bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationship between the in vivo and in vitro activity of some naturally occurring glutamate analogues on the somatic neuromuscular junction of Lucilia sericata
Authors: HART R. J. , POTTER C. , WRIGHT R. A. , LEA P. J.
Published: March 2008

ABSTRACT. A preparation of Lucilia sericata flight motor system was arranged so that ganglionic and neuromuscular function could be monitored while experimental compounds were injected into the intact insect. Injections of l‐glutamate, the putative excitatory transmitter at the insect neuromuscular junction, caused a reversible paralysis of the flight muscles. A number of structural analogues of l‐glutamic acid, found in various seed plants, were injected and the results compared. The salts of several of these compounds were as active or more active in causing the paralysis than glutamate itself. Two of the most toxic compounds, salts of 4‐methylene glutamic acid and quisqualic acid were further tested in vitro by iontophoretically applying them directly to exposed insect neuromuscular junctions. Both compounds showed glutamate‐agonistic activity when applied directly to the neuromuscular junction but were less active than glutamate. This difference between in vivo and in vitro effects is caused by removal mechanisms which protect the muscle membranes from the effects of glutamate. These mechanisms do not so readily remove or inactivate 4‐methylene glutamate or quisqualate. Consequently, for a given dose, the concentration of the analogues at the neuromuscular junction remains longer above the critical level which causes paralysis.
Vision in Drosophila: evidence for the involvement of retinula cells 1–6 in the orientation behaviour of Drosophila melanogaster
Authors: MORTON PETER D. , COSENS DEREK
Published: March 2008

ABSTRACT. Orientation responses of wildtype red‐eye, and mutant brown‐ and white‐eye Drosophila melanogaster were studied in a circular arena. Freely walking flies (‘closed‐loop’) were introduced into the arena and their orientations to a vertical black stripe of angular width 10> were recorded under different chromatic regimes. As has been reported previously, the accuracy of orientation and tropotactic responses were directly related to the extent of eye pigmentation. Orange‐adaptation was found to have little effect on the accuracy of orientation, but blue‐adaptation affected this orientation in all three phenotypes, with statistically significant diminutions in their responses. An electro‐physiological study confirmed the inferred effect of blue‐adaptation, namely that it causes a decreased sensitivity in retinula cells 1–6 by converting the visual pigment R480 to a stable metarhodopsin M580. It is concluded that these retinula cells are involved in orientation behaviour requiring a high degree of visual acuity in Drosophila.
Mechanisms of freezing tolerance in an Antarctic midge, Belgica antarctica
Authors: BAUST JOHN G. , EDWARDS JOHN S.
Published: March 2008

ABSTRACT. The larvae and adults of Belgica antarctica were studied in an attempt to identify the mechanism of low temperature adaptation that enables this species to survive in the Antarctic. Larvae are freezing‐tolerant during the austral summer and elaborate a complex of cryoprotectants including erythritol, glucose, sucrose and trehalose. Adults are freezing‐susceptible and lack adequate quantities of cryoprotectants. Maintenance on artificial diets indicated that cryoprotectant profiles have food‐source and temperature‐dependent components. In addition, direct utilization of dietary cryoprotectants is suggested.
The control of the anterior extreme position of the hindleg of a walking insect, Carausius morosus
Authors: CRUSE H.
Published: March 2008

ABSTRACT. It is shown that the anterior extreme position of the hindleg of a walking insect is not fixed relative to the body but is determined by the position of the ipsilateral middleleg. This mechanism presumably helps the animal to find support for the hindleg when climbing on branches.
Adipokinetic and hyperglycaemic factor(s) in the corpora cardiaca/corpora allata complex of the stick insect, Carausius morosus.
Authors: GÄDE GERD
Published: March 2008

ABSTRACT. The neurosecretory corpora cardiaca/corpora allata complex of Carausius morosus, a wingless insect of the superorder Orthopteroidea, contains adipokinetic and hyperglycaemic factor(s) capable of elevating lipids in locusts, and carbohydrates in cockroaches. Neither activity can be demonstrated in the stick insect itself, however. In addition, in locusts the Carausius gland extract is able to elevate levels of cyclic AMP in the fat body.
Studies on l‐glutamate in insect haemolymph.
Authors: IRVING S. N. , OSBORNE M. P. , G.WILSON R.
Published: March 2008

ABSTRACT. The neuromuscular junctions of abdominal body wall muscles of larval Lucilia sericata are mainly superficial, with no glial sheath, and are surrounded by a well‐developed subsynaptic reticulum. Injection of l‐glutamate into the haemolymph of adult male Locusta migratoria and larvae of Lucilia sericata caused reversible effects on motor activity. These effects were quantified and dose—response curves are presented. The effective concentration of the injected doses is low enough to be physiologically relevant. Injection of l‐aspartate into Locusta haemolymph affected motor activity. Injection of l‐aspartate into Lucilia larvae produced no detectable effect. Injections combining l‐aspartate and l‐glutamate into Lucilia larvae had a synergistic effect on the duration of paralysis, compared with the same concentration of l‐glutamate injected alone.
Host‐feeding and its effects on the physiology and behaviour of the ichneumonid parasitoid, Coccygomimus turionellae
Authors: SANDLAN K. P.
Published: March 2008

