bluuebunny/crossref_metadata_2025_split huggingface dataset:
Temporal events of gypsy moth vitellogenesis and ovarian development
Authors: LAMISON CRAIG D. , BALLARINO JOANNE , MA MICHAEL 
Published: March 2008

Abstract The vitellogenic period of gypsy moth ovarian development starts on day 3 of the pupal stage and continues through adulthood. During this period, rapid increases occur in follicle size, protein content, and wet weight of the ovary. Patency is observed on day 3 of the pupal stage.Pre‐vitellogenic follicles are formed in the last larval stadium. Newly formed follicles detach from the germarium on day 4, and increase rapidly to 140 per ovariole at the end of the last larval stadium. The pre‐vitellogenic follicles are uniformly around 50 um in diameter. No vitellogenin is incorporated into the oocytes until the pupal stage.Polyacrylamide gel electrophosesis (PAGE) in the presence of sodium dodecylsulphate (SDS) analysis of male and female haemolymph samples and vitellogenic ovaries demonstrates the presence of two female‐specific subunits of vitellogenin of 180 kD and 160 kD. These proteins are detected only in haemolymph and ovarian extracts of vitellogenic females. The molecular weight of the native protein determined by size exclusion chromatography is approximately 400–420 kD.A highly sensitive double antibody sandwich enzyme‐linked immunosorbent assay (ELISA) was developed to monitor the temporal changes in vitellogenin titre in haemolymph. Vitellogenin production starts on day 2 of the last larval stadium, reaching a maximum level by day 6 of the last larval stadium, and decreasing in the late pupal stage as vitellogenin was internalized into the oocytes. This is the first report of vitellogenin production occurring in the larval stage of a holometabolous insect. The fact that vitellogenin production and uptake occur during different stages of development in the gypsy moth, opens up some interesting questions concerning the underlying regulatory mechanisms controlling each process.
Response properties of CO2‐sensitive receptors in tsetse flies (Diptera: Glossina Palpalis)
Authors: BOGNER FRANZ 
Published: March 2008

Abstract. Extracellular single cell recordings of CO2‐sensitive receptors in tsetse flies revealed a steep dose response over a range of stimuli of two to three orders of magnitude and a maximum response of approximately 70 impulses/s after exposure to a high, but naturally feasible, C02 concentration of 5%. These receptor neurones are slightly sensitive to C02 levels occurring in air (‐0.03%); the sensitivity to CO2 above that level may be used to locate potential hosts. The C02‐sensitive neurones did not respond to some other biologically relevant odours such as octenol, butanone or p‐cresol; however, other receptor cells, some in the same sensillum, are sensitive to some of these odours.A striking feature of the C02 receptors is that they appear not to adapt in their response frequencies. The spike numbers of the phasic‐tonic response remain constant in the tonic portion during continuous (or repetitively pulsed) long‐term stimulation (1 min). This unusual physiological ability would allow continuous monitoring of C02 values as well as detecting potential hosts that exhale CO2. These electrophysiological results are compared to the behavioural findings in tsetse flies and to the physiological data on C02 receptors of other, non‐bloodsucking insects.
Geographic variation of diapause intensity in the spider mite Tetranychus urticae
Authors: KOVEOS D. S. , KROON A. , VEERMAN A. 
Published: March 2008

