bluuebunny/crossref_metadata_2025 huggingface dataset:
Respiration in the sexuals of the ant Lasius flavus
Authors: NIELSEN MOGENS GISSEL , SKYBERG NILS , PEAKIN GREG
Published: March 2008

ABSTRACT. Gynes and males of Lasius flavus Fab. were taken from the nest as they eclosed, and at intervals thereafter until the mating flight, and their respiration was measured. After the mating flight respiration was measured in gynes at various stages of colony foundation. Respiration in gynes rose rapidly to a peak as they began to accumulate food reserves for colony foundation. Subsequently, the respiratory rate declined and remained at a low level until the mating flight and during the claustral phase of colony foundation. Once the colony was well established and the queen actively laying, the respiratory rate returned to that at the beginning of maturation. Males showed smaller changes in their respiratory rates, which were generally higher than those of the gynes. The variation in respiration in males seemed to be due to increasing restlessness as the time of the mating flight approached.
Relationship between rocking behaviour and copulation termination in Lygaeus equestris
Authors: SILLÉN‐TULLBERG BIRGITTA
Published: March 2008

ABSTRACT. During copulation (end‐to‐end position) females of Lygaeus equestris L. (Heteroptera, Lygaeidae) show a sideways, stereotyped movement called ‘rocking’, the function of which has been unclear. Since copulation interferes with other behaviours, females exposed to excess copulation have a lowered fitness, and would benefit from being able to influence the termination of copulation. It is here argued that they do so by rocking. First, it is shown that the variance of in copula duration was lower in rocking than non‐rocking pairs, presumably because long copulations are avoided. Second, the frequency of rocking individuals and the intensity of the behaviour are higher in gravid than in non‐gravid females. Third, defecation is hindered by copulation, which could be one reason for young, not yet reproductive females wanting to terminate copulation. Last, rocking individuals defecate sooner and lay eggs sooner than non‐rocking ones. The mechanism by which rocking might effect termination of copulation is discussed.
Mosquito‐mediated attraction of female mosquitoes to a host
Authors: AHMADI ABBAS , McCLELLAND G. A. H.
Published: March 2008

ABSTRACT. Female mosquitoes seeking blood respond primarily to kairomones emitted by potential hosts. We now confirm, in the laboratory, field evidence showing that the presence of other female mosquitoes at the host significantly enhances the host‐seeking response. Olfactometry strongly suggests that a chemical of mosquito origin is responsible. The adaptive value of this behaviour is discussed.
A pulsed cloud of sex pheromone elicits upwind flight in male moths
Authors: BAKER T. C. , WILLIS M. A. , HAYNES K. F. , PHELAN P. L.
Published: March 2008

ABSTRACT. Male oriental fruit moths do not fly upwind in a continuous uniform cloud of pheromone, but readily do so when the cloud is pulsed at 1 or 0.5/s or when a plume from a point source of pheromone is placed within the continuous cloud. It is suggested that males of moth species that require such fluctuating pheromone stimulation for upwind flight will normally receive it from a filamentous, point‐source‐produced plume. However, we hypothesize that upwind progress may cease close to the source due to excessively high emission rates or inappropriate blend ratios, when fluctuating sensory output becomes attenuated, despite higher actual molecular concentration fluctuations.
Effect of ATP analogues on the gorging response of Aedes aegypti
Authors: GALUN RACHEL , KOONTZ LOUIS C. , GWADZ ROBERT W. , RIBEIRO JOSE M. C.
Published: March 2008

ABSTRACT. The ATP analogues adenylylimidodiphosphate and adenylylmethylenediphosphate are 3–5‐fold more effective than ATP as gorging stimulants for Aedes aegypti. This increased potency is not due to the fact that the two analogues are not hydrolysed by the mosquito salivary apyrase, but most likely to their greater affinity to the mosquito gustatory receptor protein. The analogues 2'd ATP and 3'd ATP are about half as potent as ATP, while 2′,3′‐dideoxyadenosine triphosphate is 10‐fold more potent than ATP in evoking the gorging response. It is proposed that removal of both hydroxyl groups eliminates binding of the stimulant at the ribose moiety, thus allowing the molecule greater freedom to rotate and bind more effectively to its two other binding sites at the amino group on the purine and at the terminal phosphate. Our data demonstrate that ATP activates the gorging response of Ae.aegypti merely by binding to its receptor protein and is not required as an exogenous source of energy. Gorging response to ATP is competitively inhibited by novobiocin.
Swarming behaviour of the mosquito Culex pipiens quinquefasciatus: a quantitative analysis
Authors: GIBSON GABRIELLA
Published: March 2008

ABSTRACT. Analysis of video recordings of Culex pipiens quinquefasciatus Say swarms showed that the overall swarming patterns of males and virgin females are similar, even though the short‐term characteristics of their flight, such as speed and turning angle, differ. This suggests they have the same response to the visual cue of the swarm ‘marker’. The swarming pattern of an individual consists of elliptical loops which, in the short‐term, define an area smaller than the swarm as a whole. The foci of these ellipses drift gradually with respect to the marker; individuals do not seem to have preferred positions within the swarm, but drift at random. Male mosquitoes identify and locate females by the sound of their wing‐beats. Diffuse sound at the wing‐beat frequency of female C.p. quinquefasciatus (500–600 Hz) caused males within the swarm to slow down significantly. Their turning behaviour remained unchanged, so the ellipses decreased in size. The swarm as a whole collapsed into a smaller volume, centred over the marker. Apparently, the response of males to sound consists of at least two parts: initially they alter their flight speed, and then alter their turning behaviour once they have located the source of the sound.
Responsiveness to light of the circadian clock controlling eclosion in the blowfly, Lucilia cuprina
Authors: SMITH PETER H.
Published: March 2008