ABSTRACT. Coccygomimus turionellae was found to possess a pre‐ovipositional period of 3–6 days during which it ignored hosts. This period corresponded to the time needed for mature eggs to develop. Once oviposition began, the females exhibited host‐feeding behaviour, using the nutrients for oogenesis. Host‐deprived females were able to mobilize some body tissue in the production of eggs, but this resulted first in the loss of their flight ability and then in an increasing paralysis of their hind legs. Host‐feeding varied from the females only sipping at the wound up to the female ramming her ovipositor around in the wound and/or chewing at the drill site. Wasps that only fed at the wound usually deposited eggs and those that had a high rate of host contact used the hosts mainly for oviposition. Wasps that had been without hosts showed a much greater tendency to feed, often destroying the hosts. The greatest preference for feeding was on hosts that were also highly preferred for oviposition. However, when less desirable beetle pupae were accepted, they were fed on to a larger degree than were the more ovipositionally desirable moth pupae. Host deprived parasitoids demonstrated an increased tendency to feed on hosts that are never naturally used for oviposition.
Stimulatory effect of organic solvents on initiating development in diapausing pupae of the flesh fly, Sarcophaga crassipalpis, and the tobacco hornworm, Manduca sexta
Authors: DENLINGER D. L. , CAMPBELL J. J. , BRADFIELD J. Y.
Published: March 2008

ABSTRACT. Alkanes, diethyl ether, and various other organic solvents proved to be potent stimulants of development in diapausing pupae of Sarcophaga crassipalpis Macquart and of Manduca sexta (Johansson). Topical application of 2μl or vapour exposure for 1–2h was sufficient stimulation for the flies, but the solvent had to be injected to elicit the response in the hornworms. In flies, oxygen consumption increased nearly 100‐fold within 15 min of hexane application, and thereafter persisted at non‐diapause levels. Sensitivity of fly pupae to hexane remained high throughout diapause but acetone sensitivity dropped sharply after the second day in diapause. Acetone applied the day before the onset of diapause averted diapause in flies, and topical application to hornworm larvae 3 days before pupation likewise prevented pupal diapause. Debrained pupae failed to respond to solvent treatment, and we conclude that it is the brain, rather than the prothoracic gland, that responds directly to stimulation.
Auditory nerve and interneurone responses to natural sounds in several species of cicadas
Authors: HUBER FRANZ , WOHLERS DAVID W. , MOORE THOMAS E.
Published: March 2008

ABSTRACT. The calling and courtship songs of 17‐year cicadas and of Say's cicadas differ both in the sound frequency spectrum and in temporal pattern. Multiunit recordings with hook electrodes from the whole auditory nerve show that the hearing organs are especially sensitive to transient stimuli occurring in natural sounds. Artificially produced clicks elicit bursts of spikes synchronized among various primary sensory fibres. These fibres respond to natural calling and courtship songs with a specificity dependent on carrier frequency, rhythm and transient content of the sound, following sound pulses (i.e. tymbal actions) up to repetition rates of 200 Hz. An ascending, plurisegmental interneurone was characterized by intracellular recording and simultaneously stained with cobalt. Its main arborization spatially overlaps the anterior part of the sensory auditory neuropile, and the axon was traced as far as the prothoracic ganglion. Direct input from primary auditory fibres was suggested by latency measurements. Intracellular recordings from such neurons in different species show distinct auditory input, with phasic‐tonic spike responses to tones. In general, the interneurone response is more species‐specific to calling than to courtship songs, and the preferential response to the conspecific calling song is based primarily upon sound frequency content.
Proboscis extension and retraction in the blowfly, Calliphora vicina
Authors: STARRE H. VAN DER , RUIGROK T.
Published: March 2008

ABSTRACT. In measurements of the air pressure in the cephalic air‐sacs of the blowfly, Calliphora vicina R.‐D., negative correlations between air pressure and proboscis extension and retraction were observed, confirming that both extension and retraction are direct muscular actions, extension not being caused by a pneumatic mechanism.
GABA and taurine derivatives on the adhesive spiral of the orb web of Argiope spiders, and their possible behavioural significance
Authors: ANDERSON C. M. , TILLINGHAST E. K.
Published: March 2008

ABSTRACT. Two strongly acidic, ninhydrin‐negative compounds were found in the water soluble fraction of the orb webs of Argiope trifasciata (Lucas) and Argiope aurantia (Forskål). One of these is a derivative of taurine. Aninhydrin‐positive GABA derivative, gabamide, also exists in the water‐soluble fraction of the web.
The imaginal ecdysis of the desert locust, Schistocerca gregaria.
Authors: HUGHES T. D.
Published: March 2008

ABSTRACT. The success of the imaginal ecdysis of the desert locust, Schistocerca gregaria, depends on the inflation of the gut with air. The greater part of gut inflation occurs during Stage 3 of the ecdysis (emergence); by the end of this stage the gut is fully inflated. Deflation occurs during Stage 6, after the completion of expansion. The air‐swallowing motor programme is described. During the first part of Stage 3, the frequency of swallowing is regulated according to the degree of foregut distension. In addition, swallowing within the bouts of emergence behaviour is timed by the metathoracic ganglion. During the second part of Stage 3 these control mechanisms are overriden. The contributions of the inflated gut to emergence and expansion are described.
The hormonal control of migratory flight behaviour in the convergent ladybird beetle, Hippodamia convergens
Authors: RANKIN SUSAN M. , RANKIN MARY ANN
Published: March 2008