Abstract. Eight strains of the spider mite Tetranychus urticae, originating from different localities in western and central Europe, with latitudes ranging from 40.5 to 60oN, displayed marked differences in the period of chilling at 4oC required for diapause termination under a diapause‐maintaining short‐day photoperiodic regime at 19oC, to which the mites were transferred after the cold period. The higher the latitude from which the strains originated the longer was the period of chilling required for diapause termination, suggesting the presence of a gradient in diapause intensity, diapause being deeper the more northern the origin of the strains.Two strains originating from higher altitudes appeared to have a much deeper diapause than expected from their latitudinal origin. In addition, these two mountain strains showed mutual differences in diapause intensity, notwithstanding the fact that they originated from similar latitudes and altitudes; local climatic conditions probably act as strong selective forces with regard to diapause depth.All strains appeared to be sensitive to photoperiod during the period of diapause development. Diapause was quickly completed by a long‐day photoperiod (LD 17:7 h), but was maintained by a short‐day photoperiod (LD 10:14h). However, even under the latter regime sensitivity to photoperiod gradually diminished and eventually disappeared, thus leading to ‘spontaneous’ termination of diapause. The length of the period of diapause development, as measured by the sensitivity to photoperiod of diapausing mites, varied between strains; it was shorter in the southern strains and longer in the northern strains. The results indicate great variation in diapause intensity between strains, which is probably genetically determined and may have adaptive significance for this widespread species.When young females which had just entered diapause were kept for ever longer periods of time under the diapause inducing short‐day regime at which they had been reared, before being transferred to the cold room, the duration of the period of chilling required for diapause termination was found to decrease proportionally in all three strains tested. These results suggest that intensification of diapause does not occur in T. urticae; diapause intensity seems to be highest at the beginning of diapause and to diminish gradually during diapause development.
Transient uptake of hypericin by chrysomelids is regulated by feeding behaviour
Authors: DUFFEY S. S. , PASTEELS J. M. 
Published: March 2008

Abstract. The uptake of hypericin from the foliage of Hypericum perforatum by four species of adult chrysomelid beetles, Chrysolina brunsvicensis, C. geminata, C. hyperici and C. varians, was investigated under laboratory conditions. In no species were detectable levels of hypericin passed from the larval to the pupal or adult stages. The total amount of hypericin found in the adult beetles was positively related to the rate of ingestion of foliage. When feeding activity lessened or ceased, body levels of hypericin declined. In adults of C. brunsvicensis, C. hyperici and C. varians maximal body levels of hypericin occurred after 1–10 days of feeding. In C. brunsvicensis a maximal average level of c. 0.96 μg/beetle was obtained. After 20 days body levels in C. brunsvicensis declined to nearly zero. Adults of C. brunsvicensis contained more hypericin than the other species of beetles, but in no case was enough hypericin sequestered to match the original values (c. 13.3 μg/beetle) published by Rees (1969). Our results caste doubt on the role of hypericin as a sequestered defence against predators.Analysis of body distribution of hypericin indicated the majority was in the gut lumen (80%). An input‐output analysis of hypericin ingested by adults of C. brunsvicensis showed that the greatest majority of hypericin was eliminated in the faeces (up to 85%). Between 15% and 35% of the ingested hypericin was unaccounted for. This loss is the result of a post‐defecational degradation of hypericin (perhaps bacterial).
The migration syndrome in the African armyworm moth, Spodoptera exempts: allocation of resources to flight and reproduction
Authors: GUNN A. , GATEHOUSE A. G. 
Published: March 2008

Abstract. Selection for the capacity for prolonged tethered flight in Spodoptera exempta resulted in heavier moths, with significantly larger abdominal glyceride glycerol contents in females of two flight‐selected strains (87% and 49% higher than in the comparable non‐selected strain) and in males of one of them (80% higher). All flight‐selected strains contained individuals of both sexes with very high abdominal glyceride levels. There was no significant relationship between abdominal total glyceride glycerol after flight and flight duration for non‐selected moths, but an inverse linear relationship was evident in both sexes from a flight‐selected strain. Oxygen consumption during tethered flights by flight‐selected moths ranged from 28.2 to 56.6 ml O2g‐1h‐1.Using these and previous data, notional energy budgets were calculated to account for flight, reproduction and resting metabolism for non‐selected and flight‐selected S. exempta flown on the flight balances and provided thereafter with distilled water. The results confirm the trade‐off between flight and reproduction reported by Gunn et al. (1989). A similar approach using data for two non‐selected strains from the field in Kenya indicated genetic variation in migratory potential, reflected both in pre‐reproductive period and resources available for flight. We conclude that elevated glyceride levels are a component of the migratory syndrome in S. exempta and that this is the major factor underlying the curvilinear relationship between flight duration and fecundity obtained by Gunn et al. (1989).
Turbulence, trees and semiochemicals: wind‐tunnel orientation of the predator, Rhizophagus grandis, to its barkbeetle prey, Dendroctonus micans
Authors: WYATT TRISTRAM D. , PHILLIPS ALUN D. G. , GRÉGOIRE JEAN‐CLAUDE 
Published: March 2008

