bluuebunny/crossref_metadata_2025 huggingface dataset:
Geographic variation in the incidence of pupal diapause in Asian and Oceanian species of the flesh fly Boettcherisca (Diptera: Sarcophagidae)
Authors: KURAHASHI HIROMU , OHTAKI TETSUYA
Published: March 2008

ABSTRACT. The incidence of pupal diapause was examined in nine species of the genus Boettcherisca Rohdendorf (B.peregrina, B.javanica, B.nathani, B.septentrionalis, B. karnyi, B. koimani, B. timorensis, B. formosensis and B.invaria) collected from various localities in East Asia and Oceanian islands.

Colonies of B.septenrionalis, B. nathani and B.peregrina obtained from temperate regions of Asia and those of B. formosensis and B.peregrina from the continental subtropics entered pupal diapause in response to photoperiod at 20d̀C.

The incidence of pupal diapause showed a geographic gradient in B.peregrina. No photoperiodically induced diapause was observed in the other five species which are indigenous to the tropical or subtropical habitats.

Different species of Boettcherisca seem to have evolved their pupal diapause independently of one another as an ecophysiological mechanism which enabled those species to expand from the tropical to temperate region.
Adult diapause in the Colorado potato beetle, Leptinotarsa decemlineata: effects of external factors on maintenance, termination and post‐diapause development
Authors: LEFEVERE K. S. , DE KORT C. A. D.
Published: March 2008

ABSTRACT. This study tests the effects of temperature, water, food and photoperiod on breaking diapause and resumption of activity (emergence from the soil) in Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae) diapausing under natural winter conditions or at constant temperatures in the laboratory. Behavioural and physiological criteria were used to characterize the various phases of diapause. Three successive phases are distinguished during hibernation: ‘diapause development’ or true diapause, a facultative ‘post‐diapause quiescence’ and, finally, a transient phase of post‐diapause development leading to emergence from the soil. Diapause development is completed within 3 months in the field and its duration depends on temperature. Although they are buried in the soil during this phase, beetles remain sensitive to photoperiod when artificially exposed to it. They do not emerge from the soil when exposed to higher temperatures. Thereafter, they stay in a quiescent state maintained by low temperature, low humidity or lack of food. The response to temperature changes during hibernation. In the soil, activity begins when soil temperature reaches 4–5d̀C, but this temperature is too low to permit postdiapause development. The transient phase has a temperature threshold between 8 and 10d̀C, whereas emergence from the soil occurs only when the temperature exceeds 11d̀C. Post‐diapause development is influenced strongly by temperature and humidity. After emergence, post‐diapause development leads eventually to reproduction. Food is essential for reproduction after diapause whereas photoperiod plays no further role.
The thoracic mechanism for eclosion and digging during the extrication behaviour of Diptera
Authors: MIYAN JALEEL AHMAD
Published: March 2008

ABSTRACT. Dipteran flies escape from the puparium by coordinated contractions of all segments of the body. Whereas special eclosion muscles have been identified in the abdomen and head, none has previously been described in the thorax. Three pairs of large thoracic muscles are described in this paper which are involved solely with eclosion. They have ultrastructures consistent with an ability to supercontract and all three degenerate within 48 h following escape from the puparium. Recordings of electrical activity show them to be rythmically active, coincident with thoracic contractions during eclosion. Many of the non‐fibrillar flight muscles are also incorporated in the eclosion motor pattern and have a precise sequence of activity. Following escape there is a rapid switch from eclosion to flight motor and this is discussed with reference to afferent mediation and changing inputs to the muscles.
Photoperiodic control of adult diapause in the predacious mite, Amblyseius potentillae: repeated diapause induction and termination
Authors: VAN HOUTEN YVONNE M.
Published: March 2008

ABSTRACT. Photoperiodic control of facultative reproductive diapause was examined in females of the phytoseiid mite, Amblyseius potentillae (Garman). Full diapause was induced by rearing the mites from egg to adult under short‐day photoperiods. Egg‐laying females, however, which had experienced a long‐day photoperiodic regime during pre‐imaginal development, could still be induced to enter diapause when they were transferred to a short‐day regime. Diapause development proceeded slowly under a short‐day photoperiod, but was accelerated under long days. During diapause development under short days the photoperiodic sensitivity of the females diminished gradually and ultimately disappeared completely. However, after completion of diapause, sensitivity to photo‐period reappeared. A second diapause could be induced in post‐diapause females under short‐day photoperiods and completed again under long‐day photoperiods. These results show that A. potentillae remains sensitive to diapause‐inducing and diapause‐averting daylengths during the adult stage and that a second diapause may be induced after completion of the first one.
Simulated winter to summer transition in diapausing adults of the lady beetle (Hippodamia convergens): supercooling point is not indicative of cold‐hardiness
Authors: BENNETT LLOYD E. , LEE RICHARD E.
Published: March 2008