ABSTRACT. Topical application of the juvenile hormone mimic, Altosid, to Hippodamia convergens (Guérin‐Méneville) (Coccinellidae) stimulated a significant increase in long‐term flight behaviour in both males and females. Altosid treatment also stimulated ovarian development in females. Topical application of precocene II to H.convergens inhibited flight activity in treated animals of both sexes for about 10 days. Altosid treatment to precocene‐treated beetles significantly increased their migratory behaviour over that of precocene‐treated or acetone‐treated controls. These results indicate that juvenile hormone stimulates migratory flight behaviour in this species along with reproductive development. It is likely that the hormone serves to coordinate migration with reproduction in the young adult.
Some effects of constant temperature and photoperiod on the diapause response of the flesh fly, Sarcophaga argyrostoma
Authors: SAUNDERS D. S.
Published: March 2008

ABSTRACT. The sensitive period for the induction of pupal diapause in Sarcophaga argyrostoma (R.‐D.) (Diptera, Sarcophagidae) extends from the intra‐uterine embryos to puparium formation, although the degree of ‘sensitivity’ declines during that period. Embryos and larvae ‘add up’ both long and short nights to a threshold. The incidence of diapause may also be influenced by the photoperiodic manipulation of female flies containing ovarian eggs. High temperatures eliminate or override the diapause response, whilst lower temperatures enhance it. Still lower temperatures (10–12°C) bring about a high larval and pupal mortality and a failure to pupate which is more marked in long than in short nights. The results are discussed in terms of the external coincidence model and the concept of the ‘photoperiodic counter’.
Specificity of contact sex pheromones in tsetse flies, Glossina spp.
Authors: HUYTON P. M. , LANGLEY P. A. , CARLSON D. A. , SCHWARZ M.
Published: March 2008

ABSTRACT. Interspecific mating tests among seven tsetse species covering the ‘morsitans’ and ‘palpalis’ groups showed a degree of reaction that extends beyond the traditional taxonomic groupings. Tests with either live or dead females as targets produced essentially similar results which shows that differing responses of males are largely the consequence of differences in composition of the female surface cuticular paraffins and not of female behaviour. Gas chromatographic (GLC) analysis of cuticular paraffins tends to confirm this view. Responses of males of different species to dead conspecific males baited with the most active synthetic G.morsitans pheromone were variable. Comparison of behavioural responses and of GLC profiles of cuticular paraffins suggest that the species tested do not share a pheromone structure in common with G.morsitans. Mating tests with G.morsitans males using dead conspecific males baited with a variety of synthetic compounds provided evidence of the molecular configuration required to elicit a mating response. Synthetic 15,19‐dimethyltritriacontane induced a suboptimal response in male G.morsitans but is a likely candidate for a sex pheromone in G.austeni. Although not conclusive, a comparison of behavioural evidence and GLC data has permitted speculation on the nature of sex pheromones in tsetse of the ‘palpalis’ group.
Hormonal regulation of pupation in the codling moth, Laspeyresia pomonella
Authors: SIEBER ROBERT , BENZ GEORG
Published: March 2008

ABSTRACT. According to the different reactions to the juvenoid Altosid®, the last larval instar (L5) of Laspeyresia pomonella (L.) (Tortricidae) reared under ‘long day’ conditions (constant light) was subdivided into three sensitive phases: an additional larval instar, a larval–pupal intermediate, or a pupa. Under short day conditions, the prothoracotropic effect of juvenile hormone (JH) in L5, which have a continuous high titre of JH during the whole instar, indicated that it is not a particular titre of JH but a rise in the titre that can induce the production of moulting hormone. Neck‐ligation experiments showed that JH acts not directly on the prothoracic glands but via the head, probably via the neurosecretory system. The meaning of the JH‐peak in mature L5 reared under long days was determined either by injections with the anti‐JH, precocene II, in combination with applications of Altosid, or by forcing precocene‐treated larvae to a precocious moult by injecting them with ecdysterone. Precocene delayed, and JH accelerated pupation if administered 4.5 days after the L5 ‐moult. JH was also found to stimulate the growth and differentiation of the imaginal discs. Moulting hormone in long‐days reared insects was detected one day after the larvae had spun their cocoon, with a maximum on the second day after spinning. The hormone was also present in freshly moulted pupae. Neck‐ligation of mature larvae indicated that the delay between activation of the prothoracic glands and the production of an effective amount of moulting hormone is less than one day.
The penetration of ionic lanthanum into the central nervous system of the tick, Amblyomma variegatum
Authors: HART R. J. , BEADLE D. J. , BOTHAM R. P.
Published: March 2008

ABSTRACT. The ultrastructure of the tick central nervous system resembles that of insects except that the perineurial layer of specialized glial cells is less well developed in the tick. In particular, the cells are not connected by tight or septate junctions. Probably as a consequence, ionic lanthanum penetrates the entire central nervous system of the tick, whereas it fails to penetrate the perineurium of insects. These observations suggest that ticks lack the ‘blood—brain barrier’ which protects the insect nervous system.
A specialized region of the gastric caeca in the locust, Schistocerca gregaria
Authors: BERNAYS E. A.
Published: March 2008