ABSTRACT. Eclosion in Lucilia cuprina (Wiedemann) occurs near dawn. The rhythm of eclosion persists in both darkness and constant light of high intensity (490μW cm‐2) with a period close to 24h. The sensitivity to light of the circadian clock controlling eclosion varies greatly according to the stage of the life cycle. During larval life the free running rhythm in darkness can be phase shifted by light pulses of 100μW cm‐2 intensity, with the transition from a Type 1 phase response curve to a Type 0, occurring with pulses of between 1 and 8h. Extending the last light period of LD to 24 h followed by constant darkness resets the phase of the rhythm by 12h, a transition from constant light to constant darkness initiates rhythmicity in flies made arrhythmic by being reared from eggs collected from adults maintained in constant light. After pupariation, the rhythm is relatively insensitive to light. Rhythmicity is sometimes induced by a transition from constant light to constant darkness, but the phase of the rhythm is not shifted by extending the last light period of LD before entering constant darkness. Repeated LD cycles applied after pupariation initiate and entrain the rhythm.
Oxygen consumption of flying locusts
Authors: ARMSTRONG G. , MORDUE W.
Published: March 2008

ABSTRACT. Desert locusts (Schistocerca gregaria Forskal.) were flown into an airstream from a wind tunnel while tethered to a balance. Rate of oxygen consumption and lift were recorded. The mean rate of oxygen consumption of male locusts in level flight at airspeeds between 2.5 and 3m/s was found to be 12.6ml/g/h.
The selection for early and late pupariation in the flesh‐fly, Sarcophaga argyrostoma, and its effect on the incidence of pupal diapause
Authors: BRADLEY HELEN K. , SAUNDERS D. S.
Published: March 2008

ABSTRACT. Artificial selection from the first and last larvae of Sarcophaga argyrostoma (Robineau‐Desvoidy) to form puparia gives rise to two strains, ‘fast’ (F) and ‘slow’ (S), ‘fast’ pupariating about 3 days earlier than ‘slow’ in continuous light, 25°C. The two strains differ only in the time from larval wandering to pupariation; other aspects of development are identical. In light‐dark cycles (1°C) the distributions of pupariation times in ‘fast’ are unimodal and nearly normal, whereas those for ‘slow’ are multimodal and with a marked skew, especially in short daylengths. Pupariation times in ‘fast’×‘slow’ hybrids, an F2 generation, and a backcross [(F×S)×S] are intermediate between ‘fast’ and ‘slow’ but incline towards ‘fast’. It is concluded that control of pupariation time is polygenic, and that ‘slow’ contain considerable residual variation. When compared with the unselected stock, ‘fast’ and ‘slow’ both produce a reduced incidence of pupal diapause in short daylengths, and ‘fast’ show a shorter critical daylength. These effects are interpreted in terms of a modified version of Gibbs' (1975) photoperiodic ‘counter’ hypothesis.
Azadirachtin: its effect on gut motility, growth and moulting in Locusta
Authors: (LUNTZ) A. J. MORDUE , COTTEE P. K. , EVANS K. A.
Published: March 2008

ABSTRACT. The biological effect of azadirachtin on fifth instar nymphs of Locusta migratoria migratorioides (R & F) have been studied in detail. Azadirachtin injection at the beginning of the instar results in a dose‐dependent range of developmental aberrations. Low concentrations (c. 1.7/μg/g body weight) result in adults with curled wing tips and reduced longevity; higher concentrations (c. 2.9μg/g) result in death during the imaginal moult; doses of c. 6.5μg/g cause death immediately prior to the moult; and doses of c. 7.3μg/g induce a greatly extended instar. Such doses are related to a proportionately slower growth rate of the insect and a significantly reduced food intake, as assessed by wet weight and faeces production. Doses of 80μg/g result in death within 24 h. Experiments in vivo and in vitro demonstrate a significant reduction with azadirachtin treatment in the rate of passage of food through the gut, and in gut motility. The significance of this direct effect on gut motility is discussed in relation to the mode of action of azadirachtin on growth and moulting.
How do bees choose flight direction while foraging?
Authors: SCHMID‐HEMPEL PAUL
Published: March 2008

ABSTRACT. Various authors have reported that nectar‐collecting bees usually maintain an overall degree of directionality in their successive foraging flights. I here ask what kind of cues honeybees (Apis mellifera) use to decide on departure direction from one inflorescence to the next. In a horizontally placed flower array, individual workers were experimentally rotated while imbibing sugar solution from an artificial flower mounted on a turntable. Rotation itself did not affect the subsequent departure direction. However, rotating the bees by 180° resulted in choices that were rotated by the same amount, as compared to the control treatment (i.e. no rotation). I suggest that flight directionality is determined in bees from the spatial orientation of their body before departure (e.g. by moving to the nearest flower they face).
Compensation by locusts for changes in dietary nutrients: behavioural mechanisms
Authors: SIMPSON S. J. , ABISGOLD J. D.
Published: March 2008

