bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemical defence in chrysomelid eggs and neonate larvae
Authors: PASTEELS J. M. , DALOZE D. , ROWELL‐RAHIER M. 
Published: March 2008

ABSTRACT. Eggs and neonate larvae of chrysomelid beetles (sub‐tribes Chrysomelina and Phyllodectina) were investigated for the presence of defensive substances.The two isoxazolinone glucosides (compounds 1 and 2), characteristic of the adult defence secretion, were detected in the eggs of all studied species. Compound 2, containing a nitropropionate, is always present in concentrations (above 10‐2 M), which are highly deterrent to the ant Myrmica rubra. This compound is not at all or only slightly toxic to ants at 10‐2 M. Compound 1, devoid of nitropropionate, is a minor constituent, and is neither deterrent nor toxic to ants.The five Chrysomela species studied and Phratora vitellinae also sequester salicin in their eggs in amounts highly deterrent and toxic to ants. A single Chrysomela egg often contains enough salicin to kill an ant. While the isoxazolinones are discarded with the egg shells, salicin is used by neonate larvae as a precursor for the production of salicylaldehyde in the thoracic defence glands, already functional at hatching. No salicin could be detected in the eggs of those species whose larvae produce cyclopentanoid monoterpenes, even if they feed on Salicaceae. No larva of any species seems to be able to produce detectable amounts of monoterpenes at birth. A very early defence, possible only in those species using salicin as the precursor for their defensive secretion, could be highly advantageous in protecting the clustered larvae during the long process of hatching and in avoiding cannibalism between siblings.Only trace amounts of oleic acid were found in the eggs of Gastrophysa viridula, in contrast to previous reports on its presence in large quantities in the American G. cyanea.
The influence of a shortage of hosts on the specificity of oviposition behaviour in species of Dacus (Diptera, Tephritidae)
Authors: FITT GARY P. 
Published: March 2008

ABSTRACT. When deprived of their preferred hosts for up to 16 days prior to behaviour assays, three relatively specialized tephritid flies, D. cacuminatus (Hering), D. cucumis French and D. jarvisi (Tryon), retain strong preferences for their particular hosts. Moreover, in the absence of the preferred hosts, D. cacuminatus, and to a lesser extent D. cucumis, will not accept fruits that are outside their normal host range. D. jarvisi readily accepts other fruits in the absence of its preferred host, Planchonia careya, but in common with the other two shows no increase in the number of eggs laid with increasing periods of deprivation. None of these species accumulate oocytes when deprived of fruits.In contrast, the highly polyphagous D. tryoni Frogg. lays more eggs and oviposits readily into a previously unacceptable fruit after 4 days without access to hosts. This change in behaviour is associated with a marked increase in the number of mature eggs carried by females.These results suggest an important difference between the generalist and more specialized species in the physiological control of oocyte maturation. In D. tryoni there appears to be no inhibition of oocyte development once the primary follicle has matured, whereas in the other species each ovariole contains no more than one mature egg.In D. tryoni, the change in behaviour which accompanies this increase in egg load, may influence its propensity to accept unusual fruits, and may help to explain its rapid acceptance of most cultivated fruits introduced to Australia.
Elucidation of the primary structures of the cockroach hyperglycaemic hormones I and II using enzymatic techniques and gas‐phase sequencing
Authors: SIEGERT KARL J. , MORDUE WILLIAM 
Published: March 2008

ABSTRACT. Two peptides, HGHI and HGHII, both inducing hyperglycaemia and activation of fat body glycogen phosphorylase can be isolated from the corpora cardiaca of the American cockroach, Periplaneta americana, using high‐performance liquid chromatography. Both peptides are N‐terminally blocked by a pyroglutamate residue and are thus not available for sequencing methods using the Edman degradation as this technique requires a free N‐terminus. The blocked peptides were treated with pyroglutamate aminopeptidase to cleave the pyroglutamate residue, and the C‐terminus of each peptide is also blocked and neither molecule can be cleaved by carboxypeptidase A. The following sequences for hyperglycaemic hormones HGHI and HGHII have been revealed using gas‐phase sequencing.HGHI pGlu‐Val‐Asn‐Phe‐Ser‐Pro‐Asn‐Trp‐NH2HGHII pGlu‐Leu‐Thr‐Phe‐Thr‐Pro‐Asn‐Trp‐NH2Both peptides show remarkable similarities to locust adipokinetic hormones I and II and prawn red‐pigment concentrating hormone, and are identical to two myotropic peptides MI and MII (O'Shea et al., 1984; Witten et al., 1984) and two cardioactive and hyperglycaemic peptides CC‐1 and CC‐2 (Scarborough et al., 1984), respectively, also isolated from the corpora cardiaca of P. americana.
The importance of daylength and queens for larval care by young workers of the ant Myrmica rubra L.
Authors: BRIAN M. V. 
Published: March 2008