ABSTRACT. Parts of the posterior caeca of Schistocerca gregaria Forskål are complexly pocketed and the whole caecal lining including the pockets secretes a peritrophic membrane. Such pockets are not present in six other species of Acrididae examined. Preliminary experimental evidence, based on absorption of ingested dyes, suggests that the presence of pockets is related to rapid water absorption and perhaps to sequestering plant toxins ingested in a very polyphagous diet.
Night‐time sun‐compass behaviour of honey bees at the equator
Authors: EDRICH WOLFGANG
Published: March 2008

ABSTRACT. In accordance with the peculiarities of the sun's azimuthal path near the equator, African honey bees observed in their night‐time dances apparently allowed for the azimuth moving backwards at night relative to its day‐time movement. In several cases the bees evidently inferred the actual azimuthal position of the sun, rather than the one that would result from extrapolating a uniform movement of the sun.
A positive correlation between oocyte production and ecdysteroid levels in adult Aedes
Authors: MASLER E. PETER , FUCHS MORTON S. , SAGE BECKY , O'CONNOR JOHN D.
Published: March 2008

ABSTRACT. The ecdysteroid titre of adult females resulting from a cross of Aedes epactius females, an anautogenous mosquito, with Aedes atropalpus males (an autogenous strain) was determined using a radioimmunoassay. The F1 hybrid is autogenous and produces mature oocytes without the benefit of a blood‐meal. The ecdysteroid profile of this hybrid revealed a smaller early peak and a second larger one. Qualitatively the overall hormonal profile appeared quite similar to the ones previously obtained using A.atropalpus females and blood‐fed A.aegypti. Quantitatively, the amount of endogenous hormone exhibited, and the total number of mature oocytes produced, may be positively correlated.
Regional specialization for an optomotor response in the honeybee compound eye
Authors: MOORE DARRELL , PENIKAS JEFF , RANKIN MARY ANN
Published: March 2008

ABSTRACT. The optomotor head‐turning response of the honeybee (Apis mellifera) to a horizontally moving stripe pattern was analysed after occlusion of specific regions of the compound eye. The dorsal half of the eye and the medial region appear to be irrelevant to this behavioural reflex. Occlusion of the ventrolateral portion of the eye, however, even with the remainder of the eye unoccluded, rendered the optomotor system blind. The optomotor response was found to be mediated by an area roughly equal to one‐fifth of the total eye surface with some redundancy in the system, since occlusion of at least half of the zone did not significantly impair the response. These results support the hypothesis of physically separate visual subsystems in the bee eye which are adapted for different functions.
Study of single sensillum responses to pheromone in the light‐brown apple moth, Epiphyas postvittana, using an averaging technique
Authors: CSIRO E. R. RUMBO
Published: March 2008

ABSTRACT. A technique is described for averaging the electrophysiological responses of single olfactory sensilla when repeatedly stimulated with the same odour. This enables measurements of electrophysiological responses to be interpreted in a way not normally possible because of the highly variable nature of the individual responses of sensory cells. When the antennal receptors of males of Epiphyas postvittana are stimulated with a single pheromone component, it is shown that the responses contain sufficient information to detect readily both the onset and removal of a stimulus and also a doubling or halving in the concentration of the pheromone. Significant changes in the spontaneous activity of cells following stimulation are also described.
An oscillation underlying feeding and a number of other behaviours in fifth‐instar Locusta migratoria nymphs
Authors: SIMPSON S. J.
Published: March 2008

ABSTRACT. Behavioural evidence is presented for the presence of an oscillation underlying feeding and a number of other activities in fifth‐instar Locusta migratoria nymphs raised and observed under LD 12:12 with constant access to food. With the oscillation represented for convenience as a sine wave, these behaviours occurred significantly more often in the peak half of the cycle than in the trough half. The period of the oscillation differed between insects, the range being from 12.0 to 16.5 min, but was constant for each insect. Feeding did not occur on every cycle but when it did occur it usually began near the peak of an oscillation. Off‐peak feeding was generally associated with defecation. Other more frequently exhibited behaviours, such as the initiation of locomotion and a variety on non‐locomotory behaviours, occurred on peaks when there was no feeding. Once feeding or locomotion had commenced and during the short period of settling afterwards, rhythmicity in the non‐locomotory behaviour was lost. The nature of the oscillator is not known, other than it is apparently endogenous and is not reset during a 12‐h light phase. The presence of such an intermediate length oscillator may have important implications in the organization of complex behaviour
Food conversion efficiency by fleshfly larvae, Sarcophaga bullata
Authors: FRAENKEL GOTTFRIED
Published: March 2008

ABSTRACT. The efficiency of the conversion of the digested food (ECD) (liver) during the growing period of the larva of Sarcophaga bullata was determined. The values for ECD in four different determinations were 67.8, 69.1, 64.1 and 63.4%. These values are of the same order as ECD determined for some phytophagous caterpillars under the best conditions of food utilization, and seem to represent the highest values obtainable in a multicellular organism. It is concluded that such high efficiency rates have as prerequisites: fast growth in the larvae; and in the food, easy availability, ingestibility, and digestibility, high nutritional value, and reasonably high water content. Bacterial decomposition of the food during the test period appeared scarcely to influence the apparent ECD.
Responses of male Mediterranean fruit flies, Ceratitis capitata, to trimediure in a wind tunnel of novel design
Authors: JONES O. T. , LOMER R. A. , HOWSE P. E.
Published: March 2008

