bluuebunny/crossref_metadata_2025 huggingface dataset:
Visual deprivation and distance estimation in the praying mantis larva
Authors: WALCHER F. , KRAL K.
Published: March 2008

Abstract. Young larvae of the praying mantis, Tenodera sinensis Saussure, were placed on an off‐centre island surrounded by a round arena with six black bars painted on a white inner wall. In this situation, it was shown that the horizontal peering movements of the head often seen in mantids are in fact used to measure distances; motion parallax may be involved in this process. Aimed jumps that followed peering were taken to be the distinct result of an absolute distance measurement. Specific visual deprivation such as painting over of certain parts of the eye with opaque black varnish or degeneration of the fovea with sulforhodamine showed that: absolute evaluation of distance is only possible with two fully intact eyes; the peering mechanism is under visual control; and visual experience has a long‐term effect on distance measurement involving peering movements.
Thin‐layer chromatographic isolation of the trall pheromone of the ant Pheidole pallidula
Authors: CAMMAERTS MARIE‐CLAIRE , CAMMAERTS ROGER
Published: March 2008

Abstract. Although the presence of small amounts of 3‐ethyl‐2,5‐dimethylpyrazine (EDMP) has been reported in the poison gland of the Pheidole pallidula minor workers, this substance is not the true trail pheromone of this ant. This pyrazine acts as an attractant and a locostimulant. Appropriate solvent extractions and thin‐layer chromatography of poison glands, together with trail bioassays, have shown that another substance acts as the trail pheromone. Furthermore, there seems to be an auxiliary pheromone, acting as a synergist; this might be EDMP.
Perception of volatiles associated with sex and food by different adult forms of the black bean aphid, Aphis fabae
Authors: HARDIE JIM , VISSER J. H. , PIRON P. G. M.
Published: March 2008

Abstract. Electroantennograms (EAGs) were recorded from adult male and asexual forms (winged and wingless virginoparae and gynoparae) of the black bean aphid, Aphis fabae, during stimulation with two sex pheromone components, (+)‐(4aS,7S,7aR)‐nepetalactone and (‐)‐(1R,4aS,7S,7aR)‐nepetalactol, as well as six plant volatiles, i.e. (E)‐2‐hexenal, (E)‐2‐hexenol‐1, (Z)‐3‐hexenol‐1, (Z)‐3‐hexenyl acetate, hexanal and allyl isothiocyanate. The male antennae are 1000‐10,000 times more sensitive to nepetalactol and nepetalactone than to the plant compound (E)‐2‐hexenal. Besides this marked difference of EAG peak responses in males, the EAG rise and decay are slower for the sex pheromone components. Males are also much more sensitive to the sex pheromone components than asexual females. This high sensitivity correlates with a predominance of antennal secondary rhinaria, the major sites of pheromone perception in the male. However, it is the primary rhinaria on the antennae of the wingless asexual females that are responsible for pheromone perception. Male antennae are as responsive as the asexual female antennae to the plant volatiles. The specialization of the male for mate location is discussed.
Laboratory and field response of the pollen beetle, Meligethes aeneus, to the odour of oilseed rape
Authors: EVANS K. A. , ALLEN‐WILLIAMS L. J.
Published: March 2008

Abstract. The behavioural response of adults of the pollen beetle, Meligethes aeneus F. (Coleoptera: Nitidulidae), to the odour of one of their host‐plants, oilseed rape (Brassica napus L.), was observed in the laboratory using a fourarmed airflow olfactometer, and under semi‐natural conditions using a markrelease–recapture technique. Oilseed rape leaf and flower odour was attractive to pollen beetles in the olfactometer and they dispersed upwind from the centre of a circular array (radius 20 m) of yellow water traps, baited with extracts of oilseed rape leaves or flowers. The dispersal of pollen beetles in the absence of oilseed rape odour was predominantly downwind and crosswind. The percentage recapture of pollen beetles was significantly greater in traps baited with rape flower extracts than leaf extracts. Pollen beetles can use odour‐mediated upwind anemotaxis to locate oilseed rape plants from distances of at least 20 m over open ground.
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.
Reproductive rates of tsetse flies in the field in Zimbabwe
Authors: HARGROVE J. W.
Published: March 2008