ABSTRACT. Adults of Hippodamia convergens Guerin‐Meneville (Coleoptera: Coccinellidae) form massive overwintering aggregations in the Sierra Nevada Mountains of California. These diapausing pre‐reproductive adults may remain in the aggregations for up to 10 months. Beetles were collected from overwintering sites in Nevada County, California, and held at 4d̀C for 6 weeks. In order to simulate the winter to summer transition, the beetles were transferred to 20d̀C and 68% r.h. under a LD 12:12h cycle. Supercooling points increased slightly from ‐ 16d̀C on day 0 to ‐ 12.9CC on day 21. In contrast, low temperature tolerance decreased markedly within 2 weeks. On day 0 nearly all beetles survive 2 h of exposure to ‐ 5d̀C, whereas only 50% survived this treatment on day 4. These data demonstrate the general lack of correlation between the supercooling point and the lower lethal temperature in warm‐acclimated beetles. Within 1 day of transfer to 20d̀C, oxygen consumption decreased by 26%. This decrease continued through day 14 when the rate of oxygen consumption had decreased to 40% of initial values. Beetles acclimated to 20d̀C selected temperatures significantly higher than cold‐acclimated beetles. The parametric shifts observed in this study are consistent with a physiological transition from cold‐hardiness and energy conservation during winter to one of dispersal, feeding and reproduction in summer beetles.
Odour movement, wind direction, and the problem of host‐finding by tsetse flies
Authors: BRADY JOHN , GIBSON GABRIELLA , PACKER M. J.
Published: March 2008

ABSTRACT. Movement of host odour was modelled in natural tsetse habitats with smoke and ultra‐light 7‐cm‐long wind vanes; the speed and direction of the air movements were analysed from video recordings thereof. Wind of <1 ms‐1 did not move in straight lines, since large packets of air (>10 m across) often changed direction together. The rate of this change of direction (meander) correlated negatively with windspeed. In open woodland with a shrubby understorey (in which windspeed was reduced by a factor of >5 from that above the canopy, to ax 0.3 m s‐1), this wind meander fell by 2d̀ s‐1 change of direction for each 0.1 m s‐1 increase in windspeed (r2=0.96). Over open ground without shrub cover, the meander fell by 0.5d̀ s‐1 per 0.1 m s‐1 increase in windspeed (r2=0.85). In both situations, such meandering virtually ceased in winds of > 1 m s‐1. In woodland, the relationship between the direction of air movement near the surface of bare earth (one potential tsetse landing site) and that c. 0.5 m above ground level (flight height) was often weak (r2=0.2‐0.4), but this problem would be reduced if the fly averaged the ground‐level wind for at least 30 s. Odour (smoke) travelling from a source 15 m ‘upwind’ over open ground arrived at a notional tsetse fly for 80% of the time from a direction within 10d̀ of the true source direction. In typical tsetse woodland, however, the ‘odour’ arrived from all directions (including >90d̀ away from the source), with only a 30% bias towards the true source direction (±10d̀). Evidently, tsetse must navigate up odour plumes by means that get round these difficulties‐simple, moth‐type upwind anemotaxis alone seems unlikely to be adequate.
Isolation, physiological characterization, release and sequence elucidation of a hypertrehalosaemic neuropeptide from the corpus cardiacum of the stick insect, Sipyloidea sipylus
Authors: GÄDE GERD
Published: March 2008

ABSTRACT. The corpora cardiaca of the stick insect, Sipyloidea sipylus Westwood, contain peptidic material which elevates blood lipids in migratory locusts, blood carbohydrates in American cockroaches, and activates glycogen phosphorylase in the fat body of the cockroach in a time‐ and dose‐dependent manner. The active principle is found in appreciable amounts only in the corpora cardiaca; slight hyperlipaemia is caused by extracts made from corpora allata and abdominal ganglia, whereas brain, suboesophageal and thoracic ganglia are not active. The adipokinetic activity is already present in corpora cardiaca from second instar (first day) nymphs. The factor retains its adipokinetic activity after boiling for up to 1 h. Conspecific injections of extracts from corpora cardiaca of S.sipylus cause hypertrehalosaemia in ligated stick insects and activate glycogen phosphorylase in non‐ligated S.sipylus. After incubation of corpora cardiaca in vitro in saline with high concentrations of potassium and calcium, one fraction with adipokinetic (in locusts) and hypertrehalosaemic (in stick insects) activity can be isolated from the medium by RP‐HPLC. Fractionation of a methanolic extract of corpora cardiaca from S.sipylus by RP‐HPLC shows that active compounds are confined to apparently three absorbance peaks. The material of the highest absorbance peak was purified to homogeneity by RP‐HPLC, and its amino acid composition determined after acid hydrolysis with HCl and with methanesulfonic acid revealed the residues Asx, Thr(3), Glx, Pro, Gly, Leu, Phe and Trp. The primary structure of this hypertrehalosaemic factor is assigned as a blocked decapeptide, pGlu‐Leu‐Thr‐Phe‐Thr‐Pro‐Asn‐Trp‐Gly‐Thr‐NH2, from its FAB spectrum and metastable scans of its FAB spectrum. The structure is confirmed by synthesis; the synthetic and natural peptide co‐chromatograph, and the synthetic peptide elevates blood carbohydrates in ligated stick insects and activates fat body phosphorylase in non‐ligated S.sipylus.
Distant olfactory response of the onion fly, Delia antiqua, to host‐plant odour in the field
Authors: JUDD G. J. R. , BORDEN J. H.
Published: March 2008

