bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acoustic behaviour of both sexes of the speckled bush cricket Leptophyes punctatissima
Authors: HARTLEY J. C. , ROBINSON D. J. 
Published: March 2008

AbstractAs in other phaneropterine bush‐crickets, both male and female Leptophyes punctatissima can stridulate. Stridulation in the female, which had previously been overlooked, occurs in response to the male call. The main frequency of the very brief chirps is around 40 kHz. The male is stimulated to chirp more frequently by receiving response chirps from the female. Unlike most Tettigoniidae the male moves toward the female and is thus dependant on her response signal. Communication can occur over distances of at least 5 m. Some structures involved in stridulation in the female differ from that described in other phaneropterines.The insects used in these experiments were all reared in the laboratory from wild‐caught parents. Between forty and fifty different insects were used at various times for laboratory studies on the song, and four different males and three females were used on the field communication experiments. The sexes were kept separate from the moult to adult or for at least 10 days before experiments.
Song modification in the Orthoptera I. Proclamation songs of Platycleis spp. (Tettigoniidae)
Authors: SAMWAYS MICHAEL J. 
Published: March 2008

AbstractOrthopteran song terminology is briefly reviewed taking into account new proposals concerning the term ‘chirp’ by Broughton (1976). The song of Platycleis intermedia is analysed in detail. Synchronous or unison singing between conspecifics of this species is maintained, despite ambient temperature differences, by the individual at the lower temperature instantaneously extending its echeme interval. The normal songs of P.afinis, P.falx, P.sabulosa and P.albopunctata are described and compared with each other and with the song of P.intermedia. The songs of all five species are similar at the syllable level but different at the echeme level. It appears to be these similarities and differences that are responsible for song modification on the part of P.intermedia when it hears the song of one of the other four species.
The effect of enforced virginity and subsequent mating on the activity of the corpus allatum of Periplaneta americana measured in vitro, as related to changes in the rate of ovarian maturation
Authors: WEAVER ROBERT J. , PRATT GRAHAME E. 
Published: March 2008

ABSTRACT. Female P. americana, reared with males from the time of adult emergence, mated on the 4th–5th day after metamorphosis, produced the first ootheca on the 8th or 9th day, and then produced successive oothecae at intervals of 3.0 days, whereas, only 50% of virgin females had produced their first ootheca by the 28th day after adult emergence. Examination of the ovaries indicated that oocyte development is normal in virgins until shortly after the time when they first become receptive to males. When mating was not allowed there was a dramatic reduction in the rate of vitellogenic growth of the terminal batch of oocytes which persisted until mating was allowed, and was often accompanied by resorption of a percentage of the oocytes.Short‐term, in vitro, radiochemical assay of juvenile hormone (JH III) biosynthesis by corpora allata (CA) showed that, in females reared with males, the cycles of ovarian development are accompanied by regular pulses of CA activity. There is a small, possibly preparatory peak of JH III biosynthesis before vitellogenesis of the first wave of oocytes, followed by a larger peak of JH III production during vitellogenesis of this batch of eggs and one peak of CA activity between ovulation of each subsequent wave of oocytes. Activities as low as 0.25 pmol C16JH/CA pair/h and as high as 48.38 pmol/CA pair/h were observed in CA from mated females after the onset of cyclic activity.Stimuli received during mating are somehow responsible for the cyclic activity of the CA, for when females were subjected to enforced virginity the first small peak was normal but the second peak was not fully realized and there was then a gradual decline in CA activity until approximately 2 weeks post‐emergence. Thereafter the glands exhibited a more or less constant rate of JH biosynthesis (mean = 3.45 ± 0.32 pmol/CA pair/h.) When females were mated after 21 days of enforced virginity the activity of the CA was enhanced. By 48 h after mating the mean glandular activity was at least four times that found in virgins of the same age, and by 72 h rates as high as 40 pmol/CA pair/h were observed. This was followed by normal cyclic activity of the CA. The increase in rate of JH biosynthesis appears to result in a recommencement of oocyte development in these ‘delayed‐mated’ females.
Walking and take‐off in Aphis fabae.
Authors: BINNS E. S. 
Published: March 2008