ABSTRACT. The detailed behavioural mechanisms underlying an instance of compensation for changes in dietary nutrients are described for the first time in an insect. Nymphs of Locusta migratoria L. were given one of four artificial diets on the third day of the fifth instar, and their feeding patterns recorded in detail for 12 h. The diets represented combinations of two protein and two digestible carbohydrate levels (28% and 14% dry weight) presented in an otherwise complete nutrient mix. At the nutrient levels used, locusts regulated their intake of food with respect to protein but not digestible carbohydrate in the diet. They ate more of the lower protein diets by eating the same sized meals more frequently than insects fed on the higher protein diets. Compensation was not complete over the 12 h observation period: insects on the lower‐protein diets ingested and absorbed 72% as much nitrogen as those insects fed on the higher‐protein diets. Possible physiological mechanisms underlying the behavioural mechanisms are discussed.
The effect of hybridization on the periodicity of sex pheromone release of Euxoa species (Lepidoptera: Noctuidae)
Authors: TEAL P. E. A.
Published: March 2008

ABSTRACT. The periodicities of sex pheromone release by reciprocal F1 hybrid females obtained from laboratory matings between Euxoa declarata (Walker) and E. rockburnei Hardwick were found to be dependent upon the parental cross. The period of sex pheromone release by females from the E. declarata (female) ×E. rockburnei (male) cross paralleled that of the maternal parent species, E. declarata. However, female hybrid E. rockburnei (female) ×E. declarata (male) had a prolonged calling period which intersected the pheromone release periods of both parental species and peaked later than that of E. declarata. These results indicate that the circadian periodicity of calling in these species is controlled by autosomal genes and a matroklinal inheritance factor.
The time course of dark adaptation in the bee: a phototactic and electrophysiological investigation
Authors: KINDERMANN UTE , HERTEL HORST
Published: March 2008

ABSTRACT. The time course of dark adaptation in Apis melifera L. was investigated by analyses of phototactic behaviour and electroretinogram (ERG). The behavioural results give a function for dark adaptation showing that in the dark after strong light adaptation the sensitivity increases exponentially with a time constant of 3 min. The sensitivity changes c. 2.4 log units during the time span of 5–720 s. The electrophysiological results indicate a smaller change in sensitivity at the level of the photoreceptors. Within a time span between 20 and 720 s the sensitivity increases during dark adaptation by a factor of 4.3 on a linear scale.
The feeding behaviour of caterpillars (Manduca sexta) on tobacco and on artificial diet
Authors: REYNOLDS S. E. , YEOMANS M. R. , TIMMINS W. A.
Published: March 2008

ABSTRACT. Feeding behaviour of fifth instar tobacco hornworm caterpillars, Manduca sexta (Johansen) (Lepidoptera; Sphingidae), eating tobacco or artificial diet, is quantitatively described. The insects grow at the same rate on both foods. There is no daily rhythm of feeding behaviour. For most insects, feeding on either food occurs in bouts with the lengths of interfeed gaps and of feeding bouts appearing to be distributed randomly. However, in many insects there is a strong correlation between the length of a feeding period and that of the preceding non‐feeding period.

The proportion of time spent feeding on tobacco is much greater than on artificial diet. On tobacco, feeding periods are separated by shorter interfeed gaps than on the artificial diet, while the rate of bout initiation is similar on either food.

On both tobacco and artificial diet, the proportion of time spent feeding increases as the fifth stadium proceeds. This is due to both longer feeding bouts and shorter gaps. The rate of food acquisition within bouts does not change during the stadium.
Modification of the courtship song by visual stimuli in the grasshopper Gomphocerus rufus (Acrididae)
Authors: RIEDE KLAUS
Published: March 2008

ABSTRACT. Males of Gomphocerus rufus L. perform a courtship song consisting of repetitive units, each of which is composed of three subunits (S1, S2, S3). S1 is characterized mainly by slow and fast head rolling; S2 and S3 are distinguished by different types of leg‐stridulation. These movements and the associated sounds were recorded during presentation of visual stimuli, either linear displacement of a living female or optomotor stimuli generated by a striped drum. Females moved artificially through the binocular visual field of a courting male with a velocity of 1 cm/s or more are mounted by the male from any subunit S1, S2 or S3, although under natural conditions mounting occurs only from S2. Thus above a critical velocity the courtship programme can be modified. Rotation of a striped drum about the yaw axis of the male during the slow S1 induces asymmetrical leg position, following movements of the head, and prolongation of S1. During S2 the male is especially sensitive to optomotor stimuli and responds with marked changes in body position. In S3 the intensity of the song is reduced, and its duration shortened. Fast drum movements interrupt the courtship programme. Rotation of the drum about the roll axis elicits optomotor head turning that interferes with the head rolling of S1. The fast phase of S1 and the frequency of head‐rolling during S1 cannot be modified by optomotor stimulation. The results can be interpreted by assuming certain interactions between three central nervous elements: a calling‐song generator, a head‐rolling generator, and an optomotor centre.
A comparative study on the isolation of adipokinetic and hypertrehalosaemic factors from insect corpora cardiaca
Authors: GÄDE GERD , SCHEID MARIANNE
Published: March 2008