ABSTRACT. Distant olfactory orientation of female adult Delia antiqua (Meigen) to the host‐plant Allium volatile dipropyl‐disulphide (DPDS) was examined in the field using mark‐release‐recapture experiments and observations of flight behaviour. Onion‐reared, post‐diapause, virgin females from a laboratory colony dispersed upwind when released in the centre of 25, 50 and 100 m radius circles of eight 50 μl UDPDS baits. Percentage recapture and dispersal directedness did not decrease as a function of increasing distance to baits. In all cases the mean flight direction of recaptured flies closely correlated with mean wind direction. However, modes of the circular distributions of recaptured flies were located further crosswind when odour‐baits were more distant. When distance was held constant (25 m) and DPDS concentration serially reduced (500–0.05 μ/bait), flies dispersed randomly in the absence of DPDS, crosswind in response to 0.05 μl baits and upwind in response to all other baits. Percentage recaptures on DPDS‐baited traps of all concentrations were significantly greater than unbaited traps. Results from markrecapture studies were corroborated by observations of flight behaviour downwind. Flies located 100 m downwind from 50 μl DPDS baits flew upwind on take off while take‐off flights in the absence of DPDS were random. Our data indicate that Allium volatiles like DPDS are involved not only in the acceptance phase of host‐selection, but also in the first and probably most important stage when onion flies are initiating search long distances downwind. We conclude that D. antiqua orients to host‐plants using olfactory cues from distances that should be classified as long‐range (sensu Kennedy, 1977
Sustained‐flight tunnel responses of male lightbrown apple moth to synthetic sex pheromone
Authors: MUGGLESTON S. J. , FOSTER S. P.
Published: March 2008

ABSTRACT.The upwind flight response of individual male lightbrown apple moths,Epiphyas postvittana(Walker), to twenty combinations of the two pheromone components, (E)‐11‐tetradecenyl acetate (E11‐14:OAc) and (E,E)‐9,11‐tetradecadienyl acetate (E,E‐9,11–14:OAc), was observed in a sustained‐flight tunnel. At the lowest dosage of E11‐14:OAc tested (3 μg), a significantly greater percentage of males flew upwind to and landed at a source emitting 10% E1,E‐9, 11–14:OAc than to all other sources. As the source dosage was increased, males showed decreased specificity of upwind flight to ratios of the two components. However, at the highest dosage of E11‐14:OAc tested (300 μg), the response specificity of males shifted to blends containing lower percentages of E,E‐9,11–14:OAc. The addition of tetradecyl acetate to a blend of the two components did not result in any detectable increase in male response. Analyses of the pheromone glands of individual female Iightbrown apple moths showed that females produced a range of ratios of E11‐14;OAc:E,E‐9,11–14:OAc from 100:2.2 to 100:11.4 with a median of approximately 100:7, reasonably paralleling the peak response of males. Pre‐exposure of males to a blend of the two components, followed by exposure to E11‐14:OAc alone (previously reported as a ‘memory’ effect) resulted in no significant response to E11‐14:OAc alone.
Migratory and targeted flight in seasonal forms of the black bean aphid, Aphis fabae
Authors: NOTTINGHAM STEPHEN F. , HARDIE JIM
Published: March 2008

ABSTRACT. Adult winged forms of Aphis fabae Scop., the spring migrants (fundatrigeniae; alate virginoparae), the summer migrants (alate virginoparae) and the autumn migrants (gynoparae), were flown in an automated vertical wind tunnel, with a small green target presented every 60 s. On average, targeted flight developed in the spring and summer migrants after 19 and 15 min, respectively. However, in autumn migrants targeted flight occurred after 184 min of flight. No evidence of target approach was found up to 30 min prior to this time, although some movement towards the target was observed in the 30 min before the first response of autumn migrants, suggesting that a gradual change from migratory to targeted flight occurred. No correlation was found between aphid weight and the time to first response for spring or summer migrants, but a positive correlation was found for autumn migrants. Flight patterns of autumn migrants, in the absence of a target, are described and compared with flight patterns previously reported for summer migrants.
Ovulation, insemination and mating in the tsetse fly Glossina pallidipes
Authors: WALL RICHARD
Published: March 2008

ABSTRACT. Analyses of the ovulation, insemination and mating of female Glossina pallidipes Austen, were carried out in the field and laboratory. In unmated females, ovulation was delayed until at least the fifteenth day of adult life. The predictable pattern of growth and development of eggs was used to age nulliparous females to the nearest day in the field. Inseminated females first appeared at 5–6 days old and most females became inseminated at 8–10 days of age. There were no significant differences in the age at insemination in Zimbabwe or Kenya. Ovulation had occurred in the field by 10–11 days old. Mating therefore occurs at or just before ovulation. Females were able to mate at up to 12 days old and still produce a viable larva from their first egg. In laboratory flies originating from Uganda, factors which reduced and minimized the effects of disturbance, maximized insemination rate, so that under the best conditions the age at mating was identical to that found in the field. Nevertheless, the insemination rate of Fl generation Zimbabwe flies reared from wild‐caught females was negligible. The differences in the laboratory mating behaviour of the Zimbabwe flies and the flies from the long‐established colony of Uganda origin, are considered to be due to wild G. pallidipes being easily disturbed under laboratory conditions, whereas colony breeding rapidly selects for passivity. The concept of gross differences in G. pallidipes mating behaviour between geographic areas in thus rejected.
The pattern of feeding of first instar nymphs of Schistocerca americana
Authors: CHAPMAN R. F. , BEERLING E. A. M.
Published: March 2008

