preference ; host selection ; oviposition ; phenolic glucosides ; willow ; Salicaceae ; Salix ; galling sawfly ; Hymenoptera ; Tenthredinidae ; Euura amerinae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The effects of phenolic glucosides on the oviposition behavior ofEuura amerinae L. (Hymenoptera: Tenthredinidae) were tested in multiple oviposition experiments using different shoot length categories ofSalix pentandra L. (with different amounts of phenolic glucosides) and in experiments with pure phenolic glucosides (salidroside, arbutin, salicin, 90% salicortin, 90% 2′-O-acetylsalicortin) or composite total fractions of phenolic glucosides from three willow species (S. pentandra, S. myrsinifolia Salisb.,S. triandra L.). This was the first time that the effects of pure phenolic glucosides on the oviposition behavior of sawfly species were tested. Total fraction of phenolic glucosides fromS. pentandra and its main individual glucoside, 2′-O-acetyl-salicortin, stimulated the strongest ovipositional behavior inE. amerinae. The results show clearly that females ofE. amerinae can recognize and choose their host willow,S. pentandra, on the basis of phenolic glucosides. Moreover, they are probably able to use phenolic glucosides as a cue in shoot selection within host-plant individuals.
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    Induction of parasitoid attracting synomone in brussels sprouts plants by feeding ofPieris brassicae larvae: Role of mechanical damage and herbivore elicitor (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 2229-2247 
    Details
    ISSN: 1573-1561
    Keywords: Lepidoptera ; Pieridae ; Hymenoptera ; Braconidae ; cabbage ; Brussels sprouts ; behavior ; tritrophic interactions ; green-leaf volatiles ; herbivore-induced synomones ; elicitor ; caterpillar regurgitant ; Brassica oleracea ; Pieris brassicae ; Cotesia glomerata ; parasitoid ; wasp
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Induction of plant defense in response to herbivory includes the emission of synomones that attract the natural enemies of herbivores. We investigated whether mechanical damage to Brussels sprouts leaves (Brassica oleracea var.gemmifera) is sufficient to obtain attraction of the parasitoidCotesia glomerata or whether feeding byPieris brassicae caterpillars elicits the release of synomones not produced by mechanically damaged leaves. The response of the parasitoidCotesia glomerata to different types of simulated herbivory was observed. Flight-chamber dual-choice tests showed that mechanically damaged cabbage leaves were less attractive than herbivore-damaged leaves and mechanically damaged leaves treated with larval regurgitant. Chemical analysis of the headspace of undamaged, artificially damaged, caterpillar-infested, and caterpillar regurgitant-treated leaves showed that the plant responds to damage with an increased release of volatiles. Greenleaf volatiles and several terpenoids are the major components of cabbage leaf headspace. Terpenoids are emitted in analogous amounts in all treatments, including undamaged leaves. On the other hand, if the plant is infested by caterpillars or if caterpillar regurgitant is applied to damaged leaves, the emission of green-leaf volatiles is highly enhanced. Our data are in contrast with the induction of more specific synomones in other plant species, such as Lima bean and corn.
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    The effect of temperature and pressure on the protonation ofo-phosphate ions at 348.15 and 398.15 K, and at 1.52 and 12.50 MPa (1994)
    Springer
    Journal of solution chemistry 23 (1994), S. 449-468 
    Details
    ISSN: 1572-8927
    Keywords: Phosphate ; protonation ; temperature ; pressure ; calorimetry ; equilibrium constants ; enthalpy and entropy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Flow calorimetry has been used to study the interaction of HPO 4 2− and H2PO 4 − with H+ in water at temperatures of 348.15 and 398.15 K and at pressures of 1.52 and 12.50 MPa. The protonations of HPO 4 2− and H2PO 4 − are exothermic and endothermic, respectively, under these experimental conditions. Under the conditions of this study, the effect of pressure on the enthalpy changes for both reactions is small. Equilibrium constant K, enthalpy change ΔH, and entropy change ΔS values are given for the protonation reactions at each temperature. These values are compared with those reported in the literature. Incorporation into the calculation procedure of reactions involving association between protonated phosphate species to form hydrogen-bonded dimers does not result in better fits of the experimental data.
