bluuebunny/crossref_metadata_2025 huggingface dataset:
Mode of inheritance of face fly diapause and its correlation with other developmental traits
Authors: KIM Y. , KRAFSUR E.S. , BAILEY T. B. , ZHAO SULING
Published: March 2008

Abstract.

Adult face flies, Musca autumnalis De Geer, respond to short photoperiods by entering diapause. Diapause responses to different photoperiods at a mean temperature of 17°C varied among seven laboratory face fly strains. Old strains lost much of their diapause responses.

To analyse the nature of diapause inheritance, hybrids and their back‐crosses were made between two strains that showed the greatest difference in diapause introduction at 10:14 h(L:D), and 17°C.

Responses of hybrids to the short photoperiod were intermediate to those of their parents. Joint scaling tests showed that diapause did not fit an additive model and the lack of fit was attributed to incomplete dominance. No cytoplasmic effect was detected, but diapause was partially sex linked.

Diapause heritabilities were 47% and 30% in the broad and narrow senses, respectively.

Estimates of the minimum number of diapause genes suggested a small number.

Developmental rates of egg to adult, ovarian follicle growth, and pterin accumulation were inversely correlated with diapause propensities, suggesting pleiotropy or linkage.
Discriminant conditioning of foragers in the Asian honey bees Apis cerana and A.dorsata
Authors: WELLS HARRINGTON , RATHORE RAM R. S.
Published: March 2008

Abstract.

Nectivore foraging environments are typically modelled as choices among non‐fluctuating rewards, but in reality they often consist of intermittent daily nectar and pollen sources. Intermittent rewards create two distinct foraging problems for colonial nectivores: re‐recruitment (periodically returning to intermittent rewards) and re‐allocation (finding new rewards).

The role of scent in learning and remembering the locations of discontinuous nectar rewards was examined by testing re‐recruitment efficiency of Apis cerana and A.dorsata to reward‐correlated scents (odour discriminant self‐conditioning). Experiments examined the responses of non‐naive foragers to an odour correlated with prior reward, and to odours not correlated with prior rewards, by placing different scents into a colony and observing the number of bees re‐recruited to a feeding station.

Re‐recruitment of non‐naive foragers in both species was significantly greater in response to the conditioning scent than to the experimental controls. However, species behaviour differed in one aspect; re‐recruited A.cerana foragers landed on the feeding station when unscented reward was offered, whereas re‐recruited A.dorsata foragers returned but would not land without conditioning scent present in the reward.
Acoustically‐orienting parasitoids in calling and silent males of the field cricket Teleogryllus oceanicus
Authors: ZUK MARLENE , SIMMONS LEIGH W. , ROTENBERRY JOHN T.
Published: March 2008

Abstract.

On three Hawaiian Islands, the introduced Australasian field cricket Teleogryllus oceanicus Le Guillou (Orthoptera: Gryllidae) was found to be attacked by the phonotactic parasitoid tachinid fly, Ormia ochracea Bigot.

Noncalling males occurred with callers in all locations, but silent males were more heavily parasitized than callers.

Body size was unrelated to both calling status and the likelihood of harbouring parasitoid larvae.

An experiment examining the likelihood of calling in the laboratory by males collected as silent or calling individuals showed no difference between the two classes of males, after accounting for parasitoid levels; males harbouring larvae were less likely to call.
Freeze‐protection of overwintering monarch butterflies in Mexico: critical role of the forest as a blanket and an umbrella
Authors: ANDERSON J. B. , BROWER L. P.
Published: March 2008

Abstract. 1. At their high‐altitude overwintering sites in Mexico, monarch butterflies frequently are subjected to sub‐zero°C temperatures during December‐March. Although monarchs have moderate supercooling ability, two ecological factors strongly influence their capacity to resist freezing: wetting and exposure to the clear night sky.

2. As shown in Fig. 2, 50% of a population of butterflies with water on their body surfaces freeze at warmer sub‐zero temperatures (‐4.2°C) compared to butterflies with no water on their bodies (‐7.7°C). 100% mortality occurs, respectively, at −7.7°C and −15°C.

3. Comparative measurements of rainfall within a large overwintering colony in Mexico indicated that the intact canopy acts as an umbrella that reduces butterfly wetting during winter storms.