ABSTRACT. Illumination either from one side or alternating between the two sides induced aphids to turn towards the light and also delayed their take‐off as compared with illumination from the front. Illumination from in front or from both sides simultaneously delayed take‐off as compared with dorsal illumination and also increased the rate of walking. Take‐off was frequently induced by a change from frontal to dorsal illumination but not from lateral or ventral to dorsal. Ventral illumination delayed take‐off as compared with dorsal, but appeared to inhibit walking.In frontal illumination, rate of walking and time to take‐off were positively correlated when aphids walked on a cat‐walk, but negatively correlated on a smooth surface. Thus the two locomotory acts, walking and flight, could interact either as ‘allies’ or as ‘antagonists’, either one hastening or deferring the other in different conditions. Take‐off from a plant is discussed in terms of the interaction between these two locomotory responses, and ‘settling’ responses.
Control of ventilatory movements in the aquatic insect Corydalus comutus: central effect of hypoxia
Authors: KINNAMON SUE C. , KAMMER ANN E. , KIORPES ANTHONY L. 
Published: March 2008

ABSTRACT. The influence of hypoxia and hypercapnia on the ventilatory rhythm of the hellgrammite Corydalus cornutus L. (Megaloptera) was studied. In intact animals the frequency of rhythmic retractions and protractions of abdominal gills is increased by hypoxia (10% O2, 90% N2) but no ventilatory response is elicited by hypercapnia (1–5% CO2, 20% O2, 75–79% N2).The ventilatory motor pattern was examined by recording extracellularly from the gill retractor muscle or its efferent nerve. In response to hypoxia (8% 02, 92% N2), there are decreases in the cycle‐time, the interspike interval, and the burst length of the gill retractor motorneuron. In addition, previously quiescent motorneurons associated with gill protraction are recruited.Individual ganglia or small groups of abdominal ganglia can be isolated both from the central ganglionic chain and from the periphery by selective cutting of roots and connectives. When exposed to hypoxia, preparations that include the first abdominal ganglion show characteristic changes in the ventilatory motor pattern similar to those in intact animals. Thus sensitivity to oxygen appears to be located centrally and not peripherally. In small animals (head width < 7 mm), abdominal ganglia 2–3 and 2–7 respond characteristically to hypoxia, but in larger animals (head width > 9 mm), chains of ganglia lacking abdominal ganglion 1 fail to respond. In larger animals oxygen sensitivity may thus be concentrated in abdominal ganglion 1, whereas in smaller animals the ability to initiate a ventilatory response to hypoxia is distributed among the abdominal ganglia.
Uptake and loss of water in diapause and non‐diapause eggs of crickets
Authors: TANAKA SEIJI 
Published: March 2008

ABSTRACT. In laboratory‐laid eggs of the striped ground cricket, Allonemobius fasciatus DeGeer (Gryllidae), water absorption occurs at an early stage of embryogenesis (stage II) at 30°C but is delayed until later stages at lower temperatures. This is related to the variation in diapause stage at different temperatures. No egg developed beyond stage VII (the end of anatrepsis) without water absorption. A. fasciatus shows seasonal variation in the stage of water absorption. At 30°C, eggs collected in August absorb water at the early stage while many of those collected in September avert diapause and absorb water at a later stage.Diapause also influenced the water absorption of eggs in A. socius Scudder. Eggs of short‐day females enter diapause and absorb water at stage II, while those of long‐day females develop without diapause and absorb water at a later stage (around stage IV).The susceptibility to desiccation (r.h. 50%) was examined at 20°C with A. fasciatus eggs. The percentage water loss and mortality of eggs varied with the time and duration of exposure to desiccation. Eggs are most sensitive to desiccation during the first several days after being laid and during the period of water absorption.
Food intake, conversion efficiency, and feeding behaviour of tobacco hornworm caterpillars given artificial diet of varying nutrient and water content
Authors: TIMMINS W. A. , BELLWARD K. , STAMP A. J. , REYNOLDS S. E. 
Published: March 2008