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    Electrical conductivity measurements of aqueous sodium chloride solutions to 600°C and 300 MPa (1994)
    Springer
    Journal of solution chemistry 23 (1994), S. 997-1018 
    Details
    ISSN: 1572-8927
    Keywords: Conductivity ; aqueous ; sodium chloride ; pressure ; ion association ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Electrical conductance measurements of dilute (〈0.1 mol-kg−1) aqueous NaCl solutions were made primarily to quantify the degree of ion association which increases with increasing temperature and decreasing solvent density. These measurements were carried out at temperatures from 100 to 600°C and pressures up to 300 MPa with a modified version of the apparatus used previously in the high temperature study in this laboratory. Particular emphasis was placed on conditions close to the critical temperaturelpressure region of water, i.e., at 5° intervals from 370 to 400°C. The results verify previous findings that the limiting equivalent conductance Ao of NaCl increases linearly with decreasing density from 0.75 to 0.3 g-cm−1 and also with increasing temperature from 100 to 350°C. Above 350°C. Ao is virtually temperature independent. The logarithm of the molal association constant as calculated exclusively from the data≥400°C is represented as a function of temperature (Kelvin) and the logarithm of the density of water (g-cm−3) as follows: $$log K_m = 0.997 - 650.07/T - (10.420 - 2600.5/T)log\rho _w $$ Note that this function also provides a good representation of the log Km values obtained from 350 to 395°C at densities greater than ca. 0.6 g-cm−3. More precise conductance data now available in the literature suggest a systematic error of unknown origin may exist in the data obtained at lower densities in this region. The relevant thermodynamics quantities derived from differentiation of this equation with respect to temperature and pressure are listed in the text.
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    URL: http://dx.doi.org/10.1007/BF00974100
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    Temperature and flow-induced viscosity transitions for CTAB surfactant solutions (1994)
    Springer
    Rheologica acta 33 (1994), S. 431-437 
    Details
    ISSN: 1435-1528
    Keywords: Cetyltrimethylammonium bromide (CTAB) ; temperature ; shear-induced structure ; non-Newtonian viscosity ; micelles ; phase transition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Abstract We report in this work new results concerning the temperature dependence of the non-Newtonian viscosity of semi-diluted aqueous micellar solutions of cetyltrimethylammonium bromide (CTAB) in the presence of potassium bromide (KBr). Two structural transitions are responsible for the unusual flow curves obtained. The first transition induced by the shear flow corresponds to an induced liquid crystalline phase of the nematic type; the second corresponds to the disappearing of this phase with increase of the temperature.
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    URL: http://dx.doi.org/10.1007/BF00366585
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    Air microwave-induced plasma: Detection of NO in the post-discharge using an ArF laser (1993)
    Springer
    Plasma chemistry and plasma processing 13 (1993), S. 351-364 
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    ISSN: 1572-8986
    Keywords: Air microwave plasma ; laser-induced fluorescence ; temperature ; nitrogen monoxide density
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Technology
    Notes: Abstract ArF laser-induced fluorescence (LIF) spectroscopy was applied to the investigation of the density of NO achieved in the post-discharge of an N2-O2 microwave-induced plasma (2450 MHz). The fluorescence spectrum provides a determination of NO vibrational temperature downstream the discharge. Absolute concentration profiles were determined in the low-temperature region of the post-discharge.
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    URL: http://dx.doi.org/10.1007/BF01466049
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    Relative importance of infochemicals from first and second trophic level in long-range host location by the larval parasitoidCotesia glomerata (1993)
    Springer
    Journal of chemical ecology 19 (1993), S. 47-59 
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    ISSN: 1573-1561
    Keywords: Hymenoptera ; Braconidae ; Lepidoptera ; Pieridae ; Cruciferae ; tritrophic interactions ; foraging behavior ; host-habitat location ; herbivoreinduced synomones ; flight chamber ; infochemicals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Recently parasitoids were hypothesized to encounter a reliability-detectability problem relating to chemical stimuli from the first and second trophic level, when searching for hosts. The relative role of infochemicals originating from the host,Pieris brassicae (second trophic level), and its food plant, cabbage (first trophic level), have been investigated with respect to long-range host location by the larval parasitoidCotesia glomerata. Flight-chamber dual choice tests showed that uninfested cabbage plants are least attractive to female wasps. Host larvae and their feces were more attractive than clean plants but far less attractive than artificially damaged and herbivore-damaged plants. The plant-host complex, with host larvae actively feeding on the plant, was the most attractive odor source for the parasitoids. The data indicate that one of the solutionsC. glomerata uses to solve the reliability-detectability problem is to respond to infochemicals that are emitted from herbivore-damaged plants. Whether these infochemicals are herbivore-induced synomones that are produced by the plant remains to be demonstrated. Infochemicals emitted by the herbivore or its by-products are of little importance in the foraging behavior ofC. glomerata.