Abstract. Insects apparently responding to the visual stimulus offered by a tree or other object may also be responding to the variety of physical effects caused by the obstruction, including turbulence, a reduction in wind velocity and eddies. The relative importance of prey odour associated with the bark beetle Dendroctonus micans (Kugelann) (Scolytidae), prey‐host‐tree odour, silhouette, and physical barrier to the wind, in the orientation and landing behaviour of a predatory beetle, Rhizophagus grandis Gyllenhall (Rhizophagidae), were investigated. R. grandis responded very positively to the frass of its prey when presented on a ‘tree’ but not to the same quantity of frass presented alone. Frass on black plastic uPVC pipes was significantly more attractive than frass on real host tree logs, suggesting that host‐tree volatiles do not enhance the attractiveness of prey frass.The beetles responded to ‘transparent’ Mylar three‐dimensional cylinders in the same way as they did to the black plastic pipes. Beetles were also tested with frass and two‐dimensional stimuli offering a visual stimulus or physical barrier alone or in combination. Frass with a two‐dimensional visual stimulus was no better than frass alone: few insects landed. Significantly more insects were attracted to the same two‐dimensional visual stimulus with a hidden upwind barrier producing turbulence, but a similar number were attracted to the frass in front of a hidden barrier alone. As many plants are similar in size to the logs used in these experiments, comparable effects might influence the behaviour of other phytophagous insects, their predators and parasitoids.
Deterrence coding by a larval Manduca chemosensory neurone mediating rejection of a non‐host plant, Canna generalis L.
Authors: PETERSON STEVEN C. , HANSON FRANK E. , WARTHEN J. DAVID 
Published: March 2008

Abstract. The physiological basis of phagodeterrence was studied electrophy‐siologically and behaviourally in the phytophagous caterpillars Manduca sexta and Manduca quinquemaculata. The model unacceptable non‐host plant was the canna lily, Canna generalis.A strongly deterrent extract was obtained from fresh leaves of canna by extraction with hot ethanol or ethyl acetate in a blender. Behavioural rejection of these extracts was similar to that of fresh leaves, although less intense. In contrast, blender extracts using other solvents, as well as leaf surface rinses, were phagostimulant or neutral. Chromatographic fractionation of the deterrent ethanolic extract showed the active principles to be moderately polar and separable into two fractions.Previous ablation experiments had shown that the medial maxillary styloconica and epipharyngeal sensilla are the two most important chemosensory organs in mediating behavioural rejection of canna leaves; if only one of these organs is spared, the animal completely rejects canna. We investigated the neural responses of the medial styloconica and their contribution to the sensory coding responsible for this phagodeterrence.The active fractions of the deterrent ethanolic extract elicited a vigorous response from one chemosensory neurone in the medial styloconica. This neurone is distinguishable from others in the medial styloconica by its unique temporal response parameters and the characteristic shape changes of its action potentials. The response frequency of this neurone correlates with the degree of phagodeterrence in a dose‐dependent manner. Threshold deterrence occurs at a concentration of extract (1%) that elicits firing in this neurone at a rate of c. 50 spikes/s peak instantaneous frequency and 30 total spikes in the first Is.We conclude that this is a ’deterrent neurone’ in the sense that vigorous response from this neurone is a sufficient sensory code for behavioural rejection of canna. Thus input from a single sensory neurone is capable of blocking feeding, since only one (unilateral) medial styloconicum is needed to mediate this rejection.
An electroantennogram apparatus for testing the activity of semiochemicals on the olive beetle, Phloeotribus scarabaeoides (Coleoptera: Scolytidae): first recordings of the response to ethylene
Authors: GONZÁLEZ RAMON , ÁLVAREZ ALFREDO , CAMPOS MERCEDES 
Published: March 2008