ABSTRACT The feeding behaviour of nymphs Schistocerca americana (Drury) was recorded throughout the light phases of the first stadium using a behavioural event recording program on a microcomputer. Most food was ingested on day 4 of the stadium, very little on day 1 and none on day 6, the final day of the stadium. Only 26–45% of the total food intake over the stadium occurred during the dark periods and more food was eaten in the last 4 h of each light period than earlier. Feeding occupied only about 5% of the total time. Variation in food intake was a consequence primarily of changes in the numbers of meals. After day 1, the average meal size did not change significantly. Meal length increased relatively slightly compared with meal size as a consequence of an increase in the proportion of time spent feeding in each meal as meal size increased. Meal size was correlated with the length of the previous interfeed suggesting a volumetric regulation. The distribution of pauses within meals was also consistent with the thesis that meal size is governed by the level of excitation in the central nervous system at the start of the meal.
Effects and modes of action of citrus limonoids against Leptinotarsa decemlineata
Authors: LIU YONG‐BIAO , ALFORD A. RANDALL , RAJAB MOHAMMED S. , BENTLEY MICHAEL D.
Published: March 2008

ABSTRACT Limonin and its five derivatives were evaluated in feeding bioassays for depression effects on feeding, growth and development of the fourth stadium Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae). Epilimonol and limonin diosphenol were most effective in depression of feeding and growth, with ED50s 10 and 8 μg/cm2. At a dosage of 31.6 μg/cm2, epilimonol, limonin diosphenol and limonin caused both significant feeding reduction and developmental delay, while deoxylimonol, tetrahydrolimonin and limonol were not effective. Mouth‐part coating and antifeedant bioassays show that feeding inhibition at host acceptance level seems to be the primary mode of action of epilimonol and limonin diosphenol.
Recovery of learning responses by honeybees following a sublethal exposure to permethrin
Authors: MAMOOD AMED N. , WALLER GORDON D.
Published: March 2008

ABSTRACT A classical conditioned response was used to evaluate the learning behaviour of honeybees (Apis mellifera L.) which survived a sublethal dose of permethrin. Treated bees had lower learning response levels than untreated bees for 3 days, but regained normal learning ability on the fourth day after exposure. However, bees trained prior to exposure showed no significant effect of permethrin on their conditioned response.
Endocrine regulation of female contact sex pheromone production in the German cockroach, Blattella germanica
Authors: SCHAL COBY , BURNS EDINA L. , BLOMQUIST GARY J.
Published: March 2008

ABSTRACT The amount of the major component of the cuticular sex pheromone, 3, 11‐dimethyl‐2‐nonacosanone, on individual female German cockroaches, Blattella germanica (L.), as a function of age was determined by gas‐liquid‐chromatographic analysis. Accumulation of phermone increased with age in both virgin and mated females. During the first gono‐trophic cycle, the pheromone accumulated most rapidly when oocyte growth rates were maximal (days 5–10), and least rapidly while the female carried an ootheca (days 11–32). Pheromone accumulation was similar in virgin and mated females when the same physiological stages (determined by oocyte maturation) were considered. Inhibition of Juvenile Hormone release, through allatectomy, chemicals (precocene or fluoromevalonate), or through mechanical egg case implants, suppressed or delayed pheromone production and oocyte growth. The Juvenile Hormone analogue ZR512 induced allatectomized or head‐ligated females and females with chemically or mechanically inhibited corpora allata to produce pheromone and enlarge their basal oocytes. Finally, ZR512 applied to intact females stimulated pheromone production in a dose‐dependent manner.
Circadian rhythms in the blowfly, Phormia terraenovae: control of phase within the range of entrainment
Authors: ASCHOFF JURGEN , PAUL URSULA VON SAINT
Published: March 2008

ABSTRACT Locomotor activity of individual blowflies, Phormia (=Protophormia) terraenovae R.D. (Diptera, Calliphoridae) was recorded by means of running wheels. A few days after emergence, adult flies were placed in the wheels and exposed to at least two of four light‐dark cycles (LD) differing in cycle duration T (LD 11:11, 12:12, 13:13 and 14:14 h). The intensity of illumination was 400 lux in L and 2 lux in D. From the actograms, phase‐angle differences were read off between onset of activity and light‐on (ψ/onset), and between end of activity and light‐off (ψend)‐ Within the range of entrainment, ψ changed systematically from negative values in T=22 h to positive values in T=28 h: the mean change in ψ per hour change in T, expressed in degree of the full circadian cycles, was 20o. Standard deviations of ψ around its mean were computed for ten‐cycle intervals; in ψonset and in ψend standard deviation was minimal when 4ψ was close to zero, and increased steadily with increasing negative or positive ψ ‐values.
Metabolic rates of tsetse flies in the field as measured by the excretion of injected caesium
Authors: HARGROVE J. W. , COATES T. W.
Published: March 2008

ABSTRACT Teneral tsetse flies, Glossina morsitans morsitans Westw., were injected with labelled caesium (137Cs) <18 h after emergence and released in the Zambezi Valley of Zimbabwe between May 1983 and June 1984, and again in February 1985. Radioactivity in flies recaptured time t days after injection indicated a three‐stage exponential loss of caesium, identical for both sexes. For t≫4 the estimated rate constant (‐0.119 per day) was significantly lower than for 4≫t≫12 (–0.252 per day). By day 15 about 97% of the isotope had been excreted; thereafter the loss rate fell by an order of magnitude. The data for t>4 days were well fitted by the sum of two exponentials but no smooth function was found to fit all three phases. The loss rate from the rapidly metabolized pool increased exponentially with temperature at the same rate as for male tsetse kept in the dark in the laboratory. However, the loss rate in the field was lower at every temperature, suggesting that these flies live at 2–6oC lower than the average Stevenson screen temperature. Published estimates of hunger cycle and daily flight durations, made on the basis of measured rates of caesium excretion, are invalid because they use the assumption that flies are living in the field at screen temperatures. The data suggest that both sexes have the same metabolic rate up to the age of about 15 days, which implies that the females (being larger and having to nourish a larva in the latter stages of this period) must be less active and/or live at even lower temperatures than the males.
Maturation of the tsetse fly Glossina pallidipes (Diptera: Glossinidae) in relation to trap‐orientated behaviour
Authors: LANGLEY P. A. , HARGROVE J. W. , WALL R. L.
Published: March 2008