4. Variable experimental exposure of butterflies to the clear night sky indicated that openings in the forest canopy increases radiational cooling and causes monarch body temperatures to drop as much as 4°C below ambient air temperature. Monarchs under dense cover had body temperatures approximately the same as the ambient air temperature, but more exposed individuals had body temperatures below ambient in direct proportion to the degree of exposure. Consequently, forest thinning increases the probability that the butterflies will freeze to death.

5. Whereas both wetting and exposure are increased by disturbance of the forest canopy, the interaction of these two factors exacerbates freezing mortality during winter storms: 50% of dry and unexposed butterflies froze at −8°C, whereas wetted and fully exposed butterflies froze at only −0.5°C.

6. Butterflies inside and on the bottom of the fir bough clusters are better protected from wetting than those on the outside. This supports the hypothesis that the structure of the butterfly clusters has evolved through individual selection to avoid wetting.

7. The data strongly reinforce previous evidence that forest thinning should be totally prevented within and adjacent to the overwintering sites in order to minimize both wetting and exposure of the butterflies that synergistically increase winter mortality at the overwintering sites in Mexico.
Magnetic resonance guided focused ultrasound surgery. Ablation of soft tissue at bone–muscle interface in a porcine model
Authors: Kopelman D. , Inbar Y. , Hanannel A. , Pfeffer R. M. , Dogadkin O. , Freundlich D. , Liberman B. , Catane R.
Published: March 2008

Background  Pain management treatments of patients with bone metastases have either efficacy problems or significant side effects. Percutaneous radiofrequency ablation has recently proved to be of palliative value. Magnetic resonance guided focused ultrasound surgery (MRgFUS) uses focused ultrasonic energy to non‐invasively create a heat‐coagulated lesion deep within the body in a controlled, accurate manner. The surgeon can monitor and control energy deposition in real time. This technology represents a potential treatment modality in oncological surgery. We investigated the ability of two MRgFUS methods to accurately and safely target and ablate soft tissue at its interface with bone.

Materials and methods  Heat‐ablated lesions were created by MRgFUS at the bone–muscle interface of 15 pigs. Two different methods of energy delivery were used. Temperature rise at the target adjacent to bone was monitored by real time MR thermal images. Results were evaluated by MRI (magnetic resonance imaging), nuclear scanning and by histopathological evaluation.

Results  Soft tissue lesion sizes by both methods were in the range of 1–2 cm in diameter. Targeting the focus ‘behind’ the bone, achieved the same result with a single sonication only. Follow up MRI and histopathological examination of all lesions showed focal damage at its interface with bone and localized damage to the outer cortex on the side closer to the targeted tissue. There was no damage to non‐targeted tissue.

Conclusion  MRgFUS by both energy deposition methods can be used to produce controlled well‐localized damage to soft tissue in close proximity to bone, with minimal collateral damage.
Classification of chronic kidney disease by estimated glomerular filtration rate
Authors: Marsik C. , Endler G. , Gulesserian T. , Wagner O. F. , Sunder‐Plassmann G.
Published: March 2008

Background  Serum creatinine concentration alone as a marker of kidney function is inadequate. Thus several equations for estimating glomerular filtration rate (eGFR) have been proposed within the last years.

Patients and methods  In our study we compared three frequently used equations, the abbreviated modification of diet in renal disease (MDRD) formula, the extended MDRD formula and the recently proposed Mayo clinic equation in a large patient cohort.

Results  A total of 244 507 patients attending the Vienna General Hospital were evaluated for their kidney function and three equations for eGFR were compared. The median age of the patients was 51 years (ranging from 18·0 to 102·6 years) with 44·3% males (n = 108 527).

We observed a significant increase of patients with eGFR classes four and five (according to Kidney Disease Outcomes Quality Initiative (K/DOQI) guidelines) with advanced age. Whereas approximately 1% of patients < 30 years presented with eGFR classes four and five (defined as eGFR < 30 mL min−1 1·73 m−2), this prevalence increased up to ∼12% in patients at the age of 80 years or older. All three equations showed comparable results for eGFR classes four and five. The proportion of patients with mild to moderate impairment of kidney function is higher using both MDRD equations.