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    URL: http://dx.doi.org/10.1007/BF00987470
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    Survival of pine sawflies in cocoon stage in relation to resin acid content of larval food (1993)
    Springer
    Journal of chemical ecology 19 (1993), S. 2881-2890 
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    ISSN: 1573-1561
    Keywords: Three-trophic-level interaction ; Pinus sylvestris ; diterpenoid resin acids ; Neodiprion sertifer ; Hymenoptera ; Diprionidae ; predators ; Sorex araneus ; carabid beetle ; Coleoptera ; Carabidae ; parasitoids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Several experiments were conducted to determine whether the ingestion of diterpenoids (resin acids) by pine sawfly larvae influences the survival of postlarval stages. Larvae of two diprionid sawfly species were reared on shoots of two Scots pine clones, one with a low (1.5% dry wt) concentration of resin acids and the other with a high (5.2% dry wt) concentration. No significant treatment-related differences were found in any of the experiments with respect to (1) resistance against parasitoids, (2) preference of predatory shrews and carabids, and (3) apparency of cocoons in the field to predators. A preference of sawfly prepupae to spin cocoon in feces from larvae reared on high resin acid needles was found. Possible explanations for these results are discussed. Detection of an unknown compound, possibly a breakdown product of the major resin acid in pine needles (pinifolic acid), in prepupae indicate that resin acids may be metabolized by the sawflies.
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    URL: http://dx.doi.org/10.1007/BF00980589
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    Host recognition and the study of a chemical basis for attraction by cuckoo bumble bees (Hymenoptera: Apidae) (1993)
    Springer
    Journal of chemical ecology 19 (1993), S. 771-786 
    Details
    ISSN: 1573-1561
    Keywords: Host recognition ; volatiles ; social parasitism ; cuckoo bumble bees ; Bombus terrestris ; Bombus terricola ; Psithyrus vestalis ; Psithyrus ashtoni ; Hymenoptera ; Apidae ; Dufour's gland ; tergal gland
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Species ofPsithyrus (Hymenoptera; Apidae) are obligate bumble bee social parasites. In this study, females ofP. vestalis andP. ashtoni were presented with pentane extracts prepared from different body parts of queens of their respective host species,Bombus terrestris andB. terricola. Parasites of both species were capable of distinguishing host bees from other bumble bee species using chemical cues contained within extracts. Among extracts of several body parts presented to parasites, the abdomen produced the greatest behavioral response, with Dufour's gland and terminal tergal segments eliciting the greatest response among abdominal regions. Extracts of these two body parts obtained fromB. terrestris queens shared a number of compounds, identified by GC-MS. Among the identified compounds are a number that have been reported to be of importance in bee sociochemistry.
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    Iridoid glycosides ofChelone glabra (Scrophulariaceae) and their sequestration by larvae of a sawfly,Tenthredo grandis (Tenthredinidae) (1993)
    Springer
    Journal of chemical ecology 19 (1993), S. 815-823 
    Details
    ISSN: 1573-1561
    Keywords: Chelone glabra ; iridoid glycoside ; plant-insect interactions ; sawfly ; sequest+ration ; Tenthredo grandis ; Hymenoptera ; Tenthredinidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Analysis ofChelone glabra (Scrophulariaceae) by gas chromatography showed that leaves of this plant contained primarily the iridoid glycoside catalpol, and in a few individuals some aucubin was also detected. There was no difference in the iridoid glycoside content of damaged compared to undamaged plants, nor was there a difference between plants collected from a population in Leverett, Massachusetts, and those from plants in an experimental garden in Cambridge, Massachusetts. Larvae and prepupae of the sawfly,Tenthredo grandis (Tenthredinidae) contained catalpol sequestered from the larval host plant. The exuvia also contained catalpol, whereas the frass contained only aucubin. These results indicate that larvae of this sawfly selectively sequester catalpol, eliminating the aucubin in the frass.