ABSTRACT The fat free dry weight or residual dry weight of the thorax (Trdw) increased linearly for the first 10 days of adult life in both sexes of G.pallidipes in the laboratory as their flight muscles developed. Using ovarian dissection to estimate the ages of nulliparous adult females of G.pallidipes, the Trdw was also found to increase linearly for at least 14 days in the field. Significant increases in pteridine fluorescence with age were measured in both laboratory‐reared males and females of known chronological age and in wild‐caught nulliparous females whose ages were estimated by ovarian dissection. A linear relationship existed between pteridine fluorescence and wing fray category for a wide range of ages of field‐caught flies of both sexes. A stationary trap baited with ox odour was selective in that only the hungrier portion of the flies attracted to it actually entered. However, it was not selective in terms of the mean ages of flies caught. Comparisons were made of the age compositions of catches of both sexes of G.pallidipes attracted to a stationary trap baited with synthetic odours or to a mobile electrified net by plotting Trdw values against pteridine fluorescence. Nulliparous females were not attracted to the stationary trap, but were attracted to the mobile bait. Males of all ages appeared to be equally attracted to both. It is concluded that nulliparous females do not respond to host odour stimuli until they are ready to mate, perhaps relying on the energy‐conserving strategy of watching for a moving host animal before attempting to feed. Alternatively, synthetic odours may differ from natural host odours in terms of their attractiveness to young females. Males, however, probably exhibit dual sexual and feeding behaviour by responding to an odour‐baited stationary trap even when young.
A supravital staining technique for honey bee spermatozoa
Authors: LOCKE SARAH J. , PENG YING‐SHIN , CROSS NICHOLAS L.
Published: March 2008

ABSTRACT A new supravital staining technique is described for honey bee, Apis mellifera L., spermatozoa using the fluorochromes, propidium iodide and Hoechst 33342 (H342), a bis‐benzimidazole derivative. Propidium iodide binds to the DNA of sperm which lack membrane integrity and H342 binds to the DNA of all sperm. This assay is a simple and rapid method for determining the percentage nonviabiiity of a male honey bee's sperm. The recommended staining procedure is to incubate sperm in a solution of 5 μ.g/ml H342 and 10 μ.g/ml propidium iodide in modified Kiev solution for 15–20 min. After incubation, wet mounts of the sperm‐stain suspension are examined using fluorescence microscopy. Percentage nonviabiiity is determined by the ratio of propidium iodide stained sperm to H342 stained sperm.
Feeding response of the stable fly, Stomoxys calcitrant L., to blood fractions and adenine nucleotides
Authors: ASCOLI‐CHRISTENSEN ANN , SUTCLIFFE JAMES F. , STRATON CARLA J.
Published: March 2008

Abstract Feeding responses of the stable fly (Stomoxys calcitrans L., Diptera: Muscidae) to blood fractions and saline‐based diets were studied in an artificial feeding device. Flies fed equally on whole blood, plasma and erythrocyte fractions while resuspended platelets or the buffy layer did not stimulate feeding. Evidence from filtration studies indicates that plasma contains both less‐than‐5000D and greater‐than‐100,000D phagostimulatory components. ATP, ADP and AMP in saline stimulate feeding in this insect in a dose‐dependent manner. cAMP also stimulates feeding in the range of concentrations tested. It is argued that the less‐than‐5000D phagostimulant may be one or more of these adenine nucleotides.
The role of the frontal ganglion and corpora cardiaca/corpora allata complex in post‐feeding weight loss in adult Heliothis zea
Authors: BUSHMAN DAVID W. , NELSON JUDD O.
Published: March 2008

Abstract A post‐feeding diuretic response has been observed in adult Heliothis zea (Boddie) (Lepidoptera: Noctuidae). 2‐day‐old starved adults which were allowed to feed to repletion on a 10% (w/v) sucrose solution lost 49.1% (females) and 85.8% (males) of the weight of the ingested meal during the first hour following feeding. Ligation between head and thorax or frontal ganglionectomy, when performed immediately following feeding, each resulted in a significant and permanent reduction in this normal weight‐loss. Injection of homogenates of the corpora cardiaca/corpora allata (CC/CA) complex into non‐ligated insects immediately after feeding also reduced significantly the post‐feeding weight‐loss, but this inhibition was transient and disappeared after 1 h. Dissection and weighing of the crop from either ligated, frontal ganglionectomized, or CC/CA‐injected insects confirmed the crop as the predominant site of fluid retention in each case. We suggest that a soluble antidiuretic factor from the CC/CA acts in conjunction with the frontal ganglion to control the rate of crop emptying and subsequent diuresis by regulating the volume of ingested fluid that is passed into the haemolymph from the crop/midgut.
Physiology of interspecific chemical communication in Heliothis moths
Authors: CHRISTENSEN THOMAS A. , GEOFFRION SABRINA C. , HILDEBRAND JOHN G.
Published: March 2008