ABSTRACT. The responses of male Ceratitis capitata (Wiedemann) (Diptera; Tephritidae) to trimediure were investigated in a wind tunnel of novel design with disposable plastic walls. Trimediure was presented to the flies either in the form of a discrete ‘plume’ or uniformly dispersed in the air passing through the tunnel. The flies showed an increase in flight activity in response to the two forms of stimulation and performed a zig‐zag anemotactic flight in response to the plume, reminiscent of the behaviour of moths responding to a sex pheromone. They performed a straight, upwind, anemotactic response to the uniformly dispersed odour. The design of wind tunnel used in these tests was found to have several advantages: air flow and turbulence can be easily varied and the plastic walls can be changed to eliminate contamination problems.
Responses to features of the calling song by ascending auditory interneurones in the cricket Gryllus campestris
Authors: STOUT JOHN F. , HUBER FRANZ
Published: March 2008

ABSTRACT. In female Gryllus campestris L., three functional types of ascending auditory intemeurones have been studied by recording from them extracellularly in the split cervical connectives using suction electrodes. Type 1 neurones are characterized by an optimal sensitivity to the carrier frequency of the species calling song (4–5 kHz). They copy the syllable and pause structure of the call at all intensities. The patterned spike discharge is observable at least 8 dB above absolute threshold. With suprathreshold stimulation, the neurones exhibit maximal responses (number of spikes/chirp) around the carrier frequency. The intensity response curves are approximately linear in the range of 40–90 dB SPL. The envelope of each syllable is reflected by a corresponding change in the firing rate, and syllable periods of 24ms and longer are resolved. This type can be considered as a neural correlate for phonotactic behaviour of the female where the syllable period has been found to be the most important temporal parameter. Type 2 neurones are most sensitive in the range of 4–6 and 11–13 kHz. They copy the syllable and pause structure of the species calling song at low and moderate intensities. However, the spikes invade the intersyllable pauses, when stimulated with the calling song at higher intensities (above 85 dB). This is particularly apparent at the onset of a chirp series. The slope of the intensity—response curve mimics that of type 1 units. The neurones cannot follow syllable periods shorter than 32 ms. Type 3 neurones differ from types 1 and 2 by a rather broad‐band sensitivity in the range of 3–16 kHz, and in copying the chirp as a whole. Even at low stimulus intensities, the intersyllable pauses are filled with spikes, and information about the syllable—pause structure is lost. Stimulation with suprathreshold intensities gives rise to a rather uniform, broad‐band response without distinctive peaks. The intensity—response curve is characterized by a higher absolute threshold, and by the reduction in the response magnitude starting above 70–80 dB. These units are not suitable for copying the calling song temporal structure in detail, but would indicate the chirping rhythm. Their strong response in the range of the species courtship song carrier frequency make them suitable to copy the courtship song.
Mating behaviour and the mechanism of male orientation in the anobiid bread beetle, Stegobium paniceum
Authors: WARD J. P.
Published: March 2008

ABSTRACT. An analysis of over 200 encounters between male and female Stegobium paniceum (L.) permitted identification of the main units of behaviour. Experiments showed that the orientation of the male with respect to the female consists of two components: pre‐mounting and post‐mounting. It is suggested that the female actively participates in directing the pre‐mounting component. In the post‐mounting component, however, the male appears to rely primarily on tactile cues which may be associated with the female dorsal setae.
Behaviour of the bark beetle, Ips grandicollis, during host selection
Authors: WITANACHCHI JAYANTHI P. , MORGAN F. D.
Published: March 2008

ABSTRACT. Equal numbers of dispersing Ips grandicollis adults were caught on sticky traps held on susceptible and resistant Pinus radiata trees. When beetles were attracted to the same set of trees using baits of ipsenol (aggregation pheromone), some of the beetles that landed on the boles of the trees bored into the bark. The subsequent response of the tree determined whether the tree was accepted or rejected. In resistant trees, the exudation of resin prevented continued boring and led to the retreat of the beetles. In susceptible trees, continued boring led to the establishment of the beetles. Ipsenol was not detected in males that retreated after boring into resistant trees. Beetles that bored into P. radiata logs obtained from slash, continued to bore into the bark, due to the absence of any of the resistance mechanisms; ipsenol was detected in such males. Extracts of groups of male beetles caught from the dispersing population on pheromone‐baited traps, contained little or no ipsenol.
Chilled Galleria mellonella larvae: mechanism of supernumerary moulting
Authors: BOGUŚ MIECZYSŁAWA I. , CYMBOROWSKI BRONISŁAW
Published: March 2008