Abstract. An electroantennogram (EAG) apparatus for testing the activity of pheromones of the olive beetle, Phloeotribus scarabaeoides, is described. This inexpensive device is suitable for whole antennal recording from scolytids. The modification of the amplifier and sample injection system, described previously, eliminate parasitic noise and improve the recording of the EAG signal.Results from previous studies revealed significant beetle attraction to a source releasing ethylene. Serial solutions of 2‐chloro‐ethyl phosphonic acid were tested, and 10% acetic acid served as a standard.A significant variation in amplitude of depolarization was found among the different concentrations of 2‐chloro‐ethyl phosphonic acid tested. Maximum depolarization was elicited at a concentration of 0.1% in both males and females. In general, no statistical differences in responses were found between males and females, but females showed a significantly lower threshold of response.
Tarsal contact chemoreceptor for the host marking pheromone of the cherry fruit fly, Rhagoletis cerasi: responses to natural and synthetic compounds
Authors: STÄDLER ERICH , ERNST BEAT , HURTER JAKOB , BOLLER ERNST 
Published: March 2008

Abstract. The European cherry fruit fly (Rhagoletis cerasi L.; Diptera, Tephritidae) marks cherries (Prunus avium L.) after oviposition with a host marking pheromone (HMP). The marking trail prevents additional oviposition by the same or other females into the same fruit. On the ventral side of the tarsi of both sexes, contact‐chemoreceptor sensilla were identified which contain a receptor cell selectively sensitive to HMP. The HMP receptors of males were slightly more sensitive than those of females, suggesting that the more general term ‘host‐marking pheromone’ is more appropriate than the previously used ‘oviposition deterring pheromone (ODP)’.The four structural isomers of the HMP, N(15R, S(β‐glucopyranosyl)‐oxy‐8RS‐hydroxypalmitoyl)‐taurine, and various derivatives were synthesized and tested in an electrophysiological bioassay. Both the 8R,15R and the 8S,15RS isomers of the HMP were equally active with a threshold of about 2 times 10‐10M, and were shown to be present in the female faeces in similar proportions. The two 15S HMP isomers were about 13 times less active.Testing synthetic derivatives of the HMP molecule revealed that the presence of the four moieties of the molecule are important for the activity: taurine, palmitic acid, C(8) hydroxyl group, and glucose (C(15)). The chain length of the fatty acid, the hydroxyl group at C(8) and the position of glucose at C(15) also influenced the activity. Only minor loss of activity (factor 2) relative to the natural molecule was observed when the methyl group in the C(15) position was removed. The removal of the β‐glycosidically linked glucose (replaced by a hydroxyl group) resulted in about a 4‐fold loss of activity. The cation of the HMP molecule seemed to have no effect on its activity, whereas both low and high pH reduced it significantly.Based on these results, field experiments have been initiated to control oviposition by cherry fruit flies on cherries applying the 15‐desmethyl‐HMP derivative.
Physiological correlates to courtship, mating, ovarian development and maternal behaviour in the ring‐legged earwig
Authors: RANKIN SUSAN M. , FOX KELLY M. , STOTSKY CHRISTOPHER E. 
Published: March 2008

Abstract. The involvement of the endocrine system in courtship, mating, maternal behaviour and the gonadotrophic cycle was studied in the earwig, Euborellia annulipes, after application of JH III and, alternatively, precocene II.Topical application of 35 or 122 μg of JH III to newly eclosed females advanced the onset of courtship behaviour from 6.6 ± 1.3 days in acetone‐treated controls to 1.4 ± 2.8 and 0.5 ± 2.5 days, respectively. Application of 6 μg of JH III had no effect on the onset of courtship behaviour. Applications of Juvenile Hormone had no significant effect on the age at first mating nor on the duration of mating, though the trend is towards advanced onset. The age at first oviposition was advanced by hormone treatment; clutch size and the proportion of offspring hatching was reduced by hormone treatment. The interclutch interval, size and proportion hatching of the second clutch were not affected by hormone treatment.Topical application of 50 μg of JH III to females on the day of oviposition shortened the total duration of maternal care from 15.4 ± 0.5 to 5.3 ± 1.7 days; whereas in acetone‐treated and precocene II‐treated groups maternal care lasted 16.1 ± 1.9 and 13.8 ± 1.6 days, respectively. The duration of maternal care was positively correlated with number of offspring hatching and fledging.In a corollary experiment, topical application of JH III significantly enhanced the onset of the second gonadotrophic cycle as assessed by basal follicle length; application of 20 μg of precocene II, either singly or in repeated doses, did not delay growth of basal follicles. Finally, repeated application of as much as 80 μg of precocene II had no effect on basal follicle length, nor on ovary wet weights.These results are consistent with the hypothesis that intermediate to high titres of JH are associated with oocyte growth, mating, and the cessation of maternal care; low titres of JH appear to be associated with the period of maternal behaviour and slow ovarian follicle development.
Behavioural plasticity in the stinging act of female ectoparasitoids
Authors: ROJAS‐ROUSSE DANIELLE , DOURY GERALDINE , TERRASSE CHRISTOPHE , KALMES ROBERT 
Published: March 2008