Abstract Electroantennograms were recorded from the antennae of adult male and female corn earworms, Heliothis zea (Boddie). A total of seventeen female moth sex pheromone components from several species were tested. Of these, two components elicited significantly greater responses than the other fifteen. These were (Z)‐11‐hexadecenal, a conspecific component, and (Z)‐9‐tetradecenal, a component found in the pheromone blend of a sympatric species H.virescens (F.) that inhibits attraction of H.zea males. The results from dose‐response and selective adaptation studies indicate that there are separate populations of receptors for these two chemical signals on the antenna of male H.zea. The more sensitive population is selective for (Z)‐11‐hexadecenal, while the less sensitive one responds to (Z)‐9‐tetradecenal. These findings provide a physiological basis by which H.zea males can distinguish the interspecific repellent from the conspecific pheromone blend. It is likely that this discrimination contributes to reproductive isolation between these two species.
The effect of colour on the numbers, age and nutritional status ofGlossina tachinoides(Diptera: Glossinidae) attracted to targets
Authors: GREEN C. H.
Published: March 2008

AbstractThe effect of colour on the attractiveness of cloth targets forG.tachinoidesWestwood was investigated, using electrified nets. The ages and nutritional states of tsetse caught by different targets were also studied. With targets of cloth and mosquito netting panels, phthalogen blue was the most attractive colour, and yellow the least, with black, red, violet and white intermediate. The strongest landing responses in females occurred on UV‐reflecting white cloth. In males, landing was high with all colours except yellow. Colour combination targets were no better than all‐blue targets when mosquito netting side‐panels were present; in their absence, blue‐and‐white targets were over twice as good as all‐blue targets. No consistent differences in ages or nutritional states were found between tsetse caught by differently coloured targets, but those landing directly on the cloth portion of a target had lower fat reserves than those intercepted on an adjacent netting panel.
Life span and ovarian dynamics of the pine beauty moth, Panolis flammea (D&S): the effect of low temperatures after adult emergence on reproductive success
Authors: LEATHER SIMON R.
Published: March 2008

Abstract Adult female Panolis flammea were kept at 2oC either immediately after emergence from the pupae or immediately after mating, for periods ranging from 5 to 20 days and then placed at 15oC together with a male moth, food supply and suitable oviposition site (Pinus contorta foliage). Weight loss over the storage period was directly proportional to the time spent at 2oC irrespective of whether the moths were virgin or mated. Pre‐oviposition period decreased significantly from the control after more than 5 days at 2oC, but there was no significant difference between late mated and early mated moths. The post‐storage life span of late mated and early mated moths decreased in proportion to the time spent at 2oC but late mated moths had significantly longer life spans than early mated moths. Moths mated prior to storage were significantly less fecund than moths mated after storage except those moths kept at 2oC for 20 days where the fecundities of both treatments were identical (c. 45 eggs/female). These results are discussed in relation to the conditions likely to be experienced by P.flammea in the field and their bearing on the population dynamics of this insect.
Circadian rhythmicity and development of the behavioural response to sex pheromone in male brown‐banded cockroaches, Supella longipalpa
Authors: LIANG DANGSHENG , SCHAL COBY
Published: March 2008

Abstract The effects of age, time of day and pheromone concentration on the responsiveness of the male brown‐banded cockroach, Supella longipalpa (F.), to female volatile sex pheromone were examined. Male response increased with age and peaked 10 days after the imaginal moult. A diel periodicity of responsiveness was observed, with greater responses in the scotophase. The behavioural response was dose‐dependent and its diel periodicity was most obvious when intermediate pheromone concentrations (e.g. 0.01 female equivalents) were used. Higher concentrations obscured the periodicity by eliciting greater responses in the photophase, while the lower concentrations did so by decreasing the response in the scotophase. Following entrainment to a LD 12:12 h cycle, the periodicity of response to 0.01 female equivalents of pheromone persisted for at least 54 h under continuous darkness, further demonstrating a true circadian rhythm.
Response specificity of male olfactory receptor neurones for the major and minor components of a female pheromone blend
Authors: AKERS R. PATRICK , O'CONNELL ROBERT J.
Published: March 2008

Abstract The sex attractant of the female redbanded leafroller moth, Argyrotaenia velutinana (Walker), is a blend of seven compounds. Specialized olfactory receptor neurones had been found for only two of the compounds, (Z)‐11‐tetradecenyl acetate (Z11‐14:Ac) and (E)‐11‐tetradecenyl acetate (E11–14:Ac). These receptor neurones were always found in pairs within the long trichoid sensilla, which are the most abundant multi‐pored sensilla on the male antenna. A systematic survey of all regions of the male antenna with standard extracellular recording techniques was undertaken to find receptor neurones responsive to the remaining five minor components of the female pheromone. Of the 113 long trichoid sensilla sampled, all contained two receptor neurones, one specialized for Z11–14:Ac and a second specialized for Ell –14:Ac. A comparable number of recordings were then obtained from the less abundant classes of multi‐pored sensilla. Two new receptor neurone types were found, responsive to the minor pheromone components (E)‐9‐dodecenyl acetate (E9‐12:Ac) and (Z)‐9‐dodecenyl acetate (Z9‐12:Ac). Scanning electron micrographs indicated that these recordings were obtained from shorter, narrower trichoid sensilla. The majority of these sensilla appeared to contain three neurones capable of spontaneous action potential production. In each sensillum, only one receptor neurone appeared to respond to stimulation with a minor component of the female blend. The remaining two neurones did not respond to the chemical stimuli evaluated.
Orientation of tsetse flies to wind, within and outside host odour plumes in the field
Authors: GIBSON GABRIELLA , PACKER M. J. , STEULLET PASCAL , BRADY JOHN
Published: March 2008

Abstract Free‐flying wild tsetse flies (Glossina pallidipes Aust. and G. m. morsitans Westw.) were video recorded in Zimbabwe as they flew within an artificial host odour plume at 3, 7 or 15 m from the source, or in no odour, with and without a 0.75 m2 vertical, black visual target present aligned with the wind. With no visual target present, flights in odour were strongly biased upwind, and in the absence of odour strongly biased downwind. With the target present, between 16% and 40% of the upwind approaching flies responded visually as they passed the target, by circling it, in proportion to the proximity of the source (taken to be proportional to the mean odour concentration). Crosswind approaching flies (for whom the target will have been visible for some metres away) circled more frequently (34–56%), but without obvious correlation with the odour concentration. Circling flies also responded orthokinetically, by slowing down as they passed the target. The departure directions relative to the wind of flies leaving the target were significantly affected by the odour concentration. At 3 m they left the target in all directions, except possibly avoiding due upwind. At 7 m they left with an obliquely upwind bias, but at 15 m and also in no odour, they left with a strong crosswind bias.
Effects of dextrin and cellulose on feeding and reproduction in female brown‐banded cockroaches, Supella longipalpa
Authors: HAMILTON ROBERT L. , SCHAL COBY
Published: March 2008

Abstract Food consumption and reproduction were compared through two gonotrophic cycles in female brown‐banded cockroaches, Supella longipalpa (F.), fed a standard rat food diet which had been serially diluted with methyl cellulose, alpha cellulose or dextrin. Females did not increase daily intake to compensate for dilution, and reproductive rate was highly dependent upon the degree of dilution of the diet. With increasing dextrin concentrations, digestibility increased, but reproductive rate, size and mass of oothecae, and efficiency of food utilization progressively decreased.

On diets containing 75% rat food and 25% methyl cellulose, females consumed minimal amounts of food and 80% of the females did not mate or produce oothecae within 30 days. On identical diets containing 25% alpha cellulose, food digestibility decreased and females ate significantly more than females fed 25% methyl cellulose, but less than females fed rat food. Many (65%) females fed 25% alpha cellulose produced oothecae which were smaller and took longer to form than in control females fed on rat food. At concentrations higher than 50% of either methyl or alpha cellulose daily intake was further reduced and females died rapidly.
A comparative study of sex pheromone reception in the Hadeninae (Lepidoptera: Noctuidae)
Authors: RENOU MICHEL , LUCAS PHILIPPE , DORE JEAN‐CHRISTOPHE , LALANNE‐CASSOU BERNARD , CHAMBON JEAN‐PIERRE , COCQUEMPOT CHRISTIAN
Published: March 2008

Abstract A comparative study of the olfactory responses to pheromone compounds was performed in twenty‐four species of Hadeninae. Electroantennograms (EAG) were recorded on male moths in response to thirty compounds and the response profiles of each species were analysed by factorial correspondence analysis. A limited number of molecules were found active and the most effective stimuli were Z9 tetradecenes and Z11 hexadecenes. The species of the Mythimna genus were most sensitive to aldehydes. Tholera decimalis did not respond to any of the molecules tested. The species belonging to the Mamestra and the Orthosia genera responded to a variety of molecules and no simple correlation was found between the genus and the EAG sensibility. Pheromone reception is discussed in relation to the taxonomy and the evolution of olfactory communication in Hadeninae.
Food consumption and utilization responses to dietary dilution with cellulose and water by velvetbean caterpillars, Anticarsia gemmatalis
Authors: SLANSKY FRANK , WHEELER GREGORY S.
Published: March 2008

Abstract Dilution of an artificial diet with water or cellulose to nutrient levels of 32% (undiluted), 19% and 10% fresh weight (fw) resulted in increased fw and dry weight (dw) food consumption (both absolute amounts and weight‐relative rates) by velvetbean caterpillars, Anticarsia gemmatalis Hübner. Despite these increases, the absolute amount and relative rate of nutrient intake by the caterpillars declined with dilution, as did their dw gain and dw (% fw) and lipid (% dw) contents. The proportion of consumed food (dw, including cellulose) that was digested and absorbed declined with increased dietary cellulose; however, the proportion of consumed nutrients (dw, excluding cellulose) that was digested and absorbed was not affected by the presence of cellulose, although it increased slightly (but significantly) with dietary water. The efficiency with which the absorbed nutrients were converted to biomass energy showed a negative relationship with the various measures of food consumption and thus a positive relationship with dietary nutrient level.

The compensatory increases in feeding mitigated the deleterious impact of dietary dilution on growth, which would have declined further without the increased feeding. These data suggest that food consumption is regulated primarily through an evaluation of food nutrient level, and that the metabolic costs associated with the increased consumption and processing of food may be substantial, especially on the most diluted diets. Another hypothesized cost of increased feeding, reduced efficiency of digestion and absorption as food presumably passes more rapidly through the gut, was not detected.
Effects of starvation and sucrose feeding on corpora allata of last instar larvae of Manduca sexta: in vitro activity, size, and cell number
Authors: GARZA LOURDES M. DE LA , BHASKARAN GOVINDAN , BARRERA PUNNEE , DAHM KARL H.
Published: March 2008

Abstract Larvae of the tobacco hornworm moth Manduca sexta starved for the first 3 days of the last (fifth) stadium undergo a supernumerary moult. If they are provided with sucrose during the starvation period, they develop into normal pupae although pupation is delayed. The activities of the corpora allata (CA) from normal, starved, and sucrose fed larvae were followed through the fifth stadium with a radiochemical assay for Juvenile Hormone (JH) biosynthesis. An attempt was made to correlate CA‐activity with CA cell number, size, and protein content.

In CA of normally fed larvae the rate of JH synthesis declined to undetectable levels by day 4 which was also the time of exposure of the dorsal vessel. In CA of starved larvae, the rate of JH synthesis at first decreased but began to increase on day 3 and reached a peak value by day7, at which time head capsule slippage occurred. In CA of sucrose fed larvae, the rate of biosynthesis declined as in normal larvae but the decline was extended over a longer period. Exposure of the dorsal vessel was delayed in the same manner and occurred on days 7–9. The major JH in all cases was JH‐II.

The CA comprise c. 150 cells in the early fifth stadium, and this number remained constant during the fifth stadium in all three feeding regimens. In normal larvae, CA size and protein content increased several‐fold during the stadium whereas in starved and sucrose‐fed larvae they increased slowly and in agreement with the altered timing of developmental events. In none of the groups was the CA activity pattern correlated with morphometric changes of the CA. The rates of JH biosynthesis were not closely correlated with published JH titre curves. The in vivo mechanisms for regulation of JH production remain to be elucidated.
Temporal events of gypsy moth vitellogenesis and ovarian development
Authors: LAMISON CRAIG D. , BALLARINO JOANNE , MA MICHAEL
Published: March 2008

Abstract The vitellogenic period of gypsy moth ovarian development starts on day 3 of the pupal stage and continues through adulthood. During this period, rapid increases occur in follicle size, protein content, and wet weight of the ovary. Patency is observed on day 3 of the pupal stage.

Pre‐vitellogenic follicles are formed in the last larval stadium. Newly formed follicles detach from the germarium on day 4, and increase rapidly to 140 per ovariole at the end of the last larval stadium. The pre‐vitellogenic follicles are uniformly around 50 um in diameter. No vitellogenin is incorporated into the oocytes until the pupal stage.

Polyacrylamide gel electrophosesis (PAGE) in the presence of sodium dodecylsulphate (SDS) analysis of male and female haemolymph samples and vitellogenic ovaries demonstrates the presence of two female‐specific subunits of vitellogenin of 180 kD and 160 kD. These proteins are detected only in haemolymph and ovarian extracts of vitellogenic females. The molecular weight of the native protein determined by size exclusion chromatography is approximately 400–420 kD.

A highly sensitive double antibody sandwich enzyme‐linked immunosorbent assay (ELISA) was developed to monitor the temporal changes in vitellogenin titre in haemolymph. Vitellogenin production starts on day 2 of the last larval stadium, reaching a maximum level by day 6 of the last larval stadium, and decreasing in the late pupal stage as vitellogenin was internalized into the oocytes. This is the first report of vitellogenin production occurring in the larval stage of a holometabolous insect. The fact that vitellogenin production and uptake occur during different stages of development in the gypsy moth, opens up some interesting questions concerning the underlying regulatory mechanisms controlling each process.
Flight behaviour of the bird cherry aphid, Rhopalosiphum padi
Authors: NOTTINGHAM STEPHEN F. , HARDIE JIM , TATCHELL G. M.
Published: March 2008

Abstract Seasonal winged forms of the bird cherry aphid, Rhopalosiphum padi L., were flown in an automated flight chamber. During their maiden flights, autumn migrants (gynoparae) had a greater initial rate of climb than summer (exules) and spring migrants (emigrants). Autumn migrants, presented with a laterally‐positioned green‐illuminated target for 2.5 s during each minute of flight, flew for a longer period before responding to the target (110 min) than summer migrants (36 min), while spring migrants responded after an intermediate time (72 min). This period is equivalent to the migratory phase of flight. The summer migrants were maximally responsive to targets illuminated by green monochromatic light (X, 555 nm). Targets illuminated with ultraviolet (γλ 360 nm) were attractive during the migratory and green‐responsive phases of flight, but infrared (γλ700 nm) wavelengths were not attractive. The results are discussed with respect to aphid behaviour in the field.
Diapause and seasonal life cycle strategy in the house spider, Achaearanea tepidariorum (Araneae, Theridiidae)
Authors: TANAKA KAZUHIRO
Published: March 2008

Abstract In order to elucidate the mechanism regulating its seasonal life cycle, the photoperiodic response of Achaearanea tepidariorum has been analysed. Nymphal development was faster in long‐day and slower in short‐day photoperiods. The combined action of low temperature, poor food supply and short daylength induced diapause at an earlier developmental stage than short days alone. Thus, photoperiod is a primary factor inducing nymphal diapause, but the diapausing instar is influenced by both temperature and food supply. Hibernating nymphs became unresponsive to photoperiod in late December. After hibernation, however, sensitivity was restored and the nymphs remained sensitive to photoperiod throughout their life. This spider could also enter an imaginal or reproductive diapause. Photoperiod was again a primary inducing factor and temperature modified the photoperiodic response to some extent. The induction of the reproductive diapause was almost temperature‐compensated whereas development was not. So the involvement of a photoperiodic counter system was suggested. Irrespective of whether the nymph had experienced diapause or not, the imaginal diapause was induced in response to a short‐day photoperiod after adult moult. Based on these observations, the seasonal life cycle and the adaptive significance of nymphal and imaginal diapause are discussed.