ABSTRACT. Extracts of corpora cardiaca from two cockroaches, Nauphoeta cinerea Olivier and Leucophaea maderae F., from a cricket, Gryllus bimaculatus De Geer, from the Colorado potato beetle, Leptinotarsa decemlineata Say, and from the sphinx moth, Sphinx ligustri L. were assayed for adipokinetic and hypertrehalosaemic activity, in acceptor locusts (Locusta migratoria L.) and cockroaches (Periplaneta americana L.) respectively. Both bioassays give positive results with all corpus cardiacum material tested except that from the sphinx moth; in this insect haemolymph lipid concentrations (but not those of the total carbohydrate) are, however, increased after injection of an extract of corpora cardiaca from the same species. A similar result is obtained when specimens of G. bimaculatus are injected with an extract of corpora cardiaca from G. bimaculatus. Biological activities of corpus cardiacum extracts from all species investigated can be resolved on reversed‐phase high‐performance liquid chromatography. Gland extracts from the two cockroach species each show a single absorbance peak which has hypertrehalosaemic activity, but with a (common) retention time distinct from all previously described arthropod neuropeptides. The corpora cardiaca of G. bimaculatus contain also a novel adipokinetic factor with a retention time distinct from previously characterized arthropod hormones, as well as from the new cockroach factor described in this study. The two hypertrehalosaemic factors from the corpora cardiaca of the potato beetle coelute with the hypertrehalosaemic hormones I and II of the American cockroach. The active (adipokinetic) compound from glands of S. ligustri appears to coelute with locust adipokinetic hormone I.
Fine structure, function and distribution of antennal sensilla in the saw‐toothed grain beetle, Oryzaephilus surinamensis
Authors: WHITE PETER R. , LUKE BARBARA M.
Published: March 2008

ABSTRACT. Antennae of the saw‐toothed grain beetle (Oryzaephilus surinamensis L.) (Coleoptera: Silvanidae) were examined using scanning and transmission electron microscopy to determine the fine structure and distribution of sensilla. Seven morphologically different sensilla types are distinguished. Mechanoreceptor hairs account for over 68% of all sensilla. Mechanoreceptors are also found in conjunction with contact chemo‐receptors; this dual function is demonstrated by electrophysiological recordings. Three different types of olfactory chemoreceptor are found, accounting for 26% of all sensilla, plus two sensilla types with possible hygro/thermo‐receptor functions. Counts show the numbers of chemo‐receptors to be small, though this many simply reflect the small size of these beetles.
Patterns of intermittent ventilation and responses to perfusing gas mixtures in quiescent Blaberus craniifer
Authors: EDWARDS H. A. , MILLER P. L.
Published: March 2008

ABSTRACT. Patterns of intermittent ventilation were recorded by means of long electromyogram wires from quiescent Blaberus craniifer (Burmeister) buried in vermiculite. While buried, cockroaches were subjected to perfusion with various mixtures of CO2 in air and of oxygen in nitrogen. Quiescent cockroaches in air ventilated for mean periods of 138 s in cycles of 720s duration, but much variability occurred within and between cockroaches. Mild hypercapnia or hypoxia shortened the overall cycle time while more severe treatment caused the cycle to be replaced by continual pumping. Intermittent ventilation persisted in decapitated insects but the threshold of the response to hypoxia or hypercapnia was elevated. Prevailing gas tensions normally determine the frequency and duration of each phase.
Post‐feed buzzing in the tsetse, Glossina morsitans morsitans, is an endothermic mechanism
Authors: HOWE M. A. , LEHANE M. J.
Published: March 2008

ABSTRACT. Post‐feed buzzing in Glossina morsitans morsitans Westw. causes a rise in thoracic temperature relative to the length of the buzz. As lift is proportional to the square of wing‐beat frequency, which increases with temperature up to 32°C, buzzing results in an increase in the lift which the fly can produce. Heat generated by buzzing, in combination with the heat received from the host at the time of feeding, may well allow the fly to maximize lift generated in the immediate post‐feeding period. Buzzing flies excrete excess water from the meal more rapidly than non‐buzzing flies. It is argued that this is due to a rise in abdominal temperature. Maximized lift in the immediate post‐feeding period and the rapid elimination of water from the very large blood meals taken by these flies may be expected to have strong selective advantages for the flies.
Vibration and sound communication in solitary bees and wasps
Authors: LARSEN OLE NÆSBYE , GLEFFE GEORG , TENGÖ JAN
Published: March 2008

ABSTRACT. Females of solitary bees (Colletes cunicularius L.) and of digger wasps (Bembix rostrata L.) produce buzzing sounds and are known to secrete volatile odours when digging their way from the subterranean nests to the soil surface. The odours allow patrolling males to determine the approximate position of the digging virgin female. The buzzes are measured as substrate‐borne sound (soil buzz vibrations) and as air‐borne sound (soil buzz sounds). Play‐back experiments suggest that the soil buzzes are used by the males as additional cues for localization. Faint buzz sounds are emitted regularly by the male during genital contact in copulation. They may serve to change the receptivity of the female. Intense and broadband buzz sounds are produced by bees of either sex, if restrained from moving, perhaps serving to deter predators.
Evidence for a female sex pheromone in the brassica pod midge Dasineura brassicae
Authors: WILLIAMS INGRID H. , MARTIN A. P.
Published: March 2008