ABSTRACT. Workers whilst still less than a month from emergence rear early stage larvae better in a 16h day than in one of 14h. The callows must perceive the diel rhythm directly because there are no foragers to give them a clue, and the larvae are kept in the dark and cannot respond directly. This, and the study of egg‐laying by young workers that preceded it, indicates that the extra hours daylight enable the workers to avoid the reproductive diapause that normally prepares them for hibernation. They retain active ovaries, ingest and share food with larvae either as trophic eggs or as a regurgitate from the crop.In late summer, callows can rear sexual larvae in spring condition. Queens have a small negative effect on this, expressed as a smaller, though still gyne, pupa produced a little earlier. This weak response to queens develops into a strong negative one at a constant temperature of either 10 or 20°C. The workers then behave as they normally do in spring, and feed a watery regurgitate (dietary control) or, if this fails to arrest sexual development, physically harass the larvae by biting them in the ventral thorax (manipulative control). Large workers then result instead of gynes.
Assisting components within a resistance reflex of the stick insect, Cuniculina impigra
Authors: BÄSSLER U. , HOFMANN T. , SCHUCH U. 
Published: March 2008

ABSTRACT. Rapid relaxation (shortening) of the femoral chordotonal organ in Cuniculina impigra Redtenbacher induces a depolarization followed by hyperpolarization of the fast and slow extensor tibiae motor neurons (FETi and SETi). The initial depolarization is caused by acceleration‐sensitive units of the chordotonal organ. The reverse sequence of responses is induced in flexor motor neurons. The common inhibitor neuron (CI) is depolarized by both lengthening (stretch) and relaxation of the chordotonal organ.The initial depolarization of FETi and SETi and the initial hyperpolarization of flexor motor neurons produced by rapid relaxation of the chordotonal organ and the depolarization of CI produced by lengthening of the chordotonal organ all oppose the resistance reflex response. However, these assisting components are weak compared to the resisting ones.
A direct search approach to characterize the sex pheromone composition giving maximal male response
Authors: DE JONG MART C. M. 
Published: March 2008

ABSTRACT. Response of male moths to sex pheromones differs markedly depending on blend composition. Natural selection can therefore be expected to favour males responding maximally to the blend produced by most females in the population. Thus it is relevant to quantify male response by the blend to which the males of a population respond maximally.To do this, wind tunnel experiments were carried out where males were observed while responding to blends of synthetic compounds emitted from rubber septa. By stepwise improvement it was shown that the blend to which Yponomeuta cagnagellus responds maximally comprises (Z)11‐tetradecenyl acetate (Z11‐14Ac), (E)11‐tetradecenyl acetate (E11‐14Ac), (Z)11‐tetradecenol (Z11‐140H), and tetradecyl acetate (14Ac) in the ratio 100(=50μg):1.5:20:45.The innovate aspects of the method used to obtain this result, are the use of a direct search approach as an integral part of the experimental procedure and the use of a summary variable to characterize male response. These aspects are discussed using the data on the response of Y. cagnagellus males.
Processing of calling songs by an L‐shaped neuron in the prothoracic ganglion of the female cricket, Acheta domesticus
Authors: STOUT J. F. , DEHAAN C. H. , HALL J. C. , RHODES M. 
Published: March 2008

ABSTRACT. An L‐shaped auditory intemeuron (LI) has been recorded from extracellularly and intracellularly, and identified morphologically (by Lucifer yellow or cobalt injection) in the prothoracic ganglion of mature female Acheta domesticus.The morphology of the LI is very similar to ascending, prothoracic acoustic interneurons that are most sensitive to higher carrier frequencies in both A. domesticus and other gryllid species. Its terminations in the brain are similar to ascending acoustic interneurons found in other gryllids. The LI neuron is most sensitive to 4–5 kHz model calling songs (CSs), the main carrier frequency of the natural call. Thresholds to high frequencies (8–15 kHz) are 15–20 dB higher.Increasing CS intensities of up to 15 dB above threshold at 4–5 kHz result in increased firing rates by the LI. More than 15 dB increase in intensity causes saturation with little increase in spiking rate until the intensity surpasses 80 dB. In response to 70 dB or higher stimulus intensities, the LI responds to the second and third CS syllables with one or two spikes, pauses, and then produces a burst of nerve impulses with the same or greater latency than for lower intensity stimuli. In response to CS syllables of changing duration (10–30 ms) this neuron responds with a rather constant duration burst of impulses. Syllable periods of the CS stimuli were accurately encoded by the LI.Progressively stronger injection of hyperpolarizing current reduces, and ultimately stops spiking of the LI in response to CS stimuli. More intense stimulation with reduced hyperpolarization shows an initial spike, pause and burst of spikes. Intracellular recording from axonal regions of the neuron shows large spikes, small EPSPs and a developing hyperpolarization through the response to a CS chirp. Inhibitory input to the LI is demonstrated at 4.5, 8 and 16 kHz. This probably explains the specialized response characteristics of the LI which enhanced its encoding of CS syllable period.
Stimulation of fluid secretion by single isolated Malpighian tubules of the house cricket, Acheta domesticus
Authors: COAST G. M. 
Published: March 2008