Conclusions  The MDRD equations (particularly the abbreviated MDRD formula) result in considerably higher rates of eGFR classes two and three compared to the Mayo Clinic equation, while all three were comparable in classes four and five. This should be considered when eGFR is used in the diagnosis of chronic kidney disease.
Alterations of hepatic ATP homeostasis and respiratory chain during development of non‐alcoholic steatohepatitis in a rodent model
Authors: Serviddio G. , Bellanti F. , Tamborra R. , Rollo T. , Romano A. D. , Giudetti A. M. , Capitanio N. , Petrella A. , Vendemiale G. , Altomare E.
Published: March 2008

Background Mitochondrial dysfunction is considered a key player in non‐alcoholic steatohepatitis (NASH) but no data are available on the mitochondrial function and ATP homeostasis in the liver during NASH progression. In the present paper we evaluated the hepatic mitochondrial respiratory chain activity and ATP synthesis in a rodent model of NASH development.

Materials and methods Male Wistar rats fed a High Fat/Methionine‐Choline Deficient (MCD) diet to induce NASH or a control diet (SHAM), and sacrificed after 3, 7 and 11 weeks. The oxidative phosphorylation, the F0F1ATPase (ATP synthase) and the ATP content were assessed in liver mitochondria.

Results NASH mitochondria exhibited an increased rate of substrate oxidation at 3 weeks, which returned to below the normal level at 7 and 11 weeks, concomitantly with the coupling between the phosphorylation activity and the mitochondrial respiration (ADP/O). Uncoupling of NASH liver mitochondria did not allow the recovery of the maximal respiration rate at 7 and 11 weeks. The ATPase (ATP synthase) activity was similar in NASH and SHAM rats, but the mitochondrial ATP content was significantly lower in NASH livers.

Conclusions The loss of hepatic ATP stores is not dependent on the F0F1‐ATPase but resides in the respiratory chain. Dysfunction of both Complex I and II of the mitochondrial respiratory chain during NASH development implies a mitochondrial adaptive mechanism occurring in the early stages of NASH.
Broad host‐range effective mutants of Rhizobium fredii strains
Authors: Romero F. , Buendía‐Clavería A. , Ruiz‐Sainz J. E.
Published: March 2008

Rhizobium fredii strains USDA 192 and USDA 205 form nitrogen‐fixing nodules on Asiatic and different unbred soybean cultivars but are ineffective on American‐adapted soybeans. Further to our report on the isolation of spontaneous mutant derivatives of Rh. fredii strains USDA 192 and USDA 205 that were able to form nitrogen‐fixing nodules on the American soybean cultivars Wells and Fred, we show that the symbiotic properties of these mutants are very different from those of their parental strains. All the mutants effectively nodulated other American soybean cultivars different from that (Wells or Fred) used to select the mutants and they had also acquired the capacity to form nitrogen‐fixing nodules on Cajanus cajan and Macroptilium atropurpurcum. These results demonstrated that although Rh. fredii strains USDA 192 and USDA 205 are either completely ineffective or poorly effective on American soybean cultivars, C. cajan and M. atropurpureum, they have the inherent capacity to establish effective nitrogen‐fixing symbioses with these legumes. Transfer of the symbiotic plasmid of strain AB‐7 (a broad host‐range mutant derivative of USDA 192) to Rh. fredii strain SVQ‐127 (USDA192‐background) produced transconjugants that formed nitrogen‐fixing nodules on the American soybean cultivar Williams and M. atropurpureum. These results indicate that the mutation that produces the broad host‐range phenotype of mutant strain AB‐7 is located in its symbiotic plasmid. Rhizobium fredii strain USDA 192 was more competitive than its derivative AB‐7 to nodulate on the unbred soybean cultivar Malayan. Moreover, the presence of USDA 192 in the inocula severely inhibited nodulation on soybean cultivar Williams by the effective derivative AB‐7. Strain SVQ‐127 was able to nodulate effectively on the Asiatic soybean cultivar Peking although its symbiotic plasmid was no longer visible by agarose gel electrophoresis. DNA‐DNA hybridization experiments showed that the symbiotic plasmid, or part of it, was still present in the bacterial genome.
Specificity of an antiserum against Erwinia carotovora subsp. atroseptica in indirect ELISA
Authors: Jones D.A.C. , McLeod A. , Hyman L.J. , Pérombelon M.C.M.
Published: March 2008