ABSTRACT. Supernumerary larval instars were produced when Galleria mellonella L. (Lepidoptera) larvae were chilled at 0°C. Although sensitivity to cooling stress of the last instar and younger larvae were generally the same, only penultimate and the last instar larvae showed a significant correlation between their age and the number of additional larval moults. Chilling stress induced a rapid and persistent increase in the JH titre of the last instar larvae. Severing the ventral nerve cord resulted in a predictable loss of the ability to produce supernumerary moults in chilled last instar larvae. The data suggest that sensory input stimulates allatotropic hormone secretion by the brain of chilled larvae. The possible mechanism controlling supernumerary moulting is discussed.
Developmental and behavioural responses of larval Trichoplusia ni to parasitization by an imported braconid parasite Chelonus sp
Authors: JONES DAVY , JONES GRACE , HAMMOCK BRUCE D.
Published: March 2008

ABSTRACT. Larval Trichoplusia ni (Hübner) (Noctuidae) parasitized by Chelonus sp. (near curvimaculatus) (Braconidae) precociously initiated pupation during the penultimate fourth instar. The temporal sequence of developmental markers exhibited by parasitized T. ni closely matched the temporal sequence in normal, pupating larvae. The parasitized larvae did not complete pupation, but consistently stopped development at a stage recognizable by a certain set of markers. This halt was observed in hosts from which parasites emerged and from hosts which had been stung but from which no parasites emerged. Weight gain and food consumption by parasitized hosts were significantly lower than normal, although most reached the fourth instar at the same time as normal larvae. Measurement of head capsule widths indicated that the width in precociously pupating larvae was less than the critical width associated with attainment of the pupation instar of normal larvae.
Modification of sex pheromone blend discrimination in male Oriental fruit moths by pre‐exposure to (E)‐8‐dodecenyl acetate
Authors: LINN C. E. , ROELOFS W. L.
Published: March 2008

ABSTRACT. A pre‐exposure regime was developed to test the hypothesis that arrestment of in‐flight behaviour in Oriental fruit moths, Grapholitha molesta (Busck), to high dosage and/or high %(E)‐8‐dodecenyl acetate blends was due to a high proportion of E8‐12: Ac in the pheromone blend. When tested in a sustained‐flight tunnel to various ratios of (Z)‐ and (E)‐8‐dodecenyl acetate plus a constant % of Z8‐12: OH at two dosages (3 and 100μg), males displayed an optimum number of completed flights to the source to the natural 6%E blend at 3 μg, with significant decreases in response levels occurring to high %E blends at both dosages. Pre‐exposure of males to E8‐12: Ac alone enhanced their response at each dosage to selected higher %E blends that normally elicited low numbers of completed flights. Pre‐exposure enhanced all aspects of the flight response, but this was dependent on both dosage and duration of pre‐exposure, with later behaviours in the sequence (landing and hairpencil display) requiring greater amounts of pre‐exposure than early behaviour (taking flight). Pre‐exposure did not affect high response levels to optimal blends or low response levels to the highest or lowest blends tested at each dosage. The selective nature of the pre‐exposure effect implied alteration of central processes in discrimination of blend rather than disturbance of olfactory receptor function.
Elimination of protein‐food ingested into the crop, and failure of ovarian development in female mosquitoes, Culex pipiens pallens
Authors: UCHIDA KEIKICHI , SUZUKI KATSUHIKO
Published: March 2008

ABSTRACT. A protein‐food rarely activates oogenesis in female mosquitoes when the protein is mixed with sugar and therefore ingested into the crop. A high occurrence of ovarian development occurs, however, when the protein is stored in the midgut. Examination of female C. pipiens pallens fed on egg albumin containing sugar revealed that the protein, once stored in the crop, was easily eliminated without any absorption and that ovarian development occurred only in those few females which retained some part of the ingested albumin for more than 24 h after feeding. Sugar mixed with the albumin was not detected in any excreta of fed females, suggesting that the sugar was digested irrespective of the protein elimination.
Competition between fixed and moving stripes in the control of orientation by flying Drosophila
Authors: DAVID C. T.
Published: March 2008

ABSTRACT. The direction in which Drosophila hydei Sturtevant flew in response to the movement of a striped pattern beneath them was biased along a direction parallel to the long axis of a stationary stripe between them and the pattern. This was not due to the flies reacting to the movement of the ends of the stripes along the long edges of the stationary one, since a stationary stripe above the flies, not between them and the pattern, similarly biased their flight direction. It was due instead to an optomotor turning reaction induced by the edges of the stationary stripe as the flies were led towards or away from it by their turning and speed control reactions to the moving stripes.
Cephalic influences on a defensive behaviour in the dogbane tiger moth, Cycnia tenera
Authors: FULLARD JAMES H.
Published: March 2008

ABSTRACT. The dogbane tiger moth (Cycnia tenera Hübner; Arctiidae) responds to ultrasonic, artificial bat echolocation signals by emitting stereotyped trains of high‐frequency, rapidly repeated clicks. By comparing this response in intact and headless moths, the role of protocerebral auditory inter‐neurones suggested by other studies was examined. Individual moths were tested intact and decapitated, and their response differences analysed. Response latency and threshold (dB) did not alter with the removal of the head but response duration and responsiveness to stimulus trains were significantly reduced in headless moths. These data are interpreted as suggesting the existence of a reflex arc connecting the moth's tympanic organ (ear) with its sound‐producing structure (tymbal), and as providing preliminary evidence that the role of higher‐order interneurones is primarily that of response reinforcement.
Copulatory behaviour of the tsetse flies Glossina morsitans and G.austeni
Authors: HUYTON P. M. , LANGLEY P. A.
Published: March 2008