Abstract. Tsetse flies Glossina morsitans morsitans Westwood and G. pallidipes Austen were marked and released within 12 h of emergence at Rekomitjie Research Station, Zambezi Valley, Zimbabwe, and on Redcliff Island, Lake Kariba. Ovarian dissections were performed on recaptured flies and on wild collected samples. At Rekomitjie >90% of female G. m. morsitans were inseminated by age 4 days and G. pallidipes by 7 days. For both species at both sites the length of the largest oocyte, for flies in ovarian category zero, increased approximately linearly for about the first 6 days and was ovulated at c. 6–8 days. The largest oocyte grew significantly more slowly in later cycles. For G. m. morsitans, but not for G. pallidipes, the rate increased with temperature; the rates were always higher than observed in the laboratory. At Rekomitjie, for both species and at a mean screen temperature of 22d̀C, the first larva was produced at c. 18 days and subsequent larvae at 11–day intervals; the intervals decreased with temperature by c. 0.5 days/d̀C. On Redcliff Island the intervals for both species were 2 days shorter than at Rekomitjie at any given screen temperature and were sometimes as short as 7 days. The length of the larva in utero increased exponentially during pregnancy.
Obstacle perception by insect antennae during terrestrial locomotion
Authors: PELLETIER YVAN , McLEOD COLIN D.
Published: March 2008

Abstract. Insect antennae bear several types of sensilla including chemo‐receptors, hygroreceptors, thermoreceptors and mechanoreceptors. A large proportion of sensilla is chemoreceptors, providing olfactory function. Pro‐prioreceptors located on the antennae provide information on the position of these organs and are used in flight control. This type of sensillum is present in most insects and might serve other functions. We tested the hypothesis that antennae are used to perceive obstacles in the path of walking beetles. When adult Colorado potato beetles, Leptinotarsa decemlineata (Say), touch an obstacle with their antennae during terrestrial locomotion, they modify the angle of their body to allow the tarsi of one prothoracic leg to reach the top of the obstacle. Our results demonstrate that antennae, by their movements and their position ahead of the beetle, provide information on the presence of the obstacle necessary to initiate step‐up behaviour. Furthermore, the change in the body angle needed to increase the reach of the prothoracic leg and step on the obstacle, is proportional to the height of the obstacle. Since the eyes are not involved in the process, normal behaviour can be performed in the dark.
Sperm competition and sperm precedence in the dragonfly Nanophya pygmaea
Authors: SIVA‐JOTHY MICHAEL T. , TSUBAKI YOSHITAKA
Published: March 2008

Abstract. The libellulid dragonfly, Nanophya pygmaea Rambur, has an average ejaculate volume of 0.16 mm3. During successive copulations the volume of sperm stored in the female's sperm storage organs increases in steps equivalent to this volume, suggesting that the sperm competition mechanism in this species is sperm repositioning, i.e. adding an ejaculate to what is already present in the female's sperm storage organ. By using sterile/normal males in double matings with females we have shown that this mechanism results in last male sperm precedence (P2= 0.979).
Water relationships in the ectoparasitoid Nasonia vitripennis during larval diapause
Authors: YODER JAY A. , RIVERS DAVID B. , DENLINGER DAVID L.
Published: March 2008

Abstract. Final instar larvae of the ectoparasitoid Nasonia vitripennis overwinter in diapause within the puparium of the host fly. Wasp larvae that are in diapause have a different set of water relations than larvae that are not in diapause. Diapausing larvae contain less water, lose water at a lower rate, and have the capacity to absorb water vapour. Water conservation in larvae of N. vitripennis is also enhanced considerably by the puparium of its fly host.
Behavioural circadian rhythms measured in real‐time by automatic image analysis: applications in parasitoid insects
Authors: ALLEMAND ROLAND , POMPANON FRANCOIS , FLEURY FREDERIC , FOUILLET PIERRE , BOULETREAU MICHEL
Published: March 2008

Abstract. A video analysis system was developed to study behavioural circadian rhythms in insects. Technical innovations were performed in image analysis and in the use of robotics. In image analysis, both the automatic detection of the insect and the calculation of several variables (linear and angular speed, locomotor activity, etc.) are carried out in real‐time, which saves time and allows long‐term studies without any intervention of the operator. The displacement of the camera by robotics allows the simultaneous study of many individuals (i.e. sixty individuals for the study of locomotor activity of adult insects, more than 400 individuals for the study of the emergence of adult parasitoids from their host). Four applications of this new device are presented. They deal with circadian rhythms in parasitoid insects: locomotor activity and time variation in locomotory parameters, daily distribution of the emergence and onset of the locomotor activity in adults. The adaptability of the system to several experimental materials and situations is discussed and the interest of the study of behavioural rhythms in the approach of host‐parasitoid associations is emphasized.
Strategies for recontacting a lost pheromone plume: casting and upwind flight in the male gypsy moth
Authors: KUENEN L. P. S. , CARDÉ RING T.
Published: March 2008