Attempts to differentiate Erwinia carotovora subsp. atroseptica (Eca) from Erwinia carotovora subsp. carotovora (Ecc) by indirect ELISA using polyclonal antisera against the former bacterium were unsuccessful. However, when bacterial cells were preincubated with an antiserum against Eca serogroup I and excess serum washed away prior to coating on micro‐ELISA plates, specificity was improved. This modified indirect ELISA was able to separate Eca serogroups I, XVIII and XXII from all the Ecc serogroups tested. Cross adsorption of the antiserum with Ecc serogroup XXIX resulted in greatly reduced absorbance values for all strains/serogroups except Eca serogroups I and XXII. Cross adsorption with the homologous Eca strain reduced absorbance values for all strains/serogroups. It is suggested that the differentiation of Eca serogroups I and XXII obtained with the modified indirect ELISA could be attributed to the removal of antibodies cross reacting to soluble antigens and the retention of antibodies to specific cell surface antigens.
Potential problems in the use of oligonucleotide probes for staphylococcal enterotoxin genes
Authors: Okoji Christy N. , Inglis Barbara , Stewart P.R.
Published: March 2008

Oligonucleotide probes unique to the five major enterotoxin genes of Staphylococcus aureus were synthesized and used to detect DNA sequences homologous to these genes in 27 non‐clinical isolates of Staph. aureus isolated from nasal swabs of 74 healthy human volunteers. Genomic DNA from all 27 isolates reacted with at least one of the probes. In a phenotypic assay for toxin production by a reverse passive latex agglutination test however, only 15 of the 27 isolates produced enterotoxin in culture. The results raise the possibility that a number of Staph. aureus isolates harbour DNA sequences that are apparently silent or mutant copies of the enterotoxin genes. This complicates the identification of enterotoxin producers by tests which depend on oligonucleotide or DNA hybridization.
A note on lactobacilli and β‐glucuronidase activity in the intestinal contents of mice
Authors: McConnell M.A. , Tannock G.W.
Published: March 2008

A comparison was made of caecal β‐glucuronidase activity in the caecal contents of mice with or without lactobacilli as members of the normal microflora. Male mice that did not have lactobacilli as intestinal inhabitants had approximately 52% more caecal β‐glucuronidase activity than their female counterparts. Colonization of male mice by lactobacilli reduced the β‐glucuronidase activity to that of female mice.
The effects of transgalactosylated oligosaccharides on gut flora metabolism in rats associated with a human faecal microflora
Authors: Rowland I.R. , Tanaka R.
Published: March 2008

The effect on various caecal bacteria and their metabolic activities of feeding diet containing transgalactosylated oligosaccharides (TOS) with or without Bifidobacterium breve (administered in the drinking water) was investigated in rats colonized with a human faecal microflora. TOS (5% w/w in diet) or TOS plus B. breve, given for 4 weeks, induced increases in caecal concentration of total anaerobic bacteria, lactobacilli and bifidobacteria, and decreases in numbers of enterobacteria. Caecal pH was significantly reduced by feeding TOS, as were the activities of β‐glucuronidase and nitrate reductase. In contrast, β‐glucosidase activity was increased in TOS‐fed rats.

Dietary TOS was also associated with decreased conversion, by caecal contents, of the dietary carcinogen 2‐amino‐3‐methyl‐3H‐imidazo[4, 5‐f] quinoline (IQ) to its genotoxic 7‐hydroxy derivative.
l‐Arginine preferentially dilates stenotic segments of coronary arteries thereby increasing coronary flow
Authors: Lauer T. , Kleinbongard P. , Rath J. , Schulz R. , Kelm M. , Rassaf T.
Published: March 2008

Background and objectives.  Oxidized LDL cholesterol and cytokines increase arginase and decrease nitric oxide (NO) synthase expression in human endothelial cells, leading to a decrease in NO production. In arteriosclerotic plaques, characterized by increased oxidized LDL and cytokine levels, a sustained local NO reduction might enhance sensitivity of the downstream guanylyl cyclase system towards an acute NO increase. We tested whether application of the NO synthase substrate l‐arginine (l‐arg, 150 μmol min−1) or the NO donor isosorbide dinitrate (ISDN; 0.3 mg) preferentially dilates stenotic coronary artery segments (CS) subsequently increasing poststenotic coronary blood flow (CBF) in patients with coronary artery disease (CAD).