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    Variation with caste of the mandibular gland secretion in the leaf-cutting antAtta sexdens rubropilosa (1993)
    Springer
    Journal of chemical ecology 19 (1993), S. 907-918 
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    ISSN: 1573-1561
    Keywords: 4-Methyl-3-heptanone ; 4-methyl-3-heptanol ; citral ; neral ; geranial ; Hymenoptera ; Formicidae ; caste ; Atta sexdens rubropilosa
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract InAtta sexdens rubropilosa, a strongly polyethic and polymorphic species of myrmicine ant, the contents of the mandibular gland vary with caste. Small workers of head width 0.5–1.8 mm, those generally engaged in duties inside the nest, contain chiefly 4-methyl-3-heptanone. Larger workers, those chiefly engaged in foraging, and the soldier caste contain a mixture dominated by neral and geranial, with very little of the ketone of the smaller workers. The soldiers have massive glands containing milligram amounts of neral and geranial. Virgin and mated females contain essentially only 4-methyl-3-heptanone, the amount increasing after mating, while virgin males have 4-methyl-3-heptanone and 4-methyl-3-heptanol in approximately equal proportions. Mated males have less secretion and lose the 4-methyl-3-heptanol.
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    URL: http://dx.doi.org/10.1007/BF00992527
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    Source of sex pheromone of the egg-larval parasitoid,Ascogaster reticulatus Watanabe (Hymenoptera: Braconidae) (1993)
    Springer
    Journal of chemical ecology 19 (1993), S. 963-969 
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    ISSN: 1573-1561
    Keywords: Sex pheromone gland ; mating behavior ; Ascogaster reticulatus ; Hymenoptera ; Braconidae ; egg-larval parasitoid ; Adoxophyes sp. ; Lepidoptera ; Tortricidae ; tibia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A sex pheromone ofAscogaster reticulatus Watanabe (Hymenoptera: Braconidae), identified as (Z)-9-hexadecenal, elicits males' antennal matesearching behavior. In order to localize the source of sex pheromone production, each body part was separated and extracted with hexane and then subjected to 9-cm Petri dish bioassay. The highest activity was found in thorax extract. Among legs, wings, and thorax, legs have the highest activity. Among fore, middle, and hind legs, hind legs have the highest activity. Among coxa and trochanter, femur, tibia, and tarsus, tibia has the highest activity. From these results, the presence of a tibial sex pheromone gland was suggested.
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    URL: http://dx.doi.org/10.1007/BF00992531
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    Nonfloral sources of chemicals that attract male euglossine bees (Apidae: Euglossini) (1993)
    Springer
    Journal of chemical ecology 19 (1993), S. 3017-3027 
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    ISSN: 1573-1561
    Keywords: Hymenoptera ; Apidae ; Euglossini ; floral fragrance ; fungi ; skatole ; chemical ecology ; orchid ; rotting wood
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract We present chemical analysis of four rotten or fungus-infected logs that attracted fragrance-collecting male euglossine bees. Eight of the 10 volatile compounds detected have never been found in the fragrances of orchids pollinated by male euglossine bees. Nonfloral sources of chemicals such as rotting wood may constitute an important fragrance resource for male bees. Since rotten logs produce large quantities of chemicals over long periods of time, such nonfloral sources might be more important than flowers as a source of certain fragrances for some euglossine bee species. Fragrance collecting in euglossine bees might have evolved originally in relation with rotting wood rather than flowers.
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    URL: http://dx.doi.org/10.1007/BF00980599
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    The dufour gland and the secretion placed on eggs of two species of social wasps,Liostenogaster flavolineata andParischnogaster jacobsoni (vespidae: Stenogastrinae) (1993)
    Springer
    Journal of chemical ecology 19 (1993), S. 279-290 
    Details
    ISSN: 1573-1561
    Keywords: Hymenoptera ; Vespidae ; Stenogastrinae ; Dufour gland ; Larval food ; egg secretion ; ant guard ; emulsifier ; eicosyloxyethanol ; hydrocarbons
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The secretion placed on eggs and fed to larvae and the “ant guard” placed on the nest stalk ofParischnogaster jacobsoni contain the same hydrocarbons and in approximately the same proportions as is found in the Dufour gland. The secretion on eggs is a mixture of the contents of the Dufour gland and nectar. The emulsifying agent is a palmitic acid salt. Similarly, inLiostenogaster flavolineata, the egg secretion is an emulsion of nectar and Dufour gland secretion, which contains alkoxyethanol emulsifiers, found in nature for the first time.
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    Dufour's gland and poison gland chemistry of the myrmicine ant,Messor capensis (Mayr) (1993)
    Springer
    Journal of chemical ecology 19 (1993), S. 1315-1321 
    Details
    ISSN: 1573-1561
    Keywords: Dufour's gland ; poison gland ; myrmicine ant ; alkanes ; alkenes ; anabaseine ; anabasine ; alkaloids ; Hymenoptera ; Formicidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The Cape harvester ant,Messor capensis (Mayr), is widespread in the more arid regions of southern Africa, where it forms trails many meters long and harvests considerable quantities of seeds. The poison gland contains primarily the alkaloid, anabaseine, with minor amounts of the related alkaloid, anabasine, and an unidentified compound. The Dufour's gland contains predominantly alkanes and alkenes of carbon chain length 12–23.n-Pentadecane is the major component, with lesser amounts ofn-pentadecene,n-tridecane,n-heptadecane,n-tetradecane,n-heneicosene, andn-tricosene. The dienes,n-heneicosadiene andn-tricosadiene are rather unusual components of the Dufour's gland of ants.
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    URL: http://dx.doi.org/10.1007/BF00984878
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    Identification and synthesis of a kairomone inducing oviposition by parasitoidAphytis melinus from California red scale covers (1993)
    Springer
    Journal of chemical ecology 19 (1993), S. 1721-1736 
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    ISSN: 1573-1561
    Keywords: Kairomone ; oviposition stimulant ; O-caffeoyltyrosine ; Aphytis melinus ; Hymenoptera ; Encyrtidae ; Aonidiella aurantii ; Homoptera ; Diaspididae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The parasitoid waspAphytis melinus uses a kairomone from the cover of its scale host, California red scale (Aonidiella aurantii), as an oviposition stimulant. The kairomone was isolated from extracts of scale covers, and identified asO-caffeoyltyrosine by a combination of spectroscopic methods. The kairomone was synthesized, and the synthetic compound was determined to be as active as the chemical isolated from scale covers.
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    URL: http://dx.doi.org/10.1007/BF00982303
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    Secondary amines isolated from venom gland of dolichoderine antTechnomyrmex albipes (1993)
    Springer
    Journal of chemical ecology 19 (1993), S. 2183-2192 
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    ISSN: 1573-1561
    Keywords: Hymenoptera ; Formicidae ; ant ; Technomyrmex albipes ; unsaturated secondary amines ; venom gland ; GC-MS
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A series of unsaturated secondary amines have been isolated from the dolichoderine antTechnomyrmex albipes (F. Smith). The major components of the mixture have been shown by spectroscopic procedures to be dinon-8-enylamine, andN-hept-6-enylnon-8-enamine, and these structural assignments have been confirmed by synthesis. Mass spectrometry indicates the presence of trace amounts of the bis C11 amine and the C9-C11 amine. The four amines, present in total at approximately 2.8μg/ant, are located in the gaster of the insect in a gland that is considered to be the venom gland although it is atypical from a morphological standpoint.
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    URL: http://dx.doi.org/10.1007/BF00979656
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    Recognition of aphid parasitoids by honeydew-collecting ants: The role of cuticular lipids in a chemical mimicry system (1993)
    Springer
    Journal of chemical ecology 19 (1993), S. 2143-2153 
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    ISSN: 1573-1561
    Keywords: Aphis fabae cirsiiacanthoidis ; Homoptera ; Aphidae ; ants ; antparasitoid interactions ; Hymenoptera ; Formicidae ; Aphidiidae ; parasitoids ; Lysiphlebus cardui ; Trioxys angelicae ; cuticular lipids ; chemical mimicry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The aphidiid waspLysiphlebus cardui parasitizes in ant-attendedAphis fabae cirsiiacanthoidis colonies without causing aggressive behavior in the antLasius niger. By contrast,Trioxys angelicae, another aphidiid parasitoid of aphids, is rapidly recognized and vigorously attacked by the ants.L. niger workers also responded differently to dead individuals ofL. cardui andT. angelicae. DeadL. cardui parasitoids were often ignored when encountered byL. niger, whereas deadT. angelicae individuals were immediately grasped by ants that discovered them. However, hexane-washed parasitoids caused a similar reaction pattern in the ants, in that both aphidiid species were tolerated in the aphid colony. Lure experiments demonstrated that chemical stimuli on the cuticle are major cues for the ants to distinguish between the parasitoids. The hexane extract ofL. cardui transferred to washed individuals ofT. angelicae resulted in ant responses characteristic towardsL. cardui, andL. niger workers displayed the typical removal pattern they normally showed towardsT. angelicae whenT. angelicae extract was applied toL. cardui individuals. Both parasitoid species treated with the hexane extract ofA. fabae cirsiiacanthoidis were similarily treated by the ants as were aphid control individuals. The suggestion that the aphidiid waspL. cardui uses chemical mimicry is discussed.
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    URL: http://dx.doi.org/10.1007/BF00979653
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