Abstract. Gypsy moth (Lymantria dispar L., Lepidoptera: Lymantriidae) males flying upwind to high concentration pheromone sources had lower ground speeds, shorter crosswind reversal distances and higher turn rates than males flying upwind to low pheromone doses. Casting flight, crosswind flight with no net upwind movement after loss of pheromone contact, developed gradually and was similar in fashion for males initially flying to the three pheromone doses tested; after plume loss, males' flight in the upwind direction decreased from 6 cm turn‐1 to nearly 0 cm turn‐1 by their fifth turn (crosswind reversal). After plume loss, upwind displacement decreased, crosswind distances and inter‐turn duration increased. Ground speeds tended to increase after plume loss, but airspeeds decreased following loss of 10 and 100 ng plumes and remained constant after loss of 1 ng plumes. Latency to casting was c. 1 s as measured by cessation of upwind progress and by timing the first reversal leg that was down or crosswind after plume loss. Though these measures of casting were independent of pheromone concentration, they are means that mask the fact that about 40% of males, rather than cast crosswind after loss of the plume, continued to move upwind, with wider and temporally less regular crosswind reversals. Such continued movement upwind is in sharp contrast to previous descriptions of casting flight after loss of odour‐plume contact. In addition, some males engaged in ‘regressive’ casting, moving downwind after bouts of ‘typical’ casting. The value of casting and of the continued upwind flight after plume loss, both possible strategies for recontacting a pheromone plume, are discussed.
Functional anatomy of the egg pore in Callosobruchus maculatus: a trade‐off between gas‐exchange and protective functions?
Authors: DANIEL SARAH H. , SMITH R. H.
Published: March 2008

Abstract. The chorion of the egg in Callosobruchus maculatus (Coleoptera: Bruchidae) provides protection but also has to allow exchange of respiratory gases. A single opening in the chorion (the egg pore) allows diffusion of gases, and young larvae die if the egg pore is blocked. Comparison of respiration rates using a Gilson respirometer showed an increase in oxygen uptake from the first to the seventh day after the egg was laid; the increase was from 6.8 to 11.2 pl/egg/day in a Brazil strain and from 8.6 to 23.5 pl/egg/day in a Yemen strain. The Yemen strain had double the metabolic rate of Brazil‐strain insects in the larvae, which are exposed to seed toxins, but not in the non‐feeding adults. It is suggested that the higher metabolic rate in the Yemen larvae is related to their ability to develop in seeds that are toxic to the Brazil strain. The egg pore also differed in size and shape between the two strains. The egg pore was cylindrical in the Brazil strain, but shorter and funnel‐shaped with an increased external diameter in the Yemen strain. Calculation showed that the different shape and size of the Yemen egg pore would allow a 2–3‐fold increase in gas conductance compared with the Brazil strain, and this increase was consistent with the enhanced oxygen requirement of the Yemen larvae, which was a little over twice that of the Brazil larvae at 7 days. The anatomy of egg pores in Cmaculatus thus seems to represent a trade‐off between two functions, allowing adequate gas exchange while maintaining the protective function of the chorion.
Pollen feeding in the eucalypt nectar fly, Drosophila flavohirta
Authors: NICOLSON SUSAN W.
Published: March 2008

Abstract. Adults of the eucalypt nectar fly, Drosophila flavohirta Malloch (Diptera: Drosophilidae), feed on Eucalyptus pollen. Flies of both sexes gather pollen with the proboscis, forming a large mass of pollen on the anterior surface of the extended proboscis. Pollen gathering alternates with quiescent periods when the moistened pollen load is continually vibrated. No pollen was found in the adult gut, and it is suggested that hydration of the pollen causes release of nutrients which are then imbibed. This ‘external digestion’ is reminiscent of that employed by heliconiine butterflies.
Some effects of low temperature on the photoperiodic clock in Drosophila triauraria
Authors: YOSHIDA TAKAO , KIMURA MASAHITO T.
Published: March 2008