Design, setting and subjects.  Changes in coronary diameter and circumferential surface area were assessed by quantitative coronary angiography (QCA) in a nonstenotic upstream segment, the CS, downstream the CS and in a reference vessel (n = 24). CBF was estimated in a subset of 13 patients by QCA and intracoronary Doppler.

Results.  CS ranged from 62% to 89% (77 ± 5%). l‐arg increased minimal luminal diameter of the stenotic segment from 0.98 ± 0.06 to 1.14 ± 0.07 mm (P < 0.05) without affecting other coronary segments. Poststenotic CBF increased by 24 ± 3%. ISDN dilated all segments again with a predominance of CS (25 ± 4%) and increased poststenotic CBF by 38 ± 9%. In a multifactorial anova, a medication with an angiotensin‐converting enzyme inhibitor (decreasing inflammation and radical formation) and a ratio of LDL/HDL <3.5 were predictive for an l‐arg‐induced dilation.

Conclusion.  The increase in poststenotic CBF without affecting nondiseased arteries highlights the therapeutic potential of l‐arg in patients with CAD.
The role of pressure in controlling the entry of water into the developing eggs of the Australian plague locust Chortoicetes terminifera (Walker)
Authors: LEES A. D.
Published: March 2008

The normal internal hydrostatic pressure and the additional pressure necessary to rupture the egg shell was measured in the eggs of Chortoicetes terminifera, Newly laid white eggs burst at c 0.15 kg cm‐2, but after external tanning the chorion withstands c 0.5 kg cm‐2 when removed from its tanned foam ‘corset’ and 1.0 kg cm‐2 if left embedded in the egg pod material. Older eggs with formed cuticles often withstand 2.0 kg cm‐2 but yield at rather lower pressures if they develop ‘pin‐holes’. As the OP of the egg contents always exceeds 7.7 kg cm‐2 the rigidity of the wall is clearly insufficient to permit the generation of high hydrostatic pressures capable of preventing water entry during the non‐absorbing phases of development. Real hydrostatic pressures are lower than 0.06 kg cm‐2 in the young intact egg and reach only c 0.5 and 0.3 kg cm‐2, respectively, during the absorptive and post‐absorptive phases of development.

Several events contribute to the sigmoid form of the water uptake curve. Water is at first excluded by a permeability barrier associated with the chorion. Absorption is delayed until the yolk is completely enclosed by the serosal cell layer. After undergoing cleavage, the yolk is then rapidly mobilized to furnish precursors for cuticle synthesis; in consequence, the internal OP rises from δ 0.76d̀K to 0.93d̀K despite the massive inflow of water which is governed by the osmotic gradient. At blastokinesis the serosa becomes detached from the cuticle; cuticle deposition and yolk mobilization are halted, the OP falling rapidly to cδT 0.53d̀K. The bulk entry of water then ceases. Any excessive hydrostatic pressures which develop later are relieved by the formation of self‐sealing ‘pin‐holes’.
Proposal for a new term ‘echeme’ to replace ‘chirp’ in animal acoustics
Authors: BROUGHTON W. B.
Published: March 2008

The term ‘chirp’ as defined by Broughton (1952) and varied by him (1963a, b) is shown to be both inadequate and potentially misleading, particularly in the light of the principles of measurement of the time‐parameters of insect song, which are reviewed. It is important to include, in the measured duration of a given element, not only the durations of its constituent sub‐elements plus the intervals between them, but also an estimate of the interval that would have followed the last sub‐element, had the emission been prolonged further.

‘Chirp’ should be totally restricted to initial, empirical descriptions of sounds that appear undivided to the human ear (or ultrasonics of corresponding length). For a first‐order assemblage of syllables, the term ‘echeme’ with a highly relevant etymology, is proposed.

In early insect‐acoustics studies, Broughton (e.g. 1963a), seeking mainly to follow the admirable German terminology of Faber (e.g. 1953) and Jacobs (e.g. 1953), and to combine it with accepted physical terms, proposed certain English equivalents, many of which (such as ‘pulse’, ‘syllable’, ‘sequence’) have proved adequate in the years since then.

The term ‘chirp’, however, had been rather loosely and inappropriately used in still earlier studies (Broughton, 1952, 1953; Chavasse et al., 1954) as the equivalent of Jacobs' Silbe (syllable = sound or ultrasound corresponding to one stroke of the singing apparatus). This was in direct conflict with the dictionary usage of ‘chirp’ as a sound that appears unitary and undivided to the unaided human ear (M. Duijm, personal communication in 1962).