Abstract. Fluid secretion by single isolated Malpighian tubules of Acheta domesticus(L.) is stimulated by aqueous extracts of nervous and neuroendocrine tissues from the cricket. Diuretic activity, expressed as the increase in rate of secretion per microgram tissue protein (pl/mm/min/ug protein), is highest in the CA and CC.The response to aqueous CC extracts is dose‐dependent. The maximum increase in secretion rate is 300–350 pl/mm/min and the EDmax and ED50 are 0.1–0.2 and 0.02–0.03 gland pairs respectively.The diuretic activity in the CC is retained after 5min at 95C, and is freely soluble in 80% methanol. Diuretic activity is, however, greatly reduced after prolonged heating or after treatment with either pronase or chymotrypsin. It is conluded that the diuretic factor(s) is a low molecular weight peptide. A loss of activity after incubation with pyroglutamate amino peptidase suggests that some active peptides present are N‐terminally blocked.The diuretic activity of crude aqueous CC extracts is rapidly lost on standing at room temperature. This is partly prevented by precipitation of protein enzymes by either heat treatment or extraction in methanol.Synthetic vertebrate and insect neuropeptides are generally low in activity increasing fluid secretion by no more than 60pl/mm/min. However, extracts of neuroendocrine tissues from a wide range of insect species are potent stimulants of tubule secretion. Various biogenic amines were tested and have little effect on fluid secretion; thus they cannot contribute greatly to the response of cricket tubules to aqueous tissue extracts.
Visual responses of flying aphids and their chemical modification
Authors: HARDIE JIM , POPPY GUY M. , DAVID C. T. 
Published: March 2008

Abstract. Five winged forms of the black bean aphid, Aphis fabae, were subjected to 30 min of free flight in a recently designed, automated wind tunnel (David & Hardie, 1988). A circular green target, on the side of the chamber, was illuminated for 2.5 s of each minute of flight. Half of the fundatrigeniae (‘spring migrants’) and all of the virginoparous ‘summer migrants’ responded by flying towards the illuminated target while gynoparae (‘autumn migrants’) induced by short days over two generations in uncrowded conditions were unresponsive. 27% of generation 1 gynoparae, induced by crowded conditions and short days over one generation, responded to the target as did 50% of males.Anaesthetization of adult gynoparae with nitrogen and carbon dioxide, but not ether, induced targeted flights. However, the effect of carbon dioxide was transient over the first 10 min whereas the effect of nitrogen continued throughout the 30‐min experimental period. In addition, treatment of late fourth instar larvae, but not young adults, with Juvenile Hormone I provoked target responses. The results are discussed with reference to settling behaviour and the endocrine control of polyphenism.
Factors influencing dominance behaviour in queenless bumblebee workers (Bombus terrestris)
Authors: DOORN ADRIAAN VAN 
Published: March 2008

ABSTRACT. The establishment of a dominance order within seventy eight groups of four callow workers was investigated. The dominant worker establishes its position by means of overt aggression. Aggression starts 20—40 h after confinement. Dominance order becomes established within 2 days of removal from the colony. Once established, the dominance order is maintained by dominant‐subordinate interactions.The dominant worker starts ovipositing at an age of about 6 days. Subordinates rarely lay eggs. In 25% of the groups the dominant worker is superseded by another worker before any oviposition occurs. Once the dominance order is established, the dominant worker inhibits endocrine activity in subordinates.Differences in body size and in endocrine activity are thought to be responsible for the ranking of workers in the dominance hierarchy. Ranking seems to depend more on the activity of the corpora allata (CA) than on the activity of the ovaries. Ovariectomized workers do not differ from control workers in the performance of dominance behaviour. Dominant ovariectomized workers do not construct egg cells, but they do defend these if they are present.
Juvenile Hormone biosynthesis and release during oocyte development in Phormia regina Meigen
Authors: ZOU B.‐X. , YIN C.‐M. , Jr J. G. STOFFOLANO , TOBE S. S. 
Published: March 2008

AbstractA radiochemical assay for Juvenile Hormone (JH) biosynthesis and release by the corpus allatum (CA) was used to assess the effects of diet on CA activity of adult female Phormia regina (Meigen) fed either sugar‐water or sugar‐water‐liver. CC‐CA complexes were incubated in L‐methionine‐free medium 199 supplemented with 3H‐L‐methionine.The rate of JH release by the CC‐CA complexes is linear for 3 h and declines slightly thereafter. JH III appears to be one of the major components of the isooctane‐extractable product from incubated CC‐CA. High pressure liquid chromatographic analysis indicates that 10% of the released radiolabelled product is JH III. Rates of JH release show a strict dependence on L‐methionine concentration in the incubation medium, with optimal rates occurring between 100 and 150 μM L‐methionine. JH release is at a low level (<0.02pmolh‐1 per pair of CC‐CA) in flies fed only sugar‐water, but increases dramatically in flies fed sugar‐water‐liver (average release rate of 0.2pmolh‐1 per pair of CA, 24h after a liver meal). The rate of JH release increases steadily to more than 1.2pmolh‐1 per pair at 128h of age (i.e. 56h after a liver meal) at which time oocytes are mature. Elevated rates of JH release in vitro appear to be correlated in vivo with the appearance of vitellogenin in the haemolymph and its uptake by the developing oocytes.
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.
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.
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.