Abstract. Prior studies revealed that the photoperiodic clock in Drosophila triauraria operates during the scotophase and the processes measuring scotophase are composed of two phases: the A phase which lasts 6–7 h from the onset of the scotophase and the B phase which follows the A phase. In this study the photoperiodic clock in this species was analysed by low‐temperature pulses. Low temperature (5d̀C) or a low‐temperature (2d̀C) pulse of 3 or 4 h decreased the induction of diapause when applied during the scotophase, but not when applied within the photophase. The low‐temperature pulse showed two maxima of the effect, 0–4 h and 8–10 h after the onset of the scotophase, approximately corresponding to the A and B phases, respectively. It is considered that low temperature retards the time measurement processes operating during these phases. In the period which was rather insensitive to the diapause‐preventing action of low temperature, i.e. 5‐7h after the onset of the scotophase, substances or stimuli accumulated during the A phase may be converted to information required for operation of the machinery in the B phase. Experiments using a combination of low‐temperature and light pulses suggested that low‐temperature decreases the sensitivity to light, especially in the B phase.
Nutrient regulation in the pea aphid Acyrthosiphon pisum: application of a novel geometric framework to sugar and amino acid consumption
Authors: ABISGOLD J. D. , SIMPSON S. J. , DOUGLAS A. E.
Published: March 2008

Abstract. A recently developed framework was applied to investigate the responses of newborn pea aphids, Acyrthosiphon pisum (Harris) (Homoptera: Aphididae), to simultaneous variations in dietary suerose and amino acid levels. The location of functional ‘targets’ for intake and growth were determined experimentally using performance criteria. Behavioural rules employed by insects to approach these targets were investigated by reference to the geometry of arrays of intake and growth across a range of diets. First‐instar aphids were fed one of thirty‐one chemically‐defined diets ranging in sucrose concentration from 200 to 1000 mM and amino acid concentration from 25 to 250 mM. Insect survivorship, dry weight, protein‐ and carbohydrate‐derived growth were high for all diets except those with the lowest nutrient levels. Peaks in final dry weight and protein content identified the intake target as the point reached by larvae fed the 600 mM sucrose, 75 mM amino acid diet. Aphids regulated sucrose primarily by consumption (i.e. behaviourally), whereas amino acids were regulated post‐ingestively (i.e. by physiological mechanisms).
Endothermic warm‐up in two species of sphecid wasp and its relation to behaviour
Authors: GHAZOUL J. , WILLMER P. G.
Published: March 2008

Abstract. The ability of two sphecid wasps, Bembix rostrata and B.zonata (Hymenoptera: Sphecidae), to warm up endothermically is demonstrated under laboratory conditions. Mean warm‐up rates of B.rostrata are comparable to bees of similar weight. Despite endothermic ability, field observations reveal that B.rostrata are not active below 22d̀C. From observations at the nectar‐foraging site (clumps of Thymus vulgaris flowers) it is calculated that the energy resources available to wasps are sufficient to power endothermic warm‐up at low temperatures. Alternative explanations for the absence of wasp activity at low temperatures, such as the risk of parasitism, are suggested. Endothermy may be used periodically to increase flight efficiency in response to added load, such as prey carried by females, and mates by males.
Behavioural changes are related to moult regulation in the cockroach, Periplaneta americana
Authors: RICHTER KLAUS , BÄRWOLF DANIELA
Published: March 2008

Abstract. Larval holometabolous insects show changes in behaviour (e.g. start of wandering and spinning) in specific periods of the moulting cycle in relation to definite ratios of juvenile hormone and moulting hormone (ecdysone). In hemimetabolous insects no such changes in behaviour are known. It should be investigated whether the cockroach Periplaneta americana shows changes in locomotor activity and in food and water consumption in relation to periods of ecdysone production during the last larval stage. Within a mean duration of the last larval stage of 30 days there were two periods of reduced locomotor activity: on day 9 and between days 13 and 17. From days 12–13 food consumption decreased by c. 40% up to the day 18. Water consumption decreased between days 9 and 18 by about 55%. Peaks of ecdysone production appeared after these changes of behaviour in each case. Therefore in larval Periplaneta ecdysone seems not to trigger these behavioural changes.
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.
Plant‐odour‐specific receptor neurones on the antennae of female and male Spodoptera littoralis
Authors: ANDERSON P. , HANSSON B. S. , LÖFQVIST J.
Published: March 2008

Abstract. Receptor neurones with high selectivity and sensitivity to plant odours were found within short sensilla trichodea on the antenna of both female and male Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae) by using single‐sensillum recording techniques. In 112 sensilla from females and forty‐one from males, twenty‐four different receptor neurone types were characterized according to their specificity. Altogether, twenty‐six plant and three sex pheromone compounds were tested. Receptor neurones responding with high specificity to flower odours, green leaf volatiles, oviposition deterrents and other general host plant odours were identified. In twenty‐one receptor neurone types, responses were elicited by one or several plant compounds, and in three types responses were elicited by sex pheromone compounds. The majority of the receptor neurones responded to only one or two of the tested compounds. In general, only one of the two receptor neurones in a sensillum responded to any of the compounds tested. An exception was a receptor neurone responding to plant odours (green leaf volatiles) and another receptor neurone responding to a sex pheromone compound ([Z]‐7‐dodecenyl (acetate), which occurred in the same sensillum. The majority of the receptor neurones displayed a high sensitivity to plant odours. No morphological difference was identified the different sensillum types.
Towards a general rule for estimating the stage of pregnancy in field‐caught tsetse flies
Authors: HARGROVE J. W.
Published: March 2008