ABSTRACT Fifth stadium tobacco hornworm caterpillars, Manduca sexta (L.), given artificial diet diluted to varying extents with either cellulose or water compensated for the food's reduced nutrient content by eating more of it. This compensation was, however, in most cases not sufficient to maintain normal growth rates. When the water content of the diet was reduced, the insects ate less than the usual fresh weight of food but maintained their intake of nutrients. Nevertheless, growth rate was impaired. The insects were better able to compensate for dilution of their food with water than with cellulose.The efficiency of conversion of ingested food (ECI) was decreased when the diet was adulterated with cellulose. At moderate dilution (50% nutrient) this was due mostly to decreased approximate digestibility (AD), but at greater dilution (25% and 10% nutrient content) the efficiency of conversion of digested food (ECD) was decreased. ECI was maintained when the water content of the diet was increased to give 50% nutrient concentration, but was decreased when water content was changed more radically (200%, 25% and 10% nutrient diets). This was due mostly to increased metabolic costs (decreased ECD) in all cases.The retention time of food in the gut was progressively decreased (i.e. speed of passage was increased) as nutrients were replaced by cellulose. By contrast, dilution of the diet with water resulted in only slight changes in retention time, except at extreme dilution (10% nutrient content) when retention time was reduced.Compensation of food intake was achieved by spending more (or less) time eating. Video analysis of feeding behaviour showed that there were significant changes in the length of feeding bouts and of interfeed gaps when caterpillars fed on diets of altered composition. For diets diluted with cellulose, changes in bout length and bout frequency contributed substantially to the increased time spent feeding on the adulterated food. For diets diluted with water, however, almost all of the compensatory change in behaviour was due to increased bout length, with bout frequency affected only slightly. This suggests that volumetric feedback contributes principally to the termination of feeding bouts in caterpillars, while nutrient flow may affect both the initiation and termination of feeding.
Trade‐off between flight and reproduction in the African armyworm moth, Spodoptera exempta
Authors: GUNN A. , GATEHOUSE A. G. , WOODROW K. P. 
Published: March 2008

ABSTRACT. The existence of a trade‐off between flight and reproduction in the migratory noctuid, Spodoptera exempta (Wlk.), was examined in experiments in which female moths were flown on flight balances and then provided with distilled water or sucrose solution. For individuals flight‐tested from the night of eclosion (night 0) through night 1 and fed only distilled water, there was a linear, negative relationship between weight‐related fecundity and flight duration. When flight was recorded through night 2, a curvilinear relationship was obtained suggesting that highly active moths suffer a smaller decrease in fecundity than predicted from its rate of decline with increasing flight duration in less persistent fliers. The hypothesis that this reflects an energetically expensive, initial phase of each flight, followed by a less costly, cruising phase is examined. Fecundity was independent of flight duration in females provided with sucrose after flight but was related to moth weight, as it was in all unflown moths. Effects of flight and feeding on longevity and mating frequency are also reported.There is a clear trade‐off between flight and fecundity in S.exempta which is only evident in moths denied access to a source of carbohydrate after flight. The results indicate the importance of nectar sources in the field in allowing restoration of lipid reserves depleted during migratory flight. An important implication of this conclusion is that lipid is the resource limiting to fecundity in this species and not protein as is generally supposed for leaf‐feeding insects. This might be expected in highly active species as lipid is the resource for which the energetically expensive functions of flight and reproduction must compete.
The distribution and relative potency of diuretic peptides in the house cricket, Acheta domesticus
Authors: COAST G. M. , WHEELER C. H. 
Published: March 2008