Abstract. The plasticity of the stinging behaviour of female Eupelmidae (Eupelmus vuilleti Crawford, E. orientalis Crawford Hymenoptera: Eupelmidae) was analysed through the interrelationships of a parasitic community living on larval stage of Callosobruchus maculatus Fabricius (Coleoptera: Bruchidae). In traditional African grainstores, Eupelmus females have at their disposal all the larval stages of their host. Their exploitation is revealed by the sting observed on the host caused by the ovipositor of parasitoid females. This stinging behaviour begins immediately on the adult female's emergence, and thereafter there is a daily increase in the number of hosts stung. Stinging activity is linked to the age of the available hosts, but not all of the hosts available are exploited by the two species studied. This absence of total exploitation could indicate a threshold of activity in the stinging acts which could be in part linked to the secretion activity of the poison glands of parasitoid female.In females of E. vuilleti and E.orientalis the stinging act is usually associated with egg‐laying. The relationship between stinging and egg‐laying is stronger in more advanced larval stages of the host.In the presence of parasitized hosts, females of E. orientalis and E.vuilleti can exhibit hyperparasitism. The majority of larvae (i.e. primary parasitoid) that have been hyperparasitized have been stung and a large number of them are completely inactive. However, E. vuilleti females deposited their eggs in the available space of the pupation chamber of the host. The neonatal larvae from these scattered eggs could exploit any available host without the female having ‘prepared the ground’ at the time of egg‐laying.In Eupelmidae, all this happens as if there were a complementary action between the females and the neonate which could, if necessary, reinforce and/or compensate for the deficiencies in the host exploitation by the female.
Effects of food quality on growth and body composition of the collembolan Orchesella cincta
Authors: LAVY D. , VERHOEF H.A. 
Published: March 2008

Abstract.The effects of food quality on growth and body composition of the collembolanOrchesella cincta(L.) (Entomobryidae) were investigated to determine optimal values for dietary nitrogen.Hyphae ofCladosporium cladosporioidescontaining 2.2%, 2.7%, 4.0% and 6.2% nitrogen were used as food sources.These different nitrogen contents were obtained by adjusting the medium on which the fungi were grown.Collembola were fed on one of these four food sources for 8 weeks.O.cincta grew faster and reached a higher asymptotic body mass when fed on fungi with 4% or 6.2% nitrogen content: this effect decreased with higher nitrogen content.The lipid concentration in the animals was negatively correlated with dietary nitrogen content, whereas protein concentration was positively correlated.Glycogen concentration was not found to correlate with the composition of the food.A mechanism is proposed by whichO.cincta compensates for low dietary nitrogen by consuming more to maintain a relatively constant amount of protein in its body and, as a result, accumulates more fat than animals fed on fungi with a higher nitrogen content.
Resource partitioning and tolerance of monoterpenes in four species of spruce aphid
Authors: JACKSON DEBORAH L. , JAROSIK VOYTECH , DIXON ANTHONY F.G. 
Published: March 2008

Abstract. The tolerance of four species of aphids to myrcene was assessed by measuring the mortality of aphids exposed to different amounts of this monoterpene.Each species was found to exhibit significantly different levels of tolerance to myrcene.which is explicable in terms of the likely concentration of myrcene at the feeding site of each species.Tolerance to monoterpenes maybe specific only to those encountered in high concentrations at the feeding site.whereas others are found to be toxic.This suggests that each species has become physiologically adapted to tolerate different levels of the specific monoterpenes that occur in the microhabitats they occupy.