Abstract. Ovarian dissections were performed on the tsetse flies Glossina morsitans morsitans Westwood and G.pallidipes Austen of known ages, maintained in the laboratory or on an island in Lake Kariba, Zimbabwe. The lengths (l2 and lu) of the second largest oocyte and of the larva in utero were found to increase approximately exponentially during pregnancy. The length (l1) of the largest oocyte increased exponentially for about the first 80% of pregnancy. Linear relationships between the log values of l1, l2 and lu in field‐caught flies, of unknown chronological age, are consistent with the idea that growth patterns are similar in laboratory, island and open field situations. The egg phase takes up c. 45% of pregnancy in both species, regardless of season and the absolute duration of pregnancy. The changes in the log values of l1, l2 and lu, over the ranges within which they change linearly, can be used to assign flies to their stage of pregnancy. When applied to field data the rule showed that G.pallidipes caught in odour‐baited traps, and on a mobile electric net, exhibited major activity peaks shortly before and after parturition. Flies from the trap (but not the net) showed a smaller peak of activity near the middle of pregnancy. The egg and the three larval phases in utero take up c. 45%, 25%, 20% and 10% of pregnancy respectively.
Reciprocal regulation of fat content and flight activity in male tsetse flies (Glossina palpalis)
Authors: LOKE HSIN , RANDOLPH SARAH E.
Published: March 2008

Abstract. To disentangle cause and effect in previously observed relationships between fat content and flight activity in male tsetse (Glossina spp.), three groups of flies were fed at different intervals to raise their fat content to different levels before their flight activity was recorded. The greater the mean daily blood intake, the higher the fat content and the greater the subsequent spontaneous flight activity, thereby using up almost all of the fat reserves before the next blood meal. It is proposed that although male flies would benefit from maximum food intake to permit maximum flight associated with mate‐seeking, they do not in fact feed as often as possible either in the field or the laboratory. This is explicable if energy acquisition is constrained by an additional mortality risk associated with feeding.
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.
Interaction of pheromones during food exploitation by the termite Schedorhinotermes lamanianus
Authors: REINHARD JUDITH , KAIB MANFRED
Published: March 2008

Abstract. Chemical signals from secretions of different exocrine glands modulate a variety of behavioural patterns in termite societies. These signals have multiple functions and may be interactive. During food exploitation workers of the African termite Schedorhinotermes lamanianus (Isoptera: Rhinotermitidae) employ, on foraging trails, the secretion from the sternal gland both for orientation and recruitment to a food source. The secretion from the labial gland, released onto the food by gnawing termites, stimulates additional workers to gnaw at the same site, thereby forming aggregations of gnawing termites. An interaction between these two pheromones during food exploitation is demonstrated for the first time. The volatile signal from the sternal gland inhibits in a dose‐dependent manner the non‐volatile, highly persistent, signal from the labial gland. The development of gnawing aggregations is inhibited and established ones are dissolved. Behavioural evidence for the perception of both the volatile signal from the sternal gland by olfactory neurones and of the non‐volatile signal from the labial gland by gustatory neurones on the antennae is given. The interaction of the two pheromones as a basis for the development of distinct commuting and gnawing zones on the food source, and as a means for a dynamic regulation of food exploitation, is discussed.
Innervation of the foregut of the cockroach Leucophaea maderae and inhibition of spontaneous contractile activity by callatostatin neuropeptides
Authors: DUVE HANNE , WREN PAUL , THORPE ALAN
Published: March 2008