ABSTRACT Dose‐response curves are presented for the diuretic activity in aqueous extracts of brain, retrocerebral complex, and ventral nerve cord ganglia from Acheta domesticus. Diuretic activity is highest in extracts of brain and corpora cardiaca. In comparison with such extracts, those of the suboesophageal ganglia and thoracic ganglia I‐III produce truncated responses, whilst abdominal ganglia 1–4 show evidence of an inhibition of the diuretic response at high doses. ED50 values, obtained from Hill plots, are similar for extracts of brain, corpora cardiaca, corpora allata, and abdominal ganglia, but are 3–4 times higher for extracts of suboesophageal and thoracic ganglia.Separation of aqueous extracts of corpora cardiaca by reversed‐phase HPLC yields a number of fractions which stimulate fluid secretion in isolated tubules. Diuretic activity in these fractions is destroyed by treatment with Pronase E, and on this basis is identified as peptidic. In general, diuretic activity is found in the same RP‐HPLC fractions prepared from aqueous extracts of brain, suboesophageal ganglia, thoracic ganglia I‐III, and abdominal ganglia 1–4.
Periodic muscular activity and its possible functions in pupae of Tenebrio molitor
Authors: TARTES URMAS , KUUSIK AARE 
Published: March 2008

Abstract. During pupal development, Tenebrio molitor L. show regular periods of rhythmic muscular contractions and associated body movements. These periods of activity last 2.5‐5.8 min and are more frequent in newly ecdysed pupae (c. 3h‐1). They become less frequent (c. 1.5 h‐1) when the basal metabolism reaches its lowest level. In the pharate adult stage the clear pattern of muscular activity disappears.Muscular activity is temperature‐dependent and is commonly absent below 20d̀C. Muscular activity did not disturb the cyclic output of CO2, which is characteristic of metamorphosis. The heart shows characteristic periods (1–3 min) of activity during pupal development. The frequency of these heart pulsation periods depends on metabolic rate. Heart pumping was correlated mostly with muscular contractions. Therefore we suggest that the main physiological function of muscular activity is to support circulation.
Feeding behaviour of female Aedes aegypti: effects of diet temperature, bicarbonate and feeding technique on the response to ATP
Authors: MOSKALYK L. A. , FRIEND W. G. 
Published: March 2008

Abstract. The effects of variation in diet temperature, mouthpart deployment and the addition of bicarbonate to a saline‐ATP diet were investigated for their effects on amount ingested and diet destination in female Aedes aegypti (L.). Mouthpart deployment was achieved by having the insects feed through a membrane, or from a free‐liquid surface with mouthparts intact, or with the fascicle separated from the labial groove.Under the ‘feeding through membrane’ protocol, a 6‐fold increase in the percentage of Aedes feeding on ATP‐diets was recorded at 37d̀C compared with 21d̀C. Bicarbonate (9.5 or 19 mM) induced a 3‐fold increase in numbers feeding at both 21d̀C and 37d̀C. Neither diet temperature nor bicarbonate content appeared to affect meal size. The pH of all diets was adjusted to 7.0. Diet was directed primarily to the midgut for all diets tested under this regimen, with the exception of the saline‐ATP‐19 mM NaHC03 at 37d̀C which caused the diet to be directed primarily to the crop.Under the ‘feeding without membrane through feeding tube’ protocol, females showed little control over diet destination. Female Aedes aegypti exhibited no strong response to ATP when the mouthparts were immersed in 21d̀C diets in feeding tubes and few of these insects ingested large meals. The addition of bicarbonate to the ATP diets did not enhance feeding under these test conditions.
Fungal hyphae as a source of nutrients for the leaf‐cutting ant Atta sexdens
Authors: BASS M. , CHERRETT J. M. 
Published: March 2008

