Showing papers in "Journal of Insect Physiology in 1991"

TL;DR: It is demonstrated that differences in juvenile hormone titres among bees performing different age-dependent tasks are a consequence of changes in rates of hormone synthesis by the corpora allata, and that the radiochemical assay will be useful in further studies of hormonal regulation of bee behaviour.

TL;DR: The activity of polydnavirus was abolished by pretreatment with psoralen and ultraviolet irradiation which suggests the virus must be transcriptionally active to alter the host encapsulation response.

TL;DR: Comparison of juvenile hormone and edcysteroid titres suggests that ecdysteroids are not involved in the regulation of age polyethism but may play a role in theregulation of reproduction in honey bees.

TL;DR: It was concluded that pheromone binding protein can act as a solubilizer or carrier in the sensillum lymph and be inactivator function of the binding protein.

TL;DR: It is suggested that ammonia, a major nitrogenous waste product of the aphid, is utilized by the bacteria in untreated aphids, but it is detoxified, primarily by incorporation into glutamine in the aposymbiotic aphid.

TL;DR: The capability of amino acid conversion of the aphid was investigated and the following amino acids were found labelled exclusively in the symbiotic aphids: arginine, histidine, isoleucine and/or leucine, lysine, phenylalanine, threonine and valine, suggesting that-these so-called essential amino acid were produced with the aid of symbionts.

TL;DR: Ligature experiments demonstrated that head ligation in last-instar larvae, counteracted the azadirachtin-induced interference with pupation, pointing to an “aza-sensitive head factor”.

TL;DR: The present experiments, unlike other immune reactions, fail to demonstrate any interference of azadirachtin with the prophenoloxidase-activating system since the melanin production was not reduced when this system was stimulated by trypsin or by the presence of bacteria in the haemolymph.

TL;DR: The growth and function of Microplitis demolitor teratocytes in Pseudoplusia includens larvae was investigated, and alterations in growth that were very similar to parasitism by M. demolitor were exhibited.

TL;DR: Cellulase and its component activities were measured in the guts of larvae, minor soldiers and the four categories of workers in Macrotermes michaelseni and M. subhyalinus to assess the distribution of cellulase activity among the castes and in fungal material associated with colonies of both species.

TL;DR: Considering the different effects of bafilomycin and vanadate on fluid and ion secretion a new working hypothesis for a transport model is proposed.

TL;DR: The results suggest that the calyx and venom fluids are directly able to depress the function of the prothoracic gland and the competence of prothornic gland to respond to PTTH.

TL;DR: Mated females that were maintained on water for 4 days before ingesting blood were more likely to develop eggs than were unmated females, and juvenile hormone topically applied to sugar-deprived, blood-fed unmated Female enhanced egg development.

TL;DR: 2-heptanone had a temporary, repulsive effect on the visitation of flowers by foraging bees, hence it seems to act as a “forage-marking” pheromone.

TL;DR: For the first time an age-dependent hyperlipaemic response for octopamine is reported, which was very similar to the age-response curve for the cricket's own adipokinetic hormone, and a correlation between ovarial development and the sugar and lipid responsiveness tooctopamine indicated a functional relationship ofOctopamine responsiveness to reproduction.

TL;DR: Corporal allata from adult and larval Diploptera punctata females were tested for sensitivity to inhibition of juvenile hormone synthesis by allatostatins in vitro and inhibition by all atostatin 1 was consistently high after larval and adult moults and thereafter changed with corpora allata activity.

TL;DR: Phytophagous insects evolutionarily adapted to feeding on nutrient-poor but allelochemical-rich host plants may have evolved biochemical/physiological mechanisms that serve to maintain effective enzyme function in the context of nutrient deficiency.

TL;DR: Larvae previously deprived of sugar in their diet subsequently showed a strong tendency to feed on a sugar diet if given a choice between a protein diet and a Sugar diet, but this tendency was abolished if trehalose was injected into the blood of sugar-deprived larvae.

TL;DR: Cutting the connectives behind the suboesophageal ganglion disinhibits chewing, so that continuous rhythmic mandibular movements occur even in the absence of mechano- or chemostimulation of the mouthparts.

TL;DR: Improvements in the purification of Galleria mellonella haemocytes using Percoll gradients are described and the presence of prophenoloxidase in the granular cell type alone indicates that this system may be involved in the haemocyte co-operation process.

TL;DR: A similar rapid increase in cold tolerance after a period of “acclimation” in an atmosphere of oxygen-free nitrogen is described, suggesting that this rapid but temporary increase incold hardiness is part of a generalized response to a range of factors which suppress metabolism, such as low temperature and anoxia.

TL;DR: Although D. melanogaster and D. simulans populations originating from a tropical site (Cairns) were less resistant to desiccation than conspecific populations from a temperate site (Melbourne), the populations had similar acclimation responses and there was no evidence for geographic variation in acclimated ability.

TL;DR: FTIR is useful for studies of spatial and temporal differences in cuticular lipids of arthropods and is applicable to either lipid extracts or lipids in situ (in cast skins or intact wings).

TL;DR: Application of a juvenile hormone analogue restored the ability of allatectomized females to produce female-specific polypeptides and to sequester them into the ovaries by means of ovariectomy and immunoblotting.

TL;DR: The present study does not imply that freeze tolerance is more efficient than freeze avoidance in promoting cold hardiness, and it is not necessary to say that freezing-tolerant beetles are more effective than freeze-avoiding beetles.

TL;DR: It is suggested that diapause in the parasitoid larvae is initiated by hormonal differences between these aphid morphs, independent of environmental cues and maternal effects.

TL;DR: Data suggest that an endogenous proctolin-like peptide in these arachnids may act as a cardioregulatory neuromodulator or as a neurotransmitter in the central nervous system.

TL;DR: It is concluded that acetylcholine release in the cockroach central nervous system is modulated by functional M 2 -like presynaptic receptors.

TL;DR: Exogenous cAMP, cAMP analogues and forskolin all stimulated fluid secretion by the isolated Malpighian tubules of Acheta domesticus, and consideration is given to the establishment of a convenient assay for diuretic peptides which stimulates adenylyl cyclase activity.

TL;DR: The data support the following hypothesis: when the tick exceeds the critical weight, ecdysteroids are released into the haemolymph, where they trigger salivary gland degeneration and the hormone also accumulates in the ovary where it may play a role in tick development and/or hatching.