ABSTRACT. The responses of Dasineura brassicae Winn. (Diptera, Cecidomyiidae) to odours from both male and female midges and from their host (Brassica napus) and non‐host (Vicia faba) plants were studied using a Y‐tube olfactometer. Female but not male D. brassicae are attracted to crushed B. napus leaves but not to those of V. faba. Males are attracted to live virgin females, to crushed virgin and mated females and to hexane washes of females, suggesting that the female produces a sex pheromone that attracts males. Males were also attracted to hexane washes of female ovipositors, but not to washes of the bodies of females without ovipositors, suggesting that the ovipositor is the site of pheromone release or production. Males were not attracted to live mated females or to other live or crushed males and mated females were not attracted to other mated females.
Influence of sexual organs on corpora allata biosynthetic activity in Locusta migratoria
Authors: COUILLAUD FRANCK
Published: March 2008

ABSTRACT. Using an in vitro radiochemical assay, juvenile hormone (JH) biosynthesis by corpora allata was screened during the first 2 weeks of adult maturation in both male and female migratory locusts, Locusta migratoria migratorioides (R. & F.). The patterns of change of glandular activities in the sexes were different, but the overall rates of JH production were similar. Testisectomy did not appear to affect corpus allatum activity, male sexual behaviour, or yellow coloration. Removal of the testes together with the seminal vesicle and the accessory glands resulted in a disturbance of the pattern of JH biosynthesis, but had no effect on sexual behaviour or coloration. These observations are discussed in relation to available evidence on JH‐mediated sexual events in the adult.
Effects of colours and synthetic odours on the attraction of Glossina pallidipes and G. morsitans morsitans to traps and screens
Authors: GREEN C. H.
Published: March 2008

ABSTRACT. Glossina morsitans morsitans Westw. and G. pallidipes Aust. flying around and landing on coloured screens and traps were sampled using electrocuting nets. External colour affected both attractiveness and efficiency of traps, such that yellow and green traps were unattractive and inefficient; black and red, attractive and inefficient; white, moderately attractive, and very efficient; and blue traps, attractive and efficient. The order of attractiveness of coloured screens was similar to that for traps. Landing responses were generally strongest on black surfaces, and weakest on white, but the results for blue were variable. Carbon dioxide and acetone odours improved trap catches and also eliminated most catch differences between traps differently coloured on their outer surfaces. The relative performances of traps coloured differently on inside surfaces only were not affected significantly by these odours, and in all cases black or red target areas inside the trap were required for optimum trap performance. When acetone and 1‐octen‐3‐ol odours were used, catches were improved but the relative performance of differently coloured traps and screens was not changed. There were no obvious species differences in colour responses although numbers of G. morsitans were too low for statistical comparisons.
Filtering mechanism of the honey bee proventriculus
Authors: PENG YING‐SHIN , MARSTON JERRY M.
Published: March 2008

ABSTRACT.The fine structure and function of a honey bee's (Apis melliferaLinn.) proventriculus were studied by scanning electron microscopy and video‐recording. Our observations revealed that the proventriculus is used to engulf pollen and other particles which contaminate the nectar carried into the crop. The four lips are closed and opened, pulled backwards and straightened by the external circular muscles and internal longitudinal muscles. Combs of filiform‐hairs (70 μm in length) located on the margins of the lips ‘catch’ and filter particles from the fluid. By repeated filtering, opening and closing actions of the hairs and lips, particles are filtered and collected in pouches between the ventricular folds to form boluses and are eventually passed into the midgut. In the present experiment, particle sizes ranging from 0.5 to 100 μm in diameter, including dandelion pollen (Taraxacum officinaleWeb.), Torula yeast (Candida utilisLodder et Kreger‐Van Rij), bee disease spores ofNosema apisZander andBacillus larvaeWhite, and man‐made particles can be filtered by the hairs. Small particles (0.23 μm in diameter) filter through the hair and return back to the fluid. Large particles (100–200 μm in diameter) are caught between the stylets of the mouthparts and are not ingested. These observations suggest that the particle size plays an important role in determining what can be taken by the mouthparts and the proventriculus and what can later be utilized as a food source by the bee. The role of the proventriculus in disease transmission is also discussed.
De‐alation, flight muscle histolysis, and oocyte development in the striped ground cricket, Allonemobius fasciatus
Authors: TANAKA SEIJI
Published: March 2008

ABSTRACT. Removal of hindwings from long‐winged females of the striped ground cricket, Allonemobius fasciatus, DeGeer (Gryllidae), induces flight muscle histolysis and oocyte development. Such females develop oocytes as rapidly as do short‐winged forms, while intact long‐winged females retain their flight muscles and develop few oocytes.

Flight muscle histolysis occurs in starved long‐winged females when they are de‐alated. However, such females fail to mature oocytes. Implantation of corpora allata (CA) into long‐winged females results in flight muscle histolysis as well as oocyte maturation even if their hindwings remain intact, indicating that flight muscle histolysis can take place without de‐alation. It is likely that the CA are responsible for both flight muscle histolysis and oocyte development, and that CA activity is enhanced by de‐alation.
Ultrastructure of the galeal sensory complex in adults of the Colorado potato beetle, Leptinotarsa decemlineata
Authors: SEN A. , MITCHELL B. K.
Published: March 2008

ABSTRACT. The structure of galeal sensilla of the Colorado potato beetle, Leptinotarsa decemlineata Say (Coleoptera: Chrysomelidae), is described using electron microscopical methods. Previous electro‐physiological studies indicate that these sensilla respond to amino acids, sucrose and plant saps. One physiological type is particularly sensitive to L‐alanine and gamma amino butyric acid (GABA).

Three morphologically different types of sensilla occur on the galeal tip. The more numerous apical pegs are not distinguishable from one another on the basis of external structure, although they differ physiologically. Five sensory cells are associated with most apical pegs. One apical peg, the α‐sensillum, contains only four cells. All apical pegs have one cell with a tubular body. The remaining cells have unbranched dendrites and are associated with a single apical pore.

Apical hairs differ from the apical pegs by having double innervation. Within the hair shaft, a dendritic sheath is lacking and the sensillar sinus extends to the base of the hair. The function of this hair type is not known.

Numerous mechanosensory hairs which surround the other sensilla are singly innervated and contain a tubular body at the level of the outer dendritic segments.
Diel rhythmicity of prey‐search activity and its predominance over starvation in the lady beetle, Coccinella septempunctata bruckii
Authors: NAKAMUTA KIYOSHI
Published: March 2008

ABSTRACT. The locomotor activity of the lady beetle, Coccinella septempunctata bruckii Mulsant (Coleoptera: Coccinellidae), was recorded during food deprivation in LD 16:8 h and continuous light. Activity was relatively low immediately after the lady beetle was fed to satiation but increased from 4 to 24 h later. It thereafter gradually decreased to a low level when the food was withheld for several days. Over a period of 10 days of starvation the beetles showed a high level of activity throughout the photophase and a low level during the scotophase in LD 16:8 h. In continuous light this rhythmic pattern persisted, with a free‐running period of c. 22 h, significantly shorter than 24 h. The results suggest that the endogenous circadian timing predominates over ‘hunger’ as a determinant of search activity. The lady beetle accepted and consumed aphid prey presented at night, but the number of prey consumed was significantly lower than in the light. This suggests that, during the dark, activity related to prey‐searching is suppressed, though lady beetles are able to accept and consume prey even at night.
Naturally occurring arrhythmicity in eclosion and activity in Lucilia cuprina: its genetic basis
Authors: SMITH PETER H.
Published: March 2008

ABSTRACT. Colonies of wild‐type Lucilia cuprina (Wiedemann) (Diptera: Calliphoridae) in our laboratory differed greatly in the degree of rhythmicity of their eclosion when exposed to light/dark cycles, constant darkness or constant light. Among colonies reared in the laboratory for thirty‐four to eighty‐eight generations and others for more than 360 generations, some were consistently rhythmic, others weakly rhythmic and others arrhythmic.

One colony with arrhythmic eclosion was studied further. Arrhythmicity of eclosion in the colony was found to result from homozygosis of a recessive allele (ary) on chromosome 5. Adults from this colony were arrhythmic in spontaneous flight activity under constant darkness though rhythmic under light/dark cycles.
Simultaneous monitoring of flight and oviposition of individual velvetbean caterpillar moths (by Wales, Barfield & Leppla, 1985): a critique
Authors: GATEHOUSE A. G. , WOODROW K. P.
Published: March 2008

ABSTRACT. Flight durations of tethered female Anticarsia gemmatalis moths recorded in the laboratory were interpreted by Wales et al. as indicating a capacity for significant inter‐reproductive displacements in the field. Indications that their data may not support this conclusion are discussed and evidence is presented that, in tethered Spodoptera exempta, prolonged flights starting early in the night represent migratory behaviour while those of similar durations starting after midnight do not.
Scototaxis and shape discrimination in the female cricket Acheta domesticus in an arena and on a compensatory treadmill
Authors: ATKINS GORDON , ATKINS STEVEN , SCHOUN DAN , STOUT JOHN F.
Published: March 2008

ABSTRACT. The scototactic responses of adult female Acheta domesticus L. were tested toward various shaped targets in an orientation arena and on a compensatory treadmill. In an arena, crickets oriented toward dark targets (positive scototaxis) if they had horizontal visual angles ≥30d̀, and if the vertical dimensions of the target was ≤ its horizontal dimension. Unattractive targets did not result in negative scototaxis but caused crickets to orient randomly with no net directionality. When complex targets were composed of two or more simple rectangular targets which had been previously defined as attractive or unattractive, intermediate responses were obtained. Crickets oriented less toward complex targets than toward simple attractive targets, but oriented more than toward simple unattractive targets. The responses of a female cricket toward an attractive target can be modified by the presence of a chemical signal emitted by previously tested females. When the signal is present females are less likely to orient toward a target that would otherwise be very attractive. This effect was not as great when the females being tested were taken directly from densely populated colonies.

When running on a compensatory treadmill, female crickets exhibit scototactic tendencies similar to those displayed in the arena. When tested on the treadmill over long periods, the amount of time spent orienting toward an attractive target increased.
The effect of wind‐borne odours on the direction of flight in tsetse flies, Glossina spp.
Authors: BURSELL E.
Published: March 2008

ABSTRACT. The direction of flight in tsetse flies (Glossina pallidipes Aust. and G. m. morsitans Westw.) taking off in the presence of certain wind‐borne odours showed a significant upwind shift both in the field and in the laboratory. The average angular deviation between the resting orientation and flight direction was not materially affected by odour, but turns were steered in relation to wind direction if odour was present. Upwind flight in an odour plume was regularly preceded by a standing turn, the fly turning partly or completely into the wind before taking off in upwind flight. This suggests that wind direction was assessed, and flight direction determined, before the fly took off.
Survival of step and ramp changes of temperature by the Queensland fruit fly, Dacus tryoni
Authors: MEATS A.
Published: March 2008

ABSTRACT. Survival time at subzero temperatures is related to both long‐term thermal history and the rate at which the insects are cooled. Insects cooled at one degree per hour survive for up to 3 times as long at a given test temperature than do insects cooled at 1d̀C/min. Survival times are significantly shorter than times taken to freeze. Survival time at an extreme high temperature is related to long‐term thermal history but the rate of heating makes no difference.
Evidence of a sex‐linked diapause response in Papilio glaucus subspecies and their hybrids
Authors: ROCKEY SARAH J. , HAINZE JOHN H. , SCRIBER J. MARK
Published: March 2008

ABSTRACT. Pupal diapause in the eastern tiger swallowtail. Papilio glaucus L., is obligatory or facultative depending on subspecies. The southern subspecies, P. g. glaucus has a facultative diapause, induced by a larval exposure to short photoperiods. In the northern subspecies. P.g. canadensis, diapause is obligatory, occurring in each generation. F*** hybrids inherit the diapause response of their father or respond differently from either parent. The incidence of diapause in hybrids was associated with sex, indicating that the diapause response may be determined by an X‐linked gene.
Daylength and humidity as environmental cues for diapause termination in a tropical beetle
Authors: TANAKA SEIJI , DENLINGER DAVID L. , WOLDA HENK
Published: March 2008

ABSTRACT. Photoperiod is the primary factor controlling termination of adult diapause in the fungus beetle, Stenotarsus rotundus Arrow (Endomychidae: Coleoptera), in a tropical lowland forest. at 9d̀ N. An LD 13:11 h cycle stimulated rapid development of the gonads and flight muscles in both sexes: development was eventually initiated in an LD 12:12 h cycle but was slower. Beetles showed a graded response to intermediate photoperiods. Males consistently initiated gonad development earlier than females, but both sexes developed flight muscles at the same time.

Moisture also influences development: oocytes and flight muscles developed more rapidly at high humidity than at the naturally prevailing low humidity during the dry season. Testis development was less influenced by humidity.

In the field, male gonad development began in late January, suggesting that the beetle can perceive an extremely slight increase in daylength. Ovaries did not contain any visible oocytes before March, but oocyte development was apparent in all females by April. Egg maturation was completed after dispersal from the aggregation site. Females have larger corpora allata than males. These glands increased in size in March when oocyte and/or flight muscle development was initiated. The timing of full development of flight muscles varied slightly from year to year.

Thus, the increase in daylength occurring during the dry season appears to be the cue primarily responsible for development of the reproductive systems and flight muscles. High humidity enhances this response and further prepares the beetles for an active reproductive period at the onset of the wet season.
Conservation of nutrients in larval tissue by cannibalizing honey bees
Authors: WEBSTER THOMAS C. , PENG YING‐SHIN , DUFFEY SEAN S.
Published: March 2008

ABSTRACT. 14C‐phenylalanine appeared in royal jelly secreted by worker honey bees (Apis mellifera, L.) directly after eating 14‐phenyl‐alanine labelled larvae. The amount of labelled phenylalanine in royal jelly was associated directly with the volume of jelly produced. Loss of radio‐label from the workers, in the form of O214C, increased when royal jelly secretion ended. These patterns show that conservation of nutrients in cannibalized tissue is enhanced when the cannibal bees are producing royal jelly. Specific activity of radiolabel in worker bee hypopharyngeal glands was higher than in thoracic muscle, showing selective movement within the bees of a nutrient acquired by cannibalism.
Male accessory gland substances and the control of sexual receptivity in female Culex tarsalis
Authors: YOUNG A. D. M. , DOWNE A. E. R.
Published: March 2008

ABSTRACT. Homogenates of accessory glands from male Culex tarsalis Coquillet (Diptera; Culicidae) were fractionated using gel filtration column chromatography. A component of low molecular weight capable of suppressing female sexual receptivity was obtained and partially characterized. Proteins present in homogenates of isolated accessory glands formed aggregates with other proteins in extracts of whole mosquitoes. Consequently, previous reports of the molecular weight of biologically active components in homogenates from accessory glands from other mosquito species may be inaccurate.

When female Cx. tarsalis were mated with 3H‐leucine labelled males. radioactivity could be found throughout the body of the female 24 h after mating. Autoradiography showed that the radioactivity was incorporated into the cells of various organs, and was not specifically localized in a particular target tissue. Approximately 30% of the total radioactivity transferred to the female was found in the head and thoracic regions, and proteins from the head had a specific activity twice that of the thoracic proteins. Bioassay of isolated body parts from mated and virgin females showed that injections of head tissues from mated females into virgin females suppressed sexual receptivity. These results suggest that the head is involved in the physiological mechanisms resulting in refractory mating behaviour.
The role of Dufour's gland secretions in bees
Authors: HEFETZ ABRAHAM
Published: March 2008

ABSTRACT. Dufour's gland of bees is often hypertrophied and an extremely rich source of diverse natural products. In the ground‐dwelling bees the secretion is mostly used for lining the brood cell with a hydrophobic lining. Whereas in several species the secretion is smeared on the cell walls without any modification, in others the hydrophobic lining is formed only after a chemical transformation of the secretion. The diversity of the chemical means by which hydrophobicity of the brood cells is achieved suggests that it has evolved repeatedly in the bees. In addition to lining their brood cells, several species use Dufour's gland secretion to mark their nest entrance. Analyses of single glands from various species reveal that each bee possesses its own individual composition, expressed in specific relative amounts of each component. Interestingly in the social halictid Evylaeus malachurum, nestmates (considered as sisters) are more similar to each other than non‐related bees. The possible functional evolution of the glandular exudate from structural functions to communication and its implications for our understanding of eusociality in bees, is discussed.
An electrophysiological and behavioural study of insect antifeedant properties of natural and synthetic drimane‐related compounds
Authors: BLANEY W. M. , SIMMONDS M. S. J. , LEY S. V. , KATZ R. B.
Published: March 2008

ABSTRACT. A range of drimane‐related natural and synthetic compounds have been tested in behavioural and electrophysiological screens against larvae of Spodoptera exempta (Walker), S. littoralis (Boisduval), S. frugiperda (J. E. Smith), Heliothis armigera (Hubner) and H. virescens (Fabricius). The most effective compounds are identified and their potential as antifeedants and metabolic poisons is assessed. A consideration of structure in relation to function allows the identification of important functional groups within molecules.
Effects of photoperiod and mating on sex pheromone production and release by oviparae of the aphid Schizaphis graminum
Authors: EISENBACH J. , MITTLER T. E.
Published: March 2008

ABSTRACT. By extraction and bioassay procedures, it is shown that the sex pheromone released by oviparae of the greenbug, Schizaphis graminum (Rondani), during the daylight hours of a light: dark regime, is present in the tibia of the metathoracic legs only during daily photophases.

Shortly after mating, pheromone‐emitting oviparae cease to produce as well as to release the pheromone. This mating‐induced response requires that copulation be completed, and suggests the involvement of sperm or seminal substances transferred by the males to the oviparae during copulation.

Although multiple matings increase the number of eggs deposited by an ovipara, the mating‐induced termination of pheromone production/ release would enhance the chances for mating of neighbouring oviparae. This would result in a further increase in egg production as well as in the number of genetically similar offspring, because neighbouring oviparae are most probably sisters. The phenomenon is discussed in terms of kin selection.
Search orientation of Musca domestica in patches of sucrose drops
Authors: FROMM JEFFREY E. , BELL WILLIAM J.
Published: March 2008

ABSTRACT. The searching tactics of the housefly, Musca dormestica L. (Diptera: Muscidae), have been delineated from digitized pathways of flies walking in patches of sucrose drops arranged in linear (ROW) and hexagonal (HEX) arrays.

The areas covered by flies in ROW and HEX patches are distinctly different, but flies seem not to employ different tactics for the two types of resource arrays. The number of drops located, if at least one drop is found, does not differ between ROW and HEX.

Most quantitative measures of local search remain constant after the first interdrop interval, although feeding time decreases as flies sample successive drops. Local search intensifies after each drop is ingested, with locomotory rate decreasing and turning rate increasing, followed by decay of both measures toward ranging levels.

Searching can be characterized by two movement tendencies resulting from specific, definable, locomotory functions: a forward‐moving tendency is expressed by the fly as it leaves a resource in approximately the same direction as it arrives; and local search is characterized by looping, rather than straight walking, with a variable turning rate that generates a rough ‘zigzag’ superimposed on looping. The two movement tendencies, combined, allow flies to locate resources in a linear arrangement, because of the forward‐moving tendency, and to locate resources not arranged in a linear array because of the ‘noisy’ loop.

M. domestica does not appear to retain and use information gained from one patch of drops in another, so the search tactic of the fly seems therefore to be a compromise between straight movement and circular movement that may be adaptive for an environment subject to frequent changes in the spatial distribution of resources.

Giving‐up‐time, the period between ingesting the last drop and leaving the patch, is a function of the rate of change in the transition from local search to ranging, which is constant in our experiments. If a fly does not encounter another drop while ranging, during which it walks relatively straight, the fly moves out of and away from the patch.
The metabolism of ingested and injected [3H]ecdysone by final instar larvae of Heliothis armigera
Authors: ROBINSON P. D. , MORGAN E. D. , WILSON I. D. , LAFONT R.
Published: March 2008

ABSTRACT. When larvae of Heliothis armigera (Hüber) are fed on a diet containing [3H]ecdysone they produce large quantities of ecdysone 22‐palmitate, probably in the gut. The radiolabel is excreted in the faeces chiefly as ecdysone 22‐palmitate, but appreciable quantities of unchanged ecdysone are also found together with traces of ecdysone 2‐and 3‐acetates. No polar metabolites are found with ingested ecdysone, and the ecdysone probably did not penetrate the gut wall, since on injection into the body, ecdysone was appreciably converted into polar metabolites.