This is why, in the 1963 revision, Broughton abandoned the use of chirp as equivalent of Silbe, in favour of the direct translation, syllable; and proposed restricting ‘chirp’ to usage as a term for the first‐stage description of a unitary‐sounding element of an animal emission, regardless of its composition in terms of physical units (pulses) or physiological units (syllables). Thus, the song of Chorthippus brunneus (Thunberg)(Orth., Acrididae) sounds unitary to the human ear, but consists of a rapid series of sounds each corresponding to one stroke of the apparatus: it is therefore, according to the 1963 system, a ‘polysyllabic chirp’ (Fig. 1)‐a chirp that happens to be a first‐order assemblage of syllables. By contrast, the song of Chorthippus parallelus (Zetterstedt) is a clear series of unitary sounds each visibly produced by one movement, and is therefore a ‘sequence’ of ‘monosyllabic chirps’ (Fig. 2).
The aggregation of questing ticks, Rhipicephalus pulchellus, on grass stems, with observations on R.appendiculatus
Authors: BROWNING T. O.
Published: March 2008

Rhipicephalus pulchellus was observed to aggregate on the tips of grass stems in the field in Kenya. Laboratory studies of this behaviour, using simulated glass ‘stems’ in sand‐trays, showed that this aggregation was not due to responses to either (a) chemical marks placed on the stems by climbing ticks, or (b) other stimuli transmitted down the stems by ticks already at their tips. Instead, the aggregation on stems appeared to be an adventitious result of the ticks aggregating on the ground (in the lab., under filter paper covering the sand substrate of the apparatus) and then climbing the nearest stem in due course. Briefer, comparative observations on R. appendiculatus indicated that it was much more mobile on the stems, spending less time at their tips, and not obviously aggregating.
Initiation and maintenance of cocoon spinning behaviour by saturniid silkworms
Authors: LOUNIBOS L. P.
Published: March 2008

Larvae of Antheraea pernyi and Hyalophora cecropia terminate the feeding phase of the fifth instar by purging the alimentary tract. This occurs in the morning under artificial illumination schedules and precedes the initiation of spinning by a species‐specific time interval. Infusion of β‐ecdysone into H. cecropia late in the feeding phase may, under certain conditions, provoke premature gut purging or terminate spinning by causing premature metamorphosis. Experiments in which spinning A. pernyi were stripped of their cocoons at various stages of construction confirmed that caterpillars initiated the spinning of a second cocoon at the same point in the behavioural repertoire where they had been interrupted. The rapid turning involved in cocoon impregnation behaviour was executed only in the confines of a cocoon, and required that the hindgut be both distended by exudate and free to expel it. Severance of the ventral nerve cord anterior to the terminal ganglion also eliminated impregnation behaviour. Cyclic turning of the cat́erpillar in the cocoon persisted after spinneret occlusion or silk gland excision, but at a markedly depressed frequency.
A quantitative study of the grooming behaviour of the mymarid wasp Alaptus fusculus
Authors: CHEKE ROBERT A.
Published: March 2008

ABSTRACT. The grooming behaviour of Alaptus fusculus is described. Data on the frequencies of occurrence of seventeen different actions and their sequences were analysed. A single link cluster‐analysis of preceding‐following actions showed that in any bout of grooming the probabilities of actions by one leg being followed by actions initiated by the same leg (or its contralateral) are high. On the assumption that the behavioural sequences were Markovian, a vector of the species' ‘average behaviour’, in terms of relative frequencies of occurrence, was computed from transition probabilities. Further analysis, however, using indices derived from information theory shows that the behaviour has higher order dependencies; that is that an event is influenced by events further back in the sequence than the one immediately preceding it.
Motor responses to changes in the volume and pressure of the gas stores of a submerged water‐bug, Lethocerus cordofanus
Authors: MILLER P. L.
Published: March 2008