Abstract. The innervation of the gut of the cockroach Leucophaea madera (F.) has been studied by means of wholemount immunocytochemistry with antisera raised against Leu‐callatostatin, a cockroach allatostatin homologue identified from neuropeptide isolation and gene studies in the blowfly Calliphora vomitoria. Leu‐callatostatin‐imunoreactive neurones in the brain, with axon trajectories in the stomatogastric nervous system, innervate the foregut and midgut. Neurones in the last abdominal ganglion supply the hindgut and the midgut via the proctodeal nerve. In addition to a rich callatostatin‐immunoreactive nerve supply, the midgut, including the midgut caeca, contain numerous callatostatin‐immunoreactive endocrine cells. Physiological studies show that the spontaneous contractile activities of the foregut, but not the hindgut, are inhibited by callatostatin neuropeptides. Leu‐callatostatin 3 was the most potent of the range of Leu‐and Met‐callatostatins tested, with a dose‐dependent response between 10‐13 and 10‐7 M. This is similar to the results obtained with the previously identified myoinhibitory peptide of L. maderae, leucomyosuppressin. However, this peptide, with a different type of structure to the allatostatins, inhibits both foregut and hindgut motility equally. Experiments with a series of analogues of the Met‐callatostatins showed that the free acid (as opposed to the carboxyamidated peptide) and N‐terminally truncated peptides were inactive. These morphological and physiological results are thought to be representative of the, as yet unidentified, naturally occurring allatostatin homologues of L. maderae. This family of peptides should be added to the increasing list of insect gut myoinhibitory substances.
In vivo and in vitro effects of 20‐hydroxyecdysone and methoprene on diapause maintenance and reproductive development in Musca autumnalis
Authors: KIM YONGGYUN , KRAFSUR E. S.
Published: March 2008

Abstract. Face flies overwinter as adults in reproductive diapause. Administration of 20‐hyroxyecdysone and/or methoprene induced reproductive development in diapausing flies which were maintained in a diapause‐inducing environment. Hormone effects were additive and female flies were more sensitive than males. Release of vitellogenin from cultured fat body was stimulated by 20‐hydroxyecdysone or methoprene. Transfer of flies from diapause to diapause‐breaking environments induced some to break diapause, but this decreased with the time flies had been in a diapause‐inducing environment. In contrast, topical application of methoprene to diapausing flies induced reproductive development irrespective of their ages even when they were kept in the diapause‐inducing environment for 80 day degrees above a 12°C base temperature (14.5 days). Therefore diapause induction must depend on hormone levels less than some threshold level. The putative threshold varied according to diapause propensities of different genetic lines. Lines showing high frequencies of diapause required greater amounts of methoprene for reproductive development in diapause conditions than did lines showing low frequencies of diapause.
Male load‐lifting capacity and mating success in the swarming caddis fly Athripsodes cinereus
Authors: PETERSSON ERIK
Published: March 2008

Abstract. Males of the caddis fly Athripsodes cinereus (Curtis) (Trichoptera: Leptoceridae) swarm above the water surface of lakes and streams. Females enter swarms and are pursued until grasped by a male. The pair couple their genitalia in the air, and then the male alone flies the pair to the shore where they settle and complete the copulation. About 8% of the pairs (total n= 384 pairs) dipped in the water soon after the coupling manoeuvre and about 25% of those then separated. Males in dipping pairs (n= 13) were on average smaller and relatively older than the males that successfully carried their mate to the shore (n= 54). No differences were found for flight muscle ratio (weight of flight muscles/total body weight) or relative load (total load/flight muscle weight). Males were larger than females (wing length), though typically female Trichoptera are the larger sex. Large male body size in A. cinereus may be an adaptation for flight during pairing; i.e. larger males are more likely to be able to carry larger loads.
Behavioural evidence for detection of the repellent polygodial by aphid antennal tip sensilla
Authors: POWELL GLEN , HARDIE JIM , PICKETT JOHN A.
Published: March 2008

Abstract. Close‐up video was used to record responses of the aphid Myzus persicae (Sulzer) (Homoptera: Aphididae) to the plant‐derived repellent polygodial. When 0.1% (±)‐polygodial was painted onto one half of a Chinese cabbage leaf disc, and the other half treated with the ethanol solvent, apterous adult aphids avoided walking onto the polygodial‐treated area during 15 min access periods. Similarly, when the rim of a small plastic Petri dish was treated with polygodial, aphids took significantly longer to walk off the base of the dish and onto the rim, compared with insects in solvent‐treated control dishes. Analysis of video‐recordings indicated that aphids were repelled following contact of antennal tips with the polygodial‐treated areas of leaf or plastic. In contrast, aphids with both antennal tips surgically removed showed no apparent response to polygodial treatment of leaf or plastic surfaces. Aphids were placed between polygodial‐ and solvent‐treated angled glass cover slips to enable unilateral presentation of polygodial on either the left or right side of the insects. Most aphids with antennae intact moved away from the polygodial‐treated side, but removal of both antennal tips again negated the response. When the tip was removed from only one antenna, and the other remained intact, unilateral presentation caused a repellent response only if polygodial occurred on the same side as the intact antenna. Presentation of polygodial on both sides of aphids (bilaterally) caused no response if both antennal tips were intact or removed, but aphids with only one antennal tip removed were repelled from the side where the antenna remained intact. The results indicate that aphids detect polygodial upon contact with sensilla located on the antennal tips, and that the repellent response occurs as a negative chemotropotaxis following unilateral stimulation of these sensilla. Contact between the antennal tips and glass substrates was demonstrated using a fluorescent pigment.
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.
The relationship of age and ovarian development to mating of Delia antiqua (Diptera: Anthomyiidae)
Authors: McDONALD R. S. , BORDEN J. H.
Published: March 2008

Abstract. The relationship between age and sexual receptivity for male and female onion flies, Delia antiqua (Meigen) (Diptera: Anthomyiidae), and factors affecting ovarian development were examined under various conditions. Confinement in small arenas had a significant negative effect on the rate of oogenesis over the first 10 days of adult life and, in some cases, on the percentage of females inseminated. The rate of oogenesis was not affected by male population density, but high density of females in large arenas appeared to have a priming effect. Few males in single‐pair mating bioassays conducted over 24 h were sexually mature at 3–4 days post‐eclosion, but > 50% mated when aged 6–7 days. Although females first mated at 3–4 days post‐eclosion when confined for 24 h with sexually mature males, most females mated at 6–7 days of age when oocytes in the terminal ovariole position comprised 50% of total egg volume (stage 7 or greater on a 10‐stage scale). No females aged 3 days were mated in no‐choice and two‐choice bioassays with sexually mature males over 24 h. Previtellogenic females (stage 3) were not inseminated, and ovarian development was only correlated weakly (r= 0.48) with mating. Frequency of mating in mixed‐sex groups of twenty flies was comparable with that in single pairs. However, more females were inseminated at 3–4 days, probably as a result of multiple matings by a few precocious males. These results do not support the hypothesis that females mate only when ovarioles are mature.
Effects of ovarian development and protein deprivation on the activity and locomotor responses of the blowfly, Lucilia sericata, to liver odour
Authors: ASHWORTH J. R. , WALL R.
Published: March 2008

Abstract. The spontaneous activity and locomotor responses to liver odour of females of the blowfly Lucilia sericata Meigen (Diptera: Calliphoridae) were examined in the laboratory using a rocking‐box olfactometer. Spontaneous activity levels depended on fly age, previous exposure to protein and recent oviposition history; 1‐day‐old females, 3‐day‐old protein‐fed females, and females that had recently oviposited exhibited lower levels of spontaneous activity than protein‐deprived or fully gravid individuals. Changes in locomotor activity in response to liver odour also depended on previous exposure to protein. In protein‐fed flies, activity decreased in response to liver odour and then increased on termination of an odour pulse. This response became more pronounced with age, broadly in line with the expected state of oocyte maturation. This pattern of change was not evident in protein‐deprived females. The results are discussed in relation to the relative importance of protein and oviposition‐site resources to L. sericata and the resultant age and ovarian development‐stage biases evident in field catches.
Effect of temperature on photoperiodic response in a selected ‘non‐diapause’ strain of Pyrrhocoris apterus (Heteroptera)
Authors: HODKOVA M. , SOCHA R.
Published: March 2008

Abstract. The artificially selected ‘non‐diapause’ strain of Pyrrhocoris apterus (L.) (Heteroptera) showed no diapause response to photoperiod at 26°C (Socha & Hodkova, 1994). However, the diapause response to short‐day photoperiod (LD 12:12 h) became apparent at lower temperatures of 17°C (70% diapause) or 20°C (41% diapause). Diapause was induced in 60% females by short‐day photoperiod combined with thermoperiod of 26/16°C, whereas only 20% diapause was induced by the same thermoperiod under continuous darkness. Thus the time‐measuring system was not removed by artificial selection but the diapause response was shifted to lower temperatures. The diapause response to short days seems to be favoured rather by low temperature during scotophase than by low temperature throughout the whole light/dark cycle. If the percentage of diapause at 26°C is compared in F1 hybrids and in wild and selected parental strains the diapause appears to be dominant at LD 13:11 h but recessive at LD 11:13 h and LD 10:14 h. A hypothesis is proposed that the inheritance of the percentage of diapause in F1 hybrids is determined by interactions of genes controlling the temperature dependence of photoperiodic response.
Degradation of cuticle during larval‐pupal and pupal‐adult development of the housefly, Musca domestica
Authors: DWIVEDI JYOTI , AGRAWAL OM P.
Published: March 2008

Abstract. The patterns of changes in cuticle weight, its chitin content and chitinase activity have been studied during postembryonic development of the housefly, Musca domestica L. During pupariation the larval cuticle loses weight. During the early part of this weight‐loss the decline in chitin content parallels the overall change in cuticle weight. A simultaneous elevation in chitinase activity suggests that at this time the larval cuticle is being enzymatically degraded. Later weight loss may be due to sclerotization. No significant changes in cuticle weight or its chitin content occur in pharate cuticle until one day before eclosion. However, a peak of chitinase activity found at mid‐late pupal stage suggests the timing of pupal cuticle breakdown.
Diapause detection and monitoring in the Mediterranean corn stalk borer
Authors: LÓPEZ C. , EIZAGUIRRE M. , ALBAJES R.
Published: March 2008

Abstract. Sesamia nonagrioides Lefebvre diapauses as mature larvae. Once diapause is induced, larvae continue to grow and moult with no apparent changes, so distinction between non‐diapausing and diapausing larvae is difficult. In the present work two physiological markers of diapause induction are obtained and their efficacy in detecting diapause onset and in monitoring diapause development in field populations is evaluated. The first marker is based on the differential capacity of two photoregimes, LD 0:24 h and LD 16:8 h, to reverse diapause induction. When larvae of the first and second stadia were subjected to the diapause‐inducing LD 12:12 h light cycle and then transferred to LD 0:24 h, larvae pupated after a development duration significantly higher than that of the larvae transferred to LD 168 h. This criterion was used to monitor diapause development in overwintering larvae until field‐collected larvae submitted to LD 0:24 h pupated synchronously with those submitted to LD 16:8 h. This occurred between late January and early March. The second marker refers to development of imaginal wing discs. A relative index of the tracheal mass area divided by the total disc area diminishes steadily during development in non‐diapausing sixth‐instar larvae until it becomes zero just before pupation, whereas it remains constant in diapausing larvae. Though wing disc development was blocked in diapausing sixth‐instar larvae, the disc continued to grow and, consequently, the total area of the disc was not a suitable marker of diapause induction. When the constancy of the relative area index was used to monitor diapause development and termination in overwintering larvae, the results agreed with those obtained using the first criterion and with previous field observations.
Novel locomotory mechanisms in caterpillars: life‐line climbing in Epinotia abbreviana (Tortricidae) and Yponomeuta padella (Yponomeutidae)
Authors: BRACKENBURY JOHN
Published: March 2008

Abstract. When alarmed, caterpillars of the tortricid Epinotia abbreviana (Fabricius) and the yponomeutid Yponomeuta padella (Linnaeus) parachute at the end of a single life‐line spun out by the head spinnerets.Two methods are employed to climb back up the line.The first makes use of alternate movements of the left and right set of thoracic legs, aided by side‐to‐side movements of the body.This results in the life‐line being wound in around the third pair of thoracic legs.The second method is based on the normal peristaltic rhythm used when walking on a solid substrate.Dorsoventral curling movements gradually transfer life‐line from the thorax along the succession of abdominal pro‐legs to the claspers at the end of the body.The life‐line has similar physical characteristics to spider orb‐web silk, and a breaking force equivalent to 5–8 times body weight.The holding force of the claspers when in contact with the ground exceeds the breaking force of the life‐line.These studies demonstrate the flexibility of caterpillar locomotion, when confronted with a novel situation.
The role of 1‐octen‐3‐ol as a host‐odour attractant for the biting midge, Culicoides impunctatus Goetghebuer, and interactions of 1‐octen‐3‐ol with a volatile pheromone produced by parous female midges
Authors: BLACKWELL A. , DYER C. , (LUNTZ) A.J.MORDUE , WADHAMS L.J. , MORDUE W.
Published: March 2008

Abstract. 1‐octen‐3‐ol, a component of the body odour of ruminants, is demonstrated to be an attractant for host‐seeking, parous female Culicoides impunctatus Goetghebuer (Diptera, Ceratopogonidae).This compound was electrophysiologically and behaviourally active and, in the field, released at 0.11 ± 0.01 mg/day, increased female C.impunctatus catches over a seven‐day period compared with control catches.When 1‐octen‐3‐ol was combined either with live female midges or an extract of female midges in an electroantennogram assay, additive effects were recorded.Behaviourally, the same combination resulted in both enhanced attraction and repellency, depending on concentration.Attraction was recorded mainly when sub‐threshold concentrations of the separate components were combined.The potential of such a combination as an effective field bait is discussed.