Abstract. The mutualistic fungus of leaf‐cutting ants produces both ordinary hyphae and specialized ant rewards: the staphylae. Workers of Atta sexdens (L.) lived longer on diets which included nutritive staphylae than on those which provided only hyphae. However, hyphae were a better diet than sucrose solution or water alone. Small workers lived longer than large workers when receiving fungus garden, whether or not staphylae were available, probably because they are specialized to care for the garden and can exploit it. Large workers lived longer than small ones when only water was available. This may be a consequence of scale, larger workers containing proportionately more nutritional reserves in their bodies.When starved workers were exposed to fungus for 3h, they gained weight. This weight gain represented the amount of food ingested during the test period. Workers gained 7.3 times more weight on natural fungus garden bearing staphylae than on garden with only hyphae. They gained only 1.5 times as much weight when the fungus was artificially cultured on agar. The results suggested that workers found hyphae attractive, but difficult to obtain in natural fungus gardens.Material from hyphae and staphylae stained with a fluorescent dye was detected in worker crop contents using fluorescence microscopy. The crop contents of workers fed on staphylae fluoresced 1.14 times more than those of workers fed on hyphae.Hyphae may provide a small source of food for workers, and the fungus as a whole may provide up to 9.0% of the respiratory energy requirements of workers, the remainder presumably being provided by plant sap.
Changes in learning ability and mechanism during development of grasshopper nymphs, Melanoplus bivittatus
Authors: HOLLIDAY J. L. , HOLLIDAY N. J. 
Published: March 2008

Abstract. In an experimental arena, Melanoplus bivittatus (Say) (Orthoptera: Acrididae) nymphs of four stadia were observed to determine whether they learn to associate food with positional or light‐related cues. Nymphs were observed for 4 h in the arena containing one yellow box and one green box, then they were trained by placing food in the green box overnight. Following training, the responses of nymphs to green and yellow boxes were observed for a second 4 h period.Before training, nymphs of all stadia visited the yellow box more frequently than the green box. Training did not affect the behaviour of second‐stadium nymphs, but training increased the relative frequency of visits to the green box by third, fourth and fifth instars. Effects of training on duration of visits to boxes were not evident. Investigations of the mechanism of learning showed that positional cues were used by third‐stadium nymphs, but that fourth and fifth instars responded to light‐related cues. The progression from no learning in second instars, through use of positional cues by third instars, to use of light‐related cues by fourth and fifth instars is probably associated with the greater mobility, greater food consumption, and more varied diet of older nymphs.
Tarsal contact chemoreceptor response to glucosinolates and cardenolides mediating oviposition in Pieris rape
Authors: STÄDLER ERICH , RENWICK J. A. A. , RADKE CELIA D. , SACHDEV‐GUPTA KUSUM 
Published: March 2008

Abstract. Water‐soluble extracts of a host crucifer (Brassica oleracea L.) and non‐host crucifer (Erysimum cheiranthoides L.) and isolated pure cardenolides and glucosinolates were tested on Pieris rapae L. (Lepidoptera: Pieridae) butterflies in oviposition assays and by electrophysiological recordings from the contact‐chemoreceptor sensilla of the prothoracic tarsi.Ten different glucosinolates stimulated oviposition to varying degree when put on non‐host plant leaves. The most active compounds were glucobrassiein and gluconasturtiin (methylindole and phenylethyl aglycone), whereas glucocapparin, sinalbin. glucotropaeolin, sinigrin and glucoalyssinin had intermediate activity. Glucocheirolin, glucoerucin and glucoiberin (sulphur‐containing aglycone) were significantly less active.Of eight cardenolides applied to host‐plant leaves (100 μg each), four glycosides deterred oviposition strongly (erysimoside, erychroside, cymarin and K‐strophanthin‐β). Erycordin, helveticoside, digitoxin and strophanthidin had little or no deterrent activity.Sensilla located laterally on the prothoracic tarsi of female butterflies contained one receptor cell sensitive to sucrose. None of the tested extracts or pure compounds stimulated any cell in these sensilla. In contrast, the cells in the medial sensilla showed little or no sensitivity to sucrose. One cell was found to be sensitive to cardenolide glycosides. The threshold for one of the most active compounds, erychroside, was about 0.1 μg/ml (1.5 times 10‐7 M). Two receptor cells, characterized by spikes of differing amplitude, were sensitive to glucosinolates. One of these, with larger amplitude spikes, seemed to be the same as the cell sensitive to cardenolides. The threshold for the most active glucosinolates, glucobrassicin and gluconasturtiin was estimated to be below 0.1 mg/ml (2 times 10‐4 M). The neural activity of both classes of compounds, cardenolides and glucosinolates, was significantly correlated with their behavioural activity as deterrents or stimulants.