ABSTRACT. Electromyograms from the abdominal dorso‐ventral muscles of a freely swimming water‐bug, Lethocerus cordofanus Mayr (Belostomatidae), have shown that during a normal dive of c. 30 min duration there is a gradual rise in the frequency of tonic firing of slow motor axons which brings about a compression of the abdomen. This may help to offset a small, measured, negative pressure due mainly to nitrogen loss from the ventral hairpile which is thought to act as a physical gill. Towards the end of a dive, fast axons become tonically active and surfacing behaviour occurs. These responses can be experimentally manipulated by adding or extracting gases from the subalar store of a submerged bug. Similar responses have been obtained by subjecting a bug to high external pressures in a sealed vessel, and they suggest that a bug does not normally descend deeper than 5 m. It is also shown that either hypoxia or a reduction of store volume can initiate surfacing behaviour, although the latter is probably the normal stimulus for ascent. Muscular compression of the abdomen may help to prevent the inward leak of water into the store during a dive. It may also help to ensure the continuity of the lateral pathway between the ventral hairpile and the subalar store by slightly depressing the abdominal margins. The receptors controlling the motor response do not measure movements of an air—water interface, and they are probably internal proprioceptors, although their location is unknown.
The effect on Aphis fabae of diel changes in their food quality
Authors: CULL D. C. , EMDEN H. F. VAN
Published: March 2008

ABSTRACT. Marked diurnal changes in total soluble carbohydrates were found in broad bean leaves, with a maximum of c. 11% of dry weight at 18.00 hours to a minimum of c. 4% at 06.00 hours. If reflected in the phloem sap, this would mean that aphids receive different food from plants by night and by day. The growth rate of Aphis fabae was therefore compared on broad bean plants under light and darkness. Although the aphids showed the same mean gross growth rate under both conditions, those in the dark had a higher final percentage moisture content, their dry weight increase being negligible. Counts of honeydew droplets on a ‘honeydew clock’ indicated a reduction in excretion during the dark. Measurements of haemolymph concentration of Acyrthosiphon pisum were obtained by comparison of haemolymph vapour pressure with that of known sucrose solutions, using capillary tubes. Haemolymph samples collected at the end of the day showed a higher (mean 11.53 atm) and more variable osmotic pressure than those obtained at the end of the night (mean 8.62 atm). The more dilute sap in the plant at night may benefit the aphid by allowing it to compensate for osmotic stress incurred during daytime feeding. These results suggest that the diurnal change in total soluble carbohydrates in leaves of the broad bean is reflected in the phloem sap.
The sensitivity of larval Plodia interpunctella and Ephestia elutella (Lepidoptera) to light during the photoperiodic induction of diapause
Authors: BELL C. H.
Published: March 2008

ABSTRACT. The incidence of diapause in larvae of Plodia interpunctella and Ephestia elutella held under two light systems was examined. Both systems progressively shortened the photophase of 24‐h cycles, one with a motorized dimming switch providing dawns and dusks about 1 h long, the other switching the lights instantaneously. The mean critical photoperiod for P. interpunctella was about 131/4 h and for E. elutella just over 14 h. In both species light intensities as low as 0.2 lx influenced the induction of diapause. In P. interpunctella the critical photoperiod and sensitivity to light were similar at 23.±.;5°C and 20.5±0.5°C. At 22.5°C the percentage of diapausing larvae of E. elutella increased from 2% in long photoperiods (> 15 h light), to 100% in short photo‐periods (t 12.5h light). Fox P. interpunctella, at 22.5°C the percentage increased from zero in long photoperiods (> 14 h light) to about 98% in short photoperiods (< 11.5h light), and at 20°C from 12% to 100% over a similar photoperiodic range. Similar results were obtained under selected fixed photoperiods, switched on or off instantaneously.
Vitellogenin synthesis in the mosquito: the role of juvenile hormone in the development of responsiveness to ecdysone
Authors: FLANAGAN T. R. , HAGEDORN H. H.
Published: March 2008

ABSTRACT. Ecdysone stimulates the synthesis of vitellogenin in the fat body of mature female mosquitoes. Preparations from newly emerged animals, however, were found to be unresponsive to ecdysone. Responsiveness developed to a maximal level during a 36‐h post‐emergence period of maturation. This maturation could be accelerated with juvenile hormone application, prevented by allatectomy, and restored by corpora allata implants. It is concluded that the development of fat body responsiveness to ecdysone is dependent upon previous post‐emergence exposure to juvenile hormone.
Photoperiodism in the cabbage whitefly, Aleyrodes brassicae
Authors: