Showing papers in "Journal of Insect Physiology in 2000"

TL;DR: Physiological and biochemical mechanisms of dehydration tolerance and resistance in dormant insects and some other invertebrates are reviewed, as well as linkages of dehydration with energy use and metabolism, with cold hardiness, and with diapause.

TL;DR: Three aphid species were compared with respect to ability of enhancing the nutritional quality of their host plants and changes in the phloem induced by both S. graminum and D. noxia are expected to affect the aphids' dependence on nutritional supplementation by intracellular symbionts (Buchnera).

TL;DR: Results indicate that eicosanoids play a role in the immune response of S. exigua, and suggest strongly that X. nematophilus inhibits its eICosanoid pathway, which then results in immunodepressive haemolymph septicemia.

TL;DR: Transgenic rice plants expressing snowdrop lectin were screened for resistance to green leafhopper, and GNA binding to glycoproteins in gut tissues showed that BPH contained more "receptors" than GLH, and that the binding affinity was stronger, particularly in the midgut.

TL;DR: The salivary glands are vital to the biological success of ixodid ticks and the major route for pathogen transmission, and key regulatory and secretory gland proteins are purified and their genes cloned and sequenced.

TL;DR: It is suggested that a low JH titre in honey bee workers permits the onset and accumulation of Vg in haemolymph, whereas high JH levels turn off Vg synthesis.

TL;DR: The complexity of salivation and the relation of the results obtained to the behaviourally known secretion periods is discussed.

TL;DR: It is suggested that calcium is a factor required for adhesion of plasmatocytes, and that it also functions to enhance their phagocytic action.

TL;DR: The electrophoretic profiles of esterase activity in protein extracts from coumaphos and permethrin-resistant strains compared to the susceptible strain revealed distinct differences, which inhibitor studies attributed to carboxylesterases.

TL;DR: The results show that reproduction in B. terrestris is strongly affected by the social environment and the influence of the environment on reproduction is mediated by JH, and the rate of JH biosynthesis measured in vitro is not a reliable indicator ofJH titer or ovarian development in the bee.

TL;DR: It is concluded that mild winter temperatures may be detrimental to some overwintering insects, particularly species that do not feed following winter diapause, and low temperature and even freezing are beneficial, allowing conservation of energy reserves to maintain high survival and potential fecundity.

TL;DR: The total hemocyte count increased two days after application, indicating an overall stimulation of the immune system, but declined to a value below that for uninoculated controls by day four, and the differential haemocyte count showed that the initial increase in total haemocytes was primarily due to a larger number of coagulocytes.

TL;DR: Insect sulfakinins, peptides which display substantial sequence similarities with the vertebrate gastrin/CCK peptide family, significantly inhibit food uptake in fifth instar nymphs of the locust, Schistocerca gregaria.

TL;DR: The results suggest that insect chill-coma varies with a species' ability to maintain its resting potential at low temperatures, and appears to be related to the rate of decline in each species' resting potential.

TL;DR: It is suggested that all PSP1, GBP, PP and CAP family members are homologs that likely have multiple biological activities and should be referred to as members of the "ENF" peptide family.

TL;DR: This is the first study to link resistance intrinsic to the physiology of the insect and resistance conferred by host plant chemistry to a single mechanism, i.e., midgut cell sloughing, and it is suggested thatSloughing of infected midg gut cells occurred at a higher rate in insects that fed on cotton compared to the other two diets, and that susceptibility to mortal infection by AcMNPV-hsp70/lacZ is decreased on cotton.

TL;DR: The data suggest that the fructose moiety of ingested sucrose is assimilated very efficiently and may be preferentially respired by the aphid, and that the glucose moieties are incorporated into oligosaccharides by the transglucosidase activity of the gut sucrase at high sucrose concentrations.

TL;DR: The braconid Aphidius ervi Haliday (Hymenoptera, Braconidae) is an endophagous parasitoid of the pea aphid, Acyrthosiphon pisum (Harris) (Homoptera), and the adaptive significance of host castration is discussed.

TL;DR: These experiments demonstrate the sensitivity of insect behaviour to disruption by anaesthesia or rough handling, and it is preferable to avoid anaesthetising flies that are to be used in behavioural studies.

TL;DR: The results showed that during the first 9 days after inoculation, parasitized and polydnavirus-inoculated M. sexta larvae died more quickly and at higher levels than nonparasitized and sham-injected controls, suggesting that the cellular immune response was a factor in conferring resistance to fatal infection by AcMNPV-hsp70/lacZ.

TL;DR: Sorbitol present in diapausing silkworm eggs does not appear to serve as an antifreeze, but as an strong arresting factor of embryonic development, and results show that a decrease in sorbitol releases the embryos from diapause at the termination of diAPause.

TL;DR: The stronger behavioural response to the banana volatile bouquet and to the binary mixture serves to underline the multireceptor nature of the dorsal organ response to food odour in Drosophila.

TL;DR: Gene expression during cold acclimation at a moderately low temperature (15 degrees C) was studied in Drosophila melanogaster using a subtraction technique and the function of DCA was discussed in relation to the possible regulation of cytosolic Ca(2+) concentration.

TL;DR: The ability to synthesize and sequester amino acids as storage proteins during the adult stage has wide-ranging implication for protein management in insects, particularly those that are long-lived and have flexible schedules of reproduction.

TL;DR: JH titres of bees under conditions of accelerated behavioural development were significantly higher than same-aged bees under more typical conditions, even before the onset of foraging.

TL;DR: It is suggested that ecdysteroids are involved in regulation of reproduction in B. terrestris, a bees that differ in their behavior, reproductive status and social environment.

TL;DR: Seasonal analysis of two dafps revealed differences on the transcriptional level, suggesting that DAFPs may serve somewhat different functions, and some of the cDNA clones isolated display significant divergence at the primary amino acid level, yet, maintain conservation of key residues that are presumably important for structure and function of antifreeze proteins in this cold-hardy organism.

TL;DR: A new in vivo assay for estimating PM permeability is described, which allows for assessment of the permeability of the caecal membrane, a structure that separates each caecum from the gut lumen.

TL;DR: The results demonstrate that several critical features of cold hardiness in the wasp are derived from biochemical and physical attributes of the host.

TL;DR: In this review, sophisticated autonomous regulatory mechanisms have been identified in Malpighian tubules that play homeostatic roles, preserving haemolymph osmolality or ionic composition.