ABSTRACT. The copulatory behaviour of Glossina morsitans morsitans West. and G.austeni Newst. was analysed by filming. After a male and female engaged genitalia, the male performed a repertoire of five actions for 3–4 min: (1) ‘rubbing’ his metathoracic, tibiotarsal joint against the region of genital contact; (2) ‘stroking’ or hitting the female's head and thorax with his meso‐ and metathoracic legs; (3) ‘wing flick’ by moving his mesothoracic legs in a rowing motion whilst at the same time vibrating the wings as in normal flight; (4) ‘wing vibration’ with the wings vibrated in the closed position; (5) ‘wings out’ in which the wings are moved out to the flying position without any observable vibration. Each action was repeated many times, to give variable individual sequences, but declined in frequency exponentially over the first 3–4 min in copulo. The two species differed in the frequency of acts. Shortly before separation, a few hours later, actions 1 and 2 reappeared. Receptive females exhibited little overt behaviour except in the maintenance of a passive stance. Refractory females rejected a mating attempt by flexing the abdomen ventrally, vibrating their wings in the closed position, and pushing the male with meso‐ and metathoracic legs. The significance and possible functions of male behaviour are discussed in relation to mating in Glossina and other Diptera.
The causes of mating abstention in male tsetse flies Glossina morsitans
Authors: COATES T. W. , LANGLEY P. A.
Published: March 2008

ABSTRACT. The sexual response of a Glossina morsitans morsitans Westw. male towards a decoy consisting of a dead male dosed with synthetic sex pheromone, was depressed by the presence of the cuticular lipids of the decoy male. However, addition of a C24 paraffin, not normally found on or in the cuticle of male or female G.m.morsitans, to a decoy male from which cuticular lipids were removed had a similar effect. Addition of either the C24 paraffin or an extract of male cuticular lipids to decoy females which possess natural sex pheromone in their cuticles, again depressed the sexual responses of males towards the decoys. The n‐hexane solvent used in the application of compounds to decoys, itself depressed responses towards natural pheromone on a dead female at volumes in excess of 100μl, presumably because it mixed the surface waxes which masked the pheromone. Occlusion experiments implied that sex pheromone receptors are present on both the tarsi and tibiae of the male. No evidence was found for the existence of a specific mating deterrent on or in the cuticle of male G.m. morsitans.
Effects of flight training on flight speed and substrate utilization in locusts
Authors: JUTSUM A. R. , ROBINSON N. L. , GOLDSWORTHY G. J.
Published: March 2008

ABSTRACT. Regular flight exercise of adult male Locusta migratoria migratorioides (R and F) accelerated the development of maximum flight speed and disrupted the development of the typical pattern of change of flight speed exhibited when normal (untrained) adult male laboratory locusts are flown on roundabouts. Thus, while untrained mature locusts fly fast initially and then slow to a steady cruising speed after 20 min, trained locusts flew at a relatively constant speed throughout a 60‐min test period. Flight training also led to a marked reduction in the size of the fat body and the flight muscles, but flight muscle ultrastructural development was not affected. Regular flight exercise had no long‐term effect on haemolymph carbohydrate concentration but lipid levels were significantly depressed.
Patterns in feeding: a behavioural analysis using Locusta migratoria nymphs
Authors: SIMPSON S. J.
Published: March 2008

ABSTRACT. Feeding patterns of Locusta migratoria L. nymphs, kept under LD 12:12 at 30°C with ample food, were analysed over the first 6 days of the fifth instar. A number of differences were found between the light and dark phases. (1) More was eaten during the light than the dark, with the differences becoming progressively larger over the 6 days. (2) During light phases most insects showed an increasing tendency to feed with time since the last meal, while in the dark the probability of starting to feed remained constant. (3) There was little variation in feeding patterns within the light phase, but marked changes occurred within the dark phase, feeding declining to a low level in the last 4h. The amount eaten during a meal was regulated similarly in the light and dark, with time rather than amount eaten being of paramount importance in terminating a meal. The time when feeding started was somewhat influenced by the size of the preceding meal, but once feeding began meal size was largely independent of the preceding meal. The importance of food quality in determining the pattern of feeding is discussed.
The effects of pheromone concentration on the flight behaviour of the oriental fruit moth, Grapholitha molesta
Authors: KUENEN L. P. S. , BAKER THOMAS C.
Published: March 2008

ABSTRACT. Male oriental fruit moths, Grapholitha molesta (Busck) (Tortricidae), flew at lower overall and net ground velocities when they flew toward higher concentration pheromone sources. Turning frequency was greater with increased pheromone concentration, while the distance of turns from the plume axis back towards the axis decreased. Turning magnitude and inter‐reversal track angles remained constant at all concentrations tested. Concomitant with the changes in ground velocity but constant inter‐reversal angles, were decreases in airspeed, decreases in the moths' course angles and increases in their drift angles. The significance of these changes is discussed in relation to their possible role in a longitudinal chemoklinotactic programme of turning operating in conjunction with anemotaxis to allow location of a pheromone source in wind.
Direction‐sensitive partitioning of the honeybee optomotor system
Authors: MOORE DARRELL , RANKIN MARY ANN
Published: March 2008

