bluuebunny/crossref_metadata_2025 huggingface dataset:
Termination of vitellogenin synthesis by mosquito fat body, a programmed response to ecdysterone
Authors: BOHM M. K. , BEHAN M. , HAGEDORN H. H.
Published: March 2008

ABSTRACT. In the blood‐fed mosquito, peak vitellogenin synthesis occurs 24–32 h after the meal, dropping to resting levels by 40 h. Challenging fat body with ecdysterone in vitro at various times after a blood meal demonstrated a refractory period at about 50 h, when there was also a drastic decrease in mitochondria, rough endoplasmic reticulum, ribosomes, and glycogen in fat body cells. When fat bodies from sugar‐fed females were incubated with continuous ecdysterone in vitro, vitellogenin synthesis reached a peak at 30 h, but then declined even in the presence of ecdysteroné. This was not due to the in vitro conditions since fat bodies were responsive, even if first exposed to ecdysterone, after 80 h in vitro. If ecdysterone was removed, vitellogenin synthesis ceased. If it was replaced, the fat body responded again only if the initial removal was done during the first 30 h. It is proposed that the falling ecdysterone titre is the major cause of cessation of vitellogenin synthesis, but that synthesis is programmed to decline even if exposure to ecdysterone is abnormally prolonged.
The antenna of Drosophila as a ‘love song’ receptor
Authors: EWING ARTHUR W.
Published: March 2008

ABSTRACT. Behavioural experiments have demonstrated that the songs of Drosophila species are involved in courtship and aggression, and suggest that the songs are perceived via Johnston's organ. Direct electrophysiological evidence is here presented to show that the antenna of Drosphila is indeed capable of responding to the range of sounds produced by the flies.
Control of the horizontal flight‐course by air‐current sense organs in Locusta migratoria
Authors: GEWECKE MICHAEL , PHILIPPEN JUERGEN
Published: March 2008

ABSTRACT. The role of the air‐current sense organs of Locusta migratoria (the antennae and the hair fields on the frons and vertex of the head) in control of the horizontal flight‐course in relation to the air was investigated in locusts flying tethered on a torque gauge. The antennae were apparently not of importance in the control of flight direction in the horizontal plane. If the hair fields were stimulated by an air current from either side, however, a torque on the vertical body axis was generated by the beating wings after a reaction time of at least 0.1 s. In free flight this would result in a yaw, bringing the animal back in line with the air stream. This torque reaction will stabilize the flight direction in the horizontal plane via a negative feedback mechanism, the hair fields above the lateral ocelli being the feedback receptors. In free flying locusts a torque on the vertical body axis can be generated by both the beating wings and the abdomen working as a rudder when bent to either side. The wings, however, are dominant in the reflex stabilization of the flight‐course.
The fast phase of optokinetic nystagmus in the locust
Authors: KIEN J. , LAND M. F.
Published: March 2008

ABSTRACT. When their visual environment is rotated about them, freely moving locusts make the typical slow (following) and fast (flick back) phases of optokinetic nystagmus. The fast phase was examined and is compared with that of Crustacea and vertebrates. It is unusual in the locust in that it is symmetrical about the body midline. Mechanoreceptors play a significant role in maintaining the fast phase reset function.
The flicker fusion frequencies of six laboratory insects, and the response of the compound eye to mains fluorescent ‘ripple’
Authors: MIALL R. C.
Published: March 2008

ABSTRACT. The ERG response of the compound eye to single, brief, light pulses, to sustained stimulation for 2 s, and the dark adapted flicker‐fusion frequency (FFF) under stroboscopic light was measured in six species: Locusta migratoria (FFF range: 40–90 Hz), Periplaneta americana (25–60 Hz), Saturnia pavonia (65–85 Hz), Antheraea pernyi (25–70 Hz), Glossina morsitans (85–205 Hz) and Drosophila hydei (60–100 Hz). The first four species have typical ‘slow‐eyed’, monophasic ERG responses; the two flies typical ‘fast‐eyed’, biphasic responses. The FFF proved to be dependent on the state of light adaptation, being 40–70% higher than the above figures after only 2 min exposure to as little as 300 lx. Adult male Glossina, but not Locusta nymphs, showed a clear 100 Hz ERG ripple in response to single‐phase, mains fluorescent lighting. To three‐phase fluorescent lighting no 300 Hz ERG ripple was detected, but the 100 Hz component was still evident.
Patterns of selective protein ingestion by the blowfly Phormia regina
Authors: BELZER W. R.
Published: March 2008

ABSTRACT. The patterns of protein ingestion by Phormia regina were reexamined with an apparatus more sensitive than that used in Dethier's (1961) original study. During the first vitellogenic cycle, females exhibited two peaks of protein consumption if given access to protein from the time of emergence. The first occurred during days 1–2 post‐eclosion; the second during days 3–5, when oocytes were developing. Once the eggs were mature, protein ingestion remained depressed until oviposition; it peaked again for 1–2 days following each oviposition. In the male fly only the first peak of elevated protein ingestion occurred; thereafter, protein ingestion remained low. For both sexes, protein‐deprivation, enforced since eclosion, intensified initial protein meals, which thereafter tailed off rapidly.
The relationship between body angle and flight speed in free‐flying Drosophila
Authors: DAVID C. T.
Published: March 2008

ABSTRACT. The body angle and airspeed of free‐flying Drosophila hydei were measured and found to be inversely related. Values for the forces produced by a fly in level flight were calculated from the measured body angles, using published information from tethered fliers. The drag varied linearly with airspeed. The measured groundspeed of free fliers increased with starvation, not because of the change in weight and thus in the power‐to‐weight ratio, but through behavioural regulation of power output.
Regulation of haemolymph sodium and potassium during dehydration in the cricket Teleogryllus oceanicus
Authors: HYATT A. D. , MARSHALL A. T.
Published: March 2008

ABSTRACT. Male crickets (Teleogryllus oceanicus) when dehydrated for 3 days lost 51% of their body water, and 65% of their haemolymph volume. Haemolymph osmolality rose from 391 to 572mOs/kg; [Na+] from 149 to 289 HIM; and [K+] from 13.0 to 26.3 mM. During dehydration 385 μig Na (expressed as NaCl) and 41 μug K (expressed as KCI) were removed from the haemolymph. Rehydration of the dehydrated insects failed to restore the Na+ and K+ concentrations to near their original levels. Approximately 62% of the missing Na+ was excreted, whilst five times the amount of K+ removed from the haemolymph was excreted. It is presumed that the excess represents K+ removed from intracellular fluid.
Changes in the circadian flight activity of the mosquito Anopheles gambiae in relation to insemination, feeding and oviposition
Authors: JONES M. D. R. , GUBBINS S. J.
Published: March 2008

ABSTRACT. The effects of different physiological inputs on the circadian pattern of flight activity were examined in Anopheles gambiae. Males and virgin females had a similar activity pattern in which the initial (light‐off) peak accounted for a large proportion of the total activity. Starvation caused an increase in activity, but the basic pattern remained unchanged. After insemination, the initial peak in females was greatly reduced, while activity later in the dark phase increased. Blood‐feeding was followed by a depression of activity for 2–3 days, but there was an increase in the relative importance of the initial peak until oviposition had taken place. These changes are consistent with the switches in behaviour in the wild, from mating to host‐seeking, and then between host‐seeking and oviposition. Our results suggest that the changes are brought about by factors which have differential effects on the components of the circadian pacemaker.
The oviduct musculature of the horsefly, Tabanus sulcifrons, and its response to 5‐hydroxytryptamine and proctolin
Authors: COOK BENJAMIN J. , MEOLA SHIRLEE
Published: March 2008

ABSTRACT. A delicate lace‐like membrane covers the ovaries of Tabanus sulcifrons. These membranes were found to contain muscle fibres that provide the organs with motile properties. The lateral oviducts consist of a single layer of longitudinal muscles that form a structural syncytium by means of an extensive anastomosis of the fibres comprising it. The common oviduct is composed of two muscle layers, an outer sheath of circular muscle and an inner substratum of longitudinal muscle. Both of these layers showed evidence of a structural syncytium. When isolated in saline, the oviduct was spontaneously active and gave a simple phasic pattern of contraction. Such muscle preparations were sensitive to both 5‐hydroxytryptamine (5HT) and the insect myotropic peptide, proctolin. Excitation was generally indicated by a rise in muscle tonus or an increase in the frequency and amplitude of individual phasic contractions, or all three characteristics. The threshold for activation with 5HT was variable, ranging from as low as 4 × 10‐9M to 1 × 10‐7M. Proctolin evoked a noticeable increase in the tonus of most oviducts at 10‐10M. However, several preparations responded to as little as 3 × 10‐11M proctolin.
Precocene is not a specific antigonadotropic agent in adult female Aedes aegypti
Authors: KELLY THOMAS J. , FUCHS MORTON S.
Published: March 2008

ABSTRACT. In the mosquito, Aedes aegypti, other workers have shown that prior to blood‐feeding a pre‐vitellogenic period ensues manifested by the growth and differentiation of ovarian follicles. This results in resting stage follicles which will then complete ovarian development after the blood‐meal. Allatectomy of newly emerged females prevents follicles from reaching their resting stage and such follicles do not undergo subsequent vitellogenesis after blood‐feeding. Precocene II, a plant substance which effectively prevents ovarian development in Oncopeltus fasciatus by causing the irreversible degeneration of the corpus allatum, was applied to newly emerged mosquitoes, and at various times after blood‐feeding. Sublethal doses of precocene applied 1 h after adult emergence had no effect on pre‐vitellogenic follicular development and did not prevent yolk deposition after the blood‐meal. Precocene applied after blood‐feeding had two major effects. When administered early, it inhibited trypsin synthesis and retarded ovarian maturation. Animals exposed to it later, exhibited abnormal oviposition. It is proposed that precocene II does not act as an antigonadotropic agent in adult Aedes aegypti, but that it does induce a general toxic state in treated animals.
Ovarian development in the stable fly, Stomoxys calcitrans, in relation to diet and juvenile hormone control
Authors: MOOBOLA S. M. , CUPP E. W.
Published: March 2008

ABSTRACT. When female Stomoxys calcitrans were supplied a daily blood‐meal their polytrophic ovaries developed and deposited yolk, whereas those of females fed only 5% sucrose deposited no yolk and remained in a ‘resting’ condition. Longevity of the sugar‐fed flies was also reduced. Blood feeding was thus obligatory for general metabolism as well as reproduction. The follicles did not develop in females allatectomized within 1 h of emergence, irrespective of diet, and degenerated if blood was not provided. If blood was available the follicles did not degenerate, nor did they accumulate yolk. In both circumstances development was restored by implanting corpora allata. If allatectomy was delayed until 72 h after eclosion the follicles of sugar‐fed flies developed to the resting stage, and those of blood‐fed flies deposited yolk.
Abdominal stretch in the regulation of protein ingestion by the black blowfly, Phormia regina
Authors: BELZER W. R.
Published: March 2008

ABSTRACT. Negative feedback to protein feeding by Phormia is transmitted to the brain via the abdominal nerve. The inhibition is apparently generated by stretch receptors in the abdominal wall. This feedback makes a protein meal self‐limiting, supplying progressively more inhibition as the fly's swelling crop enlarges the abdomen during a meal. Abdominal stretch resulting from a mature egg mass also inhibits protein feeding by gravid females. This stretch seems to terminate protein feeding ‘prematurely’, leaving the female ‘primed’ to consume protein as soon as abdominal stretch is relaxed. The adaptive value of such a mechanism can be envisioned when one notes that the abdominal stretch normally will be relaxed only at a source of proteinaceous material, where the female lays her eggs. This would permit the fly to take advantage of the protein source before she flies away. The amount of protein consumed at such a time would normally be greater than the total amount stored in the fat body, thereby providing an important contribution toward the development of the next batch of eggs.
Caste and colony variations in the chemical composition of the cephalic secretions of the African weaver ant, Oecophylla longinoda
Authors: BRADSHAW J. W. S. , BAKER R. , HOWSE P. E. , HIGGS M. D.
Published: March 2008

ABSTRACT. Considerable differences were found in the composition of the volatile cephalic chemical of the castes of Oecophylla longinoda. The mandibular glands of minor workers contain a series of primary alcohols, predominantly 1‐hexanol, 1‐octanol and 1‐nonanol, together with nerol and geraniol. Hexanal, 2‐butyl‐2‐octenal and 3‐undecanone (components of the mandibular gland secretion of major workers, and which are important stimuli in alarm communication) are absent. Major workers are attracted and arrested by high concentrations of nerol, which is part of a possible mechanism for communication within the nest. The heads of males contain a pungent secretion, which may be used in defence; the major constituents are five aliphatic acids. The quantities of both main and trace constituents of the mandibular gland secretion of major workers were found to vary between colonies collected in different areas of West Africa.
Analysis of impulse rate and impulse frequency spectrum in the grasshopper, Omocestus viridulus, during adult development
Authors: KUTSCH W. , SCHIOLTEN P.
Published: March 2008

ABSTRACT. In the grasshopper O.viridulus, two song parameters were analysed during post‐larval ontogeny. The impulse rate (i.e. the rate at which the femur pegs strike the forewing vein) shows a modulation during up‐ and downstrokes of the hindleg. During post‐larval development there is no detectable change in characteristic impulse intervals, indicating a constancy of the hindleg‐stroke movement irrespective of age. The impulse frequency spectrum also shows considerable constancy during post‐larval ontogeny. Apparently, the main song features, including the underlying motor pattern, are completed with the early song productions of the adult.
Termination and reinduction of reproductive diapause by photo‐period and temperature in males of the grasshopper, Oedipoda miniata
Authors: ORSHAN L. , PENER M. P.
Published: March 2008

ABSTRACT. Previous publications have demonstrated that O.miniata adults exhibit an aestival reproductive diapause during the dry summer in Israel; females do not lay and males show only little mating behaviour. It was also reported previously that photoperiod and temperatures corresponding to autumn in Jerusalem terminate diapause and induce intense male mating behaviour, whereas continuous illumination and high temperatures maintain diapause. In the present study we used mating behaviour as an indicator for investigating the effects of several photoperiod—temperature combinations on reproductive diapause in O.miniata males. Mating behaviour was induced and diapause terminated under the following conditions: LD 10.5:13.5, T = 38‐27°C (the temperatures during the photophase and scotophase, respectively); LD 12:12, T=38–27°C; LD 12:12, T=26–13°C; LD 14:10, T = 26–13°C. In contrast, diapause was maintained under LD 14:10, T = 38–27°C and under LL with high but variable temperatures. In further experiments males that were already sexually active, and which had been kept under LD 12:12, T = 38–27°C, were transferred to LL with high variable temperatures. Similarly, postdiapause males which had been kept under LD 14:10 and T=26–13°C were transferred to T = 38–27°C without changing the photoperiod. In both instances mating behaviour declined, then disappeared, thus reinduction of the diapause occurred under such conditions which previously were found to maintain diapause. O.miniata is therefore a ‘short day’ and/or ‘low temperature’ insect. This is the first report on complete control of photoperiod—temperature over aestival reproductive diapause and its reversibility in a male insect.
Corpus allatum function during sexual maturation of male Diploptera punctata
Authors: TOBE STEPHEN S. , MUSTERS ADRIAN , STAY BARBARA
Published: March 2008

ABSTRACT. The effect of allatectomy on synthesis of accessory reproductive gland secretion, spermatophore production and sexual behaviour in male Diploptera punctata was investigated during the first 6 weeks of adult life. After allatectomy, synthesis of the secretion and production of spermatophores was slightly reduced relative to sham‐operated animals (by 16%), but not relative to normal animals. However, sexual behaviour of the operated animals appeared normal. Thus, the corpora allata (CA) may not be necessary for the sexual functioning of male D.punctata. The synthesis of C16 juvenile hormone (C16 JH; JH III) by isolated pairs of CA from individual males was followed during this period and, at all times, the rate of synthesis was less than 8pmolh‐1 per pair, a rate similar to that observed in pregnant females. The significance of this continued synthesis of JH by male CA is unknown, although it may be related to the maintenance of general metabolic activities.
Long‐term changes in the oviposition behaviour of the cabbage butterfly, Pieris rapae, induced by contact with plants
Authors: TRAYNIER R. M. M.
Published: March 2008

ABSTRACT. Contact between the tarsi and cabbage foliage was found to have important influences on the oviposition behaviour of Pieris rapae, whereas contact between the ovipositor tip and cabbage foliage showed no influence. Oviposition on a leaf disc was not influenced by the presence of previously laid eggs. Gravid female P.rapae showed an increased tendency to approach and land on host or non‐host foliage, or on yellow or green cards, after tarsal contact with cabbage foliage. This effect persisted for at least 72h. It was accompanied by an increased tendency to oviposit on non‐host plants, most obviously within seconds of contact with cabbage, but with some persistence after 72h. Contact with a non‐host leaf (lettuce) reduced the tendency of females to land on plants, but this effect was less pronounced than the one induced by contact with cabbage. These behavioural changes were immediate as well as long‐term and were not associated with changes in the ovaries, so they probably result from the direct effects of sensory input on the CNS. Such behaviour probably increased the likelihood that gravid females would locate host‐plants for oviposition in the field. For tests of host‐plant specificity, the implications are that the behaviour of gravid females towards an array of plants might differ according to the presence or absence of hosts, not only during the test, but also during the preceding several days.
A comparison of the correcting behaviour exhibited by two milkweed bugs, Oncopeltus fasciatus and Lygaeus kalmii
Authors: ALLER TOM , HIRAI DENISE , CALDWELL ROY L.
Published: March 2008

ABSTRACT. Adults and nymphs of two species of milkweed bugs, Oncopeltus fasciatus and Lygaeus kalmii, were studied with respect to their optomotor responses, as exhibited by the laboratory phenomenon of correcting behaviour on mazes. It was found that the O.fasciatus nymphs failed to correct while the other three groups all exhibited correcting behaviour. The differences in correcting behaviour were attributed to differences in such ecological variables as degree of socialness, nature of food source, and foraging strategies.
Mating behaviour in the mosquito, Anopheles gambiae s.1.save
Authors: CHARLWOOD J. D. , JONES M. D. R.
Published: March 2008

ABSTRACT. Mating behaviour in the Anopheles gambiae complex was studied in the laboratory, using an infra‐red TV system to make observations in the ‘dark’. Maximum fertilization occurred when both sexes were at least 2 days old. In LD 12:12 most mating took place in the first hour of the dark phase. At this time, the males had erect fibrillae on the antennae and showed the maximum response to an artificial female flight tone, approaching, landing‐on and attempting to clasp the sound source. The cycle of fibrillar erection and of responsiveness to sound continued in constant dark. Males did not appear to discriminate on contact, between their own and other species. Previously mated females actively resisted copulation, but, when tethered, were unable to prevent the deposition of further internal mating plugs. Free‐flying, previously inseminated, females prevented the males from depositing internal plugs, but not from ejaculating and depositing external plugs. The differences between A.gambiae and the better known Stegomyia mosquitoes appear to be related to their different habits, A.gambiae males being less likely to encounter females of other species or inseminated females of their own species at the restricted time and place of mating.
Oligophagy and absence of food‐aversion learning in tobacco hornworms, Manduca sexta
Authors: DETHIER V. G. , YOST M. T.
Published: March 2008

ABSTRACT. Temporary illness can be induced in tobacco hornworms, Manduca sexta, by feeding them on Atropa belladonna or Nerium oleander that have been sprayed with insecticides, or by feeding them on unsprayed Petunia. Behavioural preference tests showed that recovered larvae did not avoid the plants that induced illness. Thus, these larvae did not exhibit food‐aversion learning of the kind demonstrated in phytophagous terrestrial slugs and in vertebrates. The ecological significance of these results is discussed.
Comparison of effects of juvenile hormone mimic and synthetic juvenile hormone I on the bug Lygaeus kalmii
Authors: HUNT LINDA‐MARGARET
Published: March 2008

ABSTRACT. The possibility that JH mimics cause artifactual responses was investigated by comparing one such mimic (JH‐M) and a ‘true’ JH (JH I) in the effects of each upon L.kalmii larval colouring and development. Post‐blastokinesis treatment with synthetic JH I affected larval colour pattern in the same way as JH‐M, but higher hormone concentrations were required. JH I also caused higher larval mortality. JH‐M and JH I were equally effective in producing supernumerary instars.
Tactile orientation by mating males of the staphylinid beetle, Aleochara curtula, relative to the setal fields of the female
Authors: PESCHKE K.
Published: March 2008

ABSTRACT. In contact orientation on the female, the male Aleochara curtula moves its tongs‐shaped parameres to the tip of the female's abdomen. The male is directed by tactile stimuli from the direction of the setae on the female. These setae are distributed over the female's entire surface, and their additional function as a guide in the complex sex specific orientation system has not caused detectable structural specialization.
A circadian rhythm in spontaneous locomotor activity in the larvae and pupae of the mosquito, Culiseta incidens
Authors: CLOPTON JOSEPH R.
Published: March 2008

ABSTRACT. The spontaneous locomotor activity of the larvae of Culiseta incidens was monitored with acoustic actographs. Individuals, in water resting on the cones of the speakers, displayed an activity rhythm in LD 12:12 with peak activity in the light phase. A similar rhythm occurred in DD following rearing in either LD 12:12 or LL, with free‐running periods of 23.5–24 h. No evidence was found of any consistent differences between the periods of the larvae and pupae. The amplitude of the pupal rhythm gradually increased as metamorphosis progressed. It is suggested that rhythmicity might also be found in those behavioural responses of mosquito larvae and pupae which have been the subject of previous studies.
Height control by free‐flying Drosophila
Authors: DAVID C. T.
Published: March 2008

ABSTRACT. In a horizontal wind tunnel, Drosophila flew at almost constant height along tracks up to 2 m long. The flies rose or sank only slowly when it was so dark that they no longer responded to movements of the tunnel floor, suggesting that their height control is mediated, at least partly, by responses to their movement relative to the air. In the light, the flies maintained height better than in the dark and were very responsive to movements around them. They faithfully followed the up and down movements of horizon screens at their sides whether they were flying in still air or against a wind, even in the presence of many other stationary visual cues. The flies did not respond by compensatory height changes to real vertical movements of a patterned horizontal disc beneath them, nor to changes in the size of the floor pattern. They did respond to horizontal acceleration of the floor pattern in the direction opposite to their flight (optically simulating a descent by the fly), by an apparently compensatory increase in height, but they also rose (instead of sinking) in response to floor acceleration in the direction of their flight. When the floor was accelerated in either direction they showed compensatory groundspeed‐controlling responses. The increases in height might be alarm responses to sudden movements in the visual field beneath them. Both speed and height changing responses to floor movement were reduced when the number of stationary visual cues was increased. Drosophila thus control their height mainly by responses to the apparent movement of nearby visual cues at round about their own height.
Studies on l‐glutamate in insect haemolymph.
Authors: IRVING S. N. , WILSON R. G. , OSBORNE M. P.
Published: March 2008

ABSTRACT. l‐Glutamate when injected into the haemolymph of Lucilia sericata larvae and adult male Locusta migratoria was rapidly removed by uptake mechanisms to other tissues in the insect. Data from Lucilia larvae indicate that following uptake glutamate is metabolized and the metabolites are secreted back into the haemolymph. l‐Aspartate injected into the haemolymph of Lucilia larvae was also rapidly removed. When both l‐aspartate and l‐glutamate were injected simultaneously, the rate of glutamate removal was significantly reduced. It is concluded that glutamate and aspartate share the same uptake mechanisms. l‐Leucine injected into Lucilia larvae and Locusta was removed at a significantly slower rate than glutamate or aspartate.
Studies on l‐glutamate in insect haemolymph.
Authors: IRVING S. N. , WILSON R. G. , OSBORNE M. P.
Published: March 2008

ABSTRACT. Glutamate was detected in the haemoplasm of adult male Periplaneta americana, adult male Schistocerca gregaria, adult male Locusta migratoria, larval Calliphora erythrocephala, larval Lucilia sericata and Carcinus maenas, in all cases at low concentrations only, i.e. below 10‐5M. This was confirmed by high‐voltage paper electrophoresis and, in the case of Lucilia sericata larvae, by the lack of pharmacological activity of the haemolymph. Glutamate was detected in appreciable concentrations in the haemocytes of all the arthropods analysed. It was found that levels of glutamine in the haemoplasm increased if the haemolymph had started to clot, if the haemolymph had been inadequately centrifuged, if the haemolymph was contaminated by other tissues and if acid protein precipitants were used which hydrolysed glutamine to glutamate. This finding removes a major argument against the acceptance of l‐glutamate as a neuromuscular transmitter.
Neural function in an alpine grylloblattid: a comparison with the house cricket, Acheta domesticus
Authors: MORRISSEY R. , EDWARDS JOHN S.
Published: March 2008

ABSTRACT. The effect of temperature on evoked activity in giant interneurons was compared in Grylloblatta sp. (an alpine insect with a temperature preference close to 0°C) and Acheta domesticus. The response to sound and air‐puff stimulation of the abdominal cerci was monitored with extracellular electrodes placed under the ventral nerve cord. Responses to air puffs were elicited in Grylloblatta while the animal was supercooled to ‐6°C. The supercooling point was reached and freezing occurred in the range ‐5.5 to 8.5°C. The upper extinction temperature could not be determined due to massive spontaneous giant fibre activity in the 12–15°C range masking responses to air puffs. Lethal heat coma occurred at 15–20°C, although most animals did not recover from the spontaneous CNS activity which preceded it. The extinction ranges for Acheta giant neurons were 3.5‐4.0°C and 42–44°C. Spike number peaked at 33–36 C and amplitude levels diminished as heat or cold coma was approached; ‐7.5 C was the mean supercooling point. Both species recovered from cold coma if supercooling was avoided; in Acheta, heat coma was also reversible. Giant fibre latencies in Acheta displayed a Q10 of 1.2 above 11–14°C, below which a break occurred in the curve and delays increased sharply. Latencies for the grylloblattid exhibited a Q10 of 2 but no break in the curve was observed until 0° C was approached. Spike number and amplitude increased with temperature until spontaneous CNS activity obliterated responses to air puffs. The potential role of unsaturated fatty acids in low temperature adaptation in Grylloblatta is discussed.
Mating behaviour in Oncopeltus fasciatus: circadian rhythms of coupling, copulation duration and ‘rocking’ behaviour
Authors: WALKER WILLIAM F.
Published: March 2008

ABSTRACT. Circadian rhythms are demonstrated in initiation and duration of copulation, and in ‘rocking’ by females during mating in the large milkweed bug, Oncopeltus fasciatus. In constant light or darkness there were no more than two or three recognizable cycles of any of these rhythms. In addition, light directly stimulated copulatory attempts, but did not influence their chance of success. Copulations were generally shorter during the early‐mid photophase and longer during the late photophase in LD 16:8, while initiations of copulation were fewest during the scotophase. The males were mainly responsible for these rhythms. It is suggested that the diurnal rhythm in copulation duration probably evolved as a consequence of the rhythms of flight activity and/or oviposition. Sperm from the late photophase matings typically displaced 90–100% of sperm from prior matings, while sperm from the shorter early photophase matings typically displaced less prior sperm. Peak rocking activity during mating occurred from 6 to 8 h after lights‐on in LD 16:8. Little rocking occurred during the late photophase, when the greatest percent of pairs are in copula. Feeding and drinking inhibited rocking activity, but the feeding rhythm did not drive the rocking rhythm. Rocking appears not to function in promoting termination of mating, positioning of the aedeagus, nor to mediate mechanical stimulation of egg production. Its function remains unknown.
An investigation of the possible presence of an aggregation pheromone in the milkweed bugs, Oncopeltus fasciatus and Lygaeus kalmii
Authors: ALLER TOM , CALDWELL ROY L.
Published: March 2008

ABSTRACT. The presence of an aggregation pheromone was studied in two species of milkweed bugs. The nymphs, young adults and old adults of Oncopeltus fasciatus were tested for their aggregation in response to acetone extracts of themselves and each other. The O. fasciatus nymphs were also tested for their response to odour from live O. fasciatus nymphs, as well as to Lygaeus kalmii nymphal extract, and the response of L. kalmii nymphs towards O. fasciatus nymph extract was tested. It was found that there is an aggregation pheromone in the nymphs and young adults and that there may be an alarm pheromone in the old adult O. fasciatus. A preliminary chemical analysis performed on the aggregation pheromone revealed it probably to be a polar non‐aromatic compound of high molecular weight.
Effect of diet on the neuroendocrine system and egg development in the sheep blowfly, Lucilia sericata
Authors: APPLIN D. G.
Published: March 2008

ABSTRACT. A light microscope study of the endocrine and ovarian systems of Lucilia sericata under two diets revealed that in young females fed on sugar and water, medial neurosecretory cells (MNC) synthesized and stored neurosecretory material (NSM) as the flies matured. The MNC remained filled with NSM as long as the diet was maintained. Following a small increase immediately after emergence, the size of the corpora allata (CA) showed little further change, and the nuclei of nurse cells remained small. However, rapid changes occurred in these tissues soon after a meat meal: NSM was discharged from the MNC, and the CA increased in size. These changes were at a maximum 20 h after a meat meal. 4h later, vitellogenesis was well established and the nurse cell nuclei had increased in size 20‐fold. Growth of the nurse cell nuclei continued until approximately 6 h before the completion of vitellogenesis when they are resorbed. Oögenesis took about 48 h at 25°C. When 100 μg of each of three different juvenoids were applied topically to different sugar‐fed flies, the nuclei of both MNC and nurse cells became enlarged, whereas the CA were somewhat reduced in size. The relationship between protein ingestion and oogenesis is discussed, and the results obtained with L. sericata are compared with those of other species, especially the blowfly Calliphora erythrocephala.
Circadian activity patterns in three species of tsetse fly: Glossina palpalis, austeni and morsitans
Authors: CRUMP ANDREW J. , BRADY JOHN
Published: March 2008

ABSTRACT. Observations on the nature and control of spontaneous flight activity in tsetse flies have so far been made only on G. m. morsitans Westw. This paper reports preliminary observations of the same kind on two other species: G. p. palpalis (R.‐D.) and G. austeni Newst. The flight pattern of all three species consisted of short bursts of activity (usually lasting <1 min) separated by long intervals of rest, changes in activity level occurring exclusively as changes in the frequency of these flight bursts. In constant conditions in LD 12:12, G. palpalis and G. austeni were almost totally diurnal, with strongly predominant afternoon activity peaks, but a slight tendency to decrease activity around noon as occurs to a much greater extent in G. morsitans. This rhythm persisted in constant darkness (DD), but whereas in most G. morsitans only the morning peak was retained in DD, in G. palpalis and G. austeni it was only the afternoon peak. The loss of the afternoon peak in G. morsitans may be due to the very low activity levels in DD. Food deprivation led to increased activity in all three species, most markedly so in G. palpalis and G. austeni, in which the amount of activity per day increased c. ten‐fold over three days' post‐emergence starvation.
Influence of ecdysterone, precocene and compounds with juvenile hormone activity on induction, termination and maintenance of diapause in the parasitoid wasp, Nasonia vitripennis
Authors: LOOF A. DE , LOON J. VAN , VANDERROOST C.
Published: March 2008

ABSTRACT. Using the Galleria bioassay, no difference could be found between the JH titre of diapausing and developing Nasonia larvae. Compared to the values found in some Lepidoptera, the JH titres in Nasonia larvae are low, c. 14 Galleria units/g live weight. Induction of diapause could not be brought about by topical application of JH I, JH analogues, precocene, or ecdysterone to the maternal generation, nor by treating eggs or larvae with compounds with JH activity. Diapause was easily terminated by topical application of ecdysterone, however. If ecdysterone treatment was preceded by JH‐treatment, the percentage of larvae terminating diapause was reduced: JH II seems to be more potent than JH I or JH III in this effect if the interval between JH and ecdysterone treatment is 72 h.
The role of feedback during singing and flight in Drosophila melanogaster
Authors: EWING ARTHUR W.
Published: March 2008

ABSTRACT. During Drosophila courtship ‘pulse song’, muscle potentials occur at two points during the cycle of neuromuscular events which result in a sound pulse being produced. The dorsal longitudinal, second and third dorsal ventral and axillary muscles show potentials 18 ms before each sound pulse while the first dorsal ventral, basalar and sternobasalar muscles fire 3 ms after the onset of each pulse. The timing of these events remains unaltered in animals with the antennae removed, indicating that acoustic feedback is not an important factor. Courting vestigial flies, in the absence of detectable wing base movements, produce indirect muscle potentials at the appropriate song inter‐pulse intervals. Thus proprioceptive feedback is also unimportant in determining the intervals between pulses. During putative ‘sine song’, ‘pulse song’ and flight in vestigial flies, however, the timing of basalar muscle potentials is abnormal. Also, if the wing is driven externally at a frequency different from that of normal flight, basalar and, to a lesser extent, first dorsal ventral muscles, are phase locked to the driving frequency. These two results suggest that the timing of those muscles which fire at the beginning of the sound pulses is set by proprioceptive feedback. A model of song production is proposed which takes into account the data from this and from previously published papers.
Techniques for studying honeybee pheromones involved in clustering, and experiments on the effect of Nasonov and queen pheromones
Authors: FERGUSON A. W. , FREE J. B. , PICKETT J. A. , WINDER M.
Published: March 2008

ABSTRACT. Techniques for investigating pheromones responsible for clustering in Apis mellifera are described. Stable queenless clusters were formed in response to synthetic Nasonov pheromone mixed with (E)‐9‐oxo‐2‐decenoic acid. This mixture plus the addition of (E)‐9‐hydroxy‐2‐decenoic acid was less potent in initiating cluster formation than it was without this addition, but the clusters once formed sometimes grew larger. Other unknown components from the queen's mandibular glands encouraged cluster formation.
Copulatory behaviour of the potato tuber moth, Phthorimaea operculella
Authors: ONO TOMOHIRO
Published: March 2008

ABSTRACT. Copulatory behaviour of the potato tuber moth, Phthorimaea operculella, was observed in a small glasshouse. The behavioural chain is started by the female ‘calling’. Males responded to the female's sex pheromone by searching in her vicinity. When the males ‘recognized’ the female, they attempted copulation. This behaviour was released, however, by a wide variety of models, including dried whole male and female bodies, similarly sized rolls of paper with male or female wings attached, rolls of paper covered in wing scales, and even flat surfaces covered in wing scales (provided the surface was much larger than a moth). It is concluded that the mechanical stimulus from the scales is an important stimulus for evoking copulation.
Control of pheromone production in the bark beetle, Ips cembrae
Authors: RENWICK J. A. A. , DICKENS JOSEPH C.
Published: March 2008

ABSTRACT. Exposure of newly emerged Ips cembrae adults to myrcene vapour resulted in the production of ipsenol and ipsdienol by males, in quantities comparable to those found during natural attack of larch trees. Treatment of male beetles with juvenile hormone analogue (JHA) triggered production of 3‐mefhyl‐3‐buten‐l‐ol, the third component of the aggregation pheromone complex. The beetles are therefore capable of producing ipsenol and ipsdienol immediately upon contact with host resin, whereas methylbutenol production appears to be hormonally controlled upon the initiation of feeding. Beetles exposed to the enantiomers of ipsdienol apparently utilized only (R)‐(—) ipsdienol to synthesize ipsenol, suggesting a high degree of chiral selectivity.
Experiments on biting and gorging behaviour in the black fly, Simulium venustum
Authors: SUTCLIFFE JAMES F. , McIVER SUSAN B.
Published: March 2008

ABSTRACT. Factors which initiate ‘biting’ (i.e. probing, piercing and tasting collectively) and gorging responses, were studied in the black fly, S. venustum using an artificial feeding method. A positive relationship was found between biting activity and the magnitude of the temperature differential between the feeding surface and the air above it. Although many investigators consider temperature to be a probing stimulus, it is argued that an equally consistent interpretation could regard temperature as only a very short range host‐location cue. The stimulus to probe could be contact with the feeding substrate. Of the compounds tested as gorging stimulants ATP and ADP proved most potent, followed by AMP and adenosine, followed by cAMP. The compounds GTP, CTP and UTP were all on the borderline of statistical significance as gorging stimulants. It is suggested that the host‐location phase, including the biting responses, represents appetitive behaviour leading to the consummatory response of repetitive pumping (gorging) stimulated by ATP, etc.
Effects of the ingestion of components of a protein‐rich diet on the sexual receptivity of females of the Australian sheep blowfly, Lucilia cuprina
Authors: BROWNE L. BARTON , GERWEN A. C. M. VAN , CSIRO R. J. BARTELL
Published: March 2008

ABSTRACT. A high level of sexual receptivity was displayed by females of Lucilia cuprina (Wied.) following the ingestion of a known amount of a standard preparation of a protein‐rich material (liver exudate), in addition to sucrose and water. A similarly high level of receptivity resulted from the ingestion of bovine serum albumin (BSA) plus a low molecular weight (MW) fraction of the liver exudate, or BSA plus an inorganic salt mixture, provided that the amount of BSA ingested equalled that of protein in the ingested exudate, the amount of low MW fraction was the same as that in the exudate, and the ingested salt mixture contained the same amounts of Na+, K+, Mg++ and Ca++ as were in this amount of low MW fraction. Substantial but less pronounced increases in receptivity followed the ingestion of equivalent amounts of BSA or low MW fraction alone. Receptivity was slightly increased by the ingestion of the inorganic salt mixture. When females were fed smaller quantitatively equivalent amounts of liver exudate or one or other of the two mixtures in the presence of low MW components, BSA was as effective, in inducing receptivity, as the high MW (protein) fraction of liver exudate, and the salt mixture was as effective as the low MW fraction when ingested together with protein. Receptivity correlated well with the mean ovarian developments of the groups of females which fed on the different materials. However, some lack of correlation at the level of individuals indicates that the control mechanisms for the two are at least partially distinct.
The imaginal ecdysis of the desert locust, Schistocerca gregaria.
Authors: HUGHES T. D.
Published: March 2008

ABSTRACT. The imaginal ecdysis of the desert locust, Schistocerca gregaria (Fo̊rsk.), is described in detail. Ecdysis is considered to begin when the fifth instar nymph ceases to feed and to end when the adult takes its first meal. It is here divided into six stages: Stages 1 and 2 constitute the pre‐emergence behaviour; Stages 3 and 4, emergence; Stage 5, the expansion of the new cuticle; and Stage 6, the post‐expansional behaviour.
Quantitative food utilization and reproductive allocation by adult milkweed bugs, Oncopeltus fasciatus
Authors: SLANSKY FRANK
Published: March 2008

ABSTRACT. Age‐specific and lifetime dry mass budgets were estimated for mated and virgin adult milkweed bugs, Oncopeltus fasciatus (Dallas) Hemiptera: Lygaeidae), fed air‐dried milkweed seeds (Asclepias syriacd) in the laboratory at LD 14:10 and 23°C. Relative consumption rate (RCR) of all bugs was high during the first 8 days posteclosion (teneral period) as their fresh weight, dry weight, and fat content increased. Thereafter, the physiological syndrome associated with reproduction in mated females was indicated by their higher RCR, earlier and greater rate of egg production, greater lifetime relative metabolic rate and higher net and gross production efficiencies than virgin females and males. Males tended to live longer than virgin and mated females, which had similar lifespans. Mated females weighing less at eclosion remained lighter in weight on the day of mean peak weight, but food consumption, egg production and lifespan were independent of body‐weight over a 25% range. Input of nymphal reserves or male reproductive secretions to egg production is probably minor in comparison with the adult female's food budget. The high proportion of the food budget allocated to egg production by mated females of O.fasciatus is consistent with its migratory, colonizing lifestyle.
The origin of free glycerol accumulated in diapause eggs of Bombyx mori
Authors: YAGINUMA TOSHINOBU , YAMASHITA OKITSUGU
Published: March 2008

ABSTRACT. The origin of free glycerol in diapausing eggs of Bombyx mori was examined using 14C‐glycerol as a tracer. When 14C‐glycerol was injected into 5‐day‐old female pharate adults to label the egg lipids, radioactivity was recovered in glycogen as well as in total lipids in newly laid eggs, but the specific radioactivity in lipid glycerol was 2.5 times higher than that in glycogen. When eggs entered diapause, radioactivity in glycogen decreased rapidly and a concomitant accumulation of sorbitol occurred, implying the conversion of glycogen into sorbitol at the initiation of diapause. Radioactivity in total lipids decreased slowly but significantly, and in free glycerol increased steadily during the diapause period. The sum of recovered radioactivity in these components remained almost constant throughout diapause. The specific radioactivity (cpm/C‐atom) of free glycerol was clearly lower than that of lipid glycerol but higher than that of glycogen or sorbitol. It was calculated that about 30% of free glycerol was derived from lipid glycerol in the diapausing eggs.
Aggregation in the questing tick, Rhipicephalus pulchellus
Authors: BOER J. DEN , BOER M. H. DEN
Published: March 2008

ABSTRACT. The ixodid tick, Rhipicephalus pulchellus (Ixodidae) can be observed aggregated on the tips of grass stems in the field in Kenya. From laboratory experiments, Browning (1976) concluded that these aggregations were the result of ticks having first aggregated on the ground if provided with sufficient cover. During our extension of Browning's experiments using several types of cover, the ticks did not exhibit aggregating behaviour. The influence of the presence of a human observer on the activity of the ticks, however, became apparent.