ABSTRACT. The horizontal motion‐detecting system controlling optomotor head‐turning behaviour in honeybees, Apis mellifera, was found to be partitioned into two separate subsystems. Each subsystem is direction‐specific such that visual stimulation in the preferred direction elicited a high level of responses that correcly followed the movement, whereas stimulation in the non‐preferred direction resulted in response levels comparable to or lower than those for blinded controls. The results indicate that medial eye regions are specialized for the detection of posterior‐to‐anterior movements and lateral regions are specialized for detecting anterior‐to‐posterior motion. A model suggesting possible neural correlates for this functional subdivision of the optomotor response is proposed.
Photoperiodic effect on size‐related metamorphosis in the milkweed leaf beetle, Labidomera clivicollis
Authors: PALMER JAMES O.
Published: March 2008

ABSTRACT. Photoperiod significantly affected size‐related aspects of metamorphosis in the milkweed leaf beetle Labidomera clivicollis (Kirby) (Chrysomelidae). Larvae reared under short‐day photoperiod successfully pupated at lower weights than larvae reared under long‐day photoperiods. This short‐day effect was observed to an equivalent extent in both males and females; but within photoperiod treatments, males consistently pupated at lower weights than females. It is likely that the short‐day effect on metamorphosis is associated with photo‐periodically induced changes in larval corpora allata activity or juvenile hormone titre. Ecologically, the short‐day effect on metamorphosis may enhance the moulting success of larvae which encounter food shortages during autumn.
Abnormal vitelline envelope induced by unphysiological doses of ecdysterone in Aedes aegypti
Authors: RAIKHEL ALEXANDER S. , LEA ARDEN O.
Published: March 2008

ABSTRACT. The oocytes of 3‐day‐old unfed Aedes aegypti mosquitoes are in a state of oogenic arrest, but microgram doses of ecdysterone stimulate their accumulation of a variable amount of yolk. We now find that these doses also induce the deposition of plaques of vitelline envelope by the follicle cells, and with transmission electron microscopy we have compared their formation with that in normal blood‐fed females. Plaques in the experimental animals were abnormally large and irregular in shape and distribution. In part, these abnormalities were attributable to the fact that the follicle cells remain in close contact with the oocyte, whereas the space between follicle cells and oocyte increase significantly in the blood‐fed female. Deposition of the plaques occurred earliest after the injection of 5 μg ecdysterone, but even at this high dose the amount of plaque material deposited was less than in the blood‐fed controls. Induction of the deposition of abnormal vitelline envelope in unfed females was most clearly demonstrated after two injections, 1 μg ecdysterone each, 14h apart; 24h after the second injection, the plaques had prematurely fused into a thin disorganized envelope. When females were injected with ecdysterone immediately after a blood‐meal, vitelline envelope plaques formed prematurely, and their structure became increasingly abnormal with time. This early onset of activity was characteristic of follicle cells adjacent both to the oocyte and to nurse cells. Thus, the factors that normally control the formation and organization of the vitelline envelope are absent in the unfed female stimulated with high doses of ecdysterone, while in the blood‐fed females, excessive ecdysterone apparently interferes with the timing and orderly sequence of envelope formation.
Daily rhythms in the sorghum shootfly, Atherigona soccata: oviposition, egg‐hatch and adult eclosion
Authors: RAINA ASHOK K.
Published: March 2008

ABSTRACT. Daily rhythms controlling oviposition, egg‐hatching and adult eclosion in the sorghum shootfly, Atherigona soccata Rondani, were investigated. Eggs were laid only during the photophase of a LD 12:12 cycle, in two peaks. Under continuous light, this oviposition was considerably attenuated but not made immediately arrhythmic. Egg‐hatching and adult eclosion both commenced just before dawn. Some feature of the scotophase during or immediately after black‐head formation apparently acts as a signal for hatching. Eclosion was controlled by light but its timing in the field was modified by temperature. The last 2–3 days of the pupal period constituted the most sensitive stage, and light signals received during this period determined the time of eclosion. Ecological advantages of these rhythms to the shootfly are discussed.
Grasshopper sexual pheromone: a component of the defensive secretion in Taeniopoda eques
Authors: WHITMAN DOUGLAS W.
Published: March 2008

ABSTRACT. Both male and female Taeniopoda eques (Burmeister) emit a defensive secretion from their thoracic spiracles. The secretion from mature females was found to act as a sex pheromone, eliciting mating behaviour in males. Females became chemically attractive to males about 16–18 days after eclosion. The antennae are shown to be the site of pheromone reception in males. Feeding upon natural host plants was not a prerequisite for pheromone production.
Interaction of the neuroendocrine system and ovaries in sheep blowflies, Lucilia sericata, sterilized with tepa
Authors: APPLIN D. G.
Published: March 2008

ABSTRACT. Female Lucilia sericata Mg. fed a reproductive diet of meat were sterilized by injection of 10μg of tepa. Light microscopy revealed that the medial neurosecretory cells of the brain of sterilized flies were highly active compared with the same cells in untreated flies of similar age and nutritional status. The corpora allata of sterilized flies were also greatly enlarged. The evidence suggests that developing oocytes secrete a substance that inhibits the corpora allata hormone, thereby suppressing brain neurosecretory cell activity and preventing oogenesis in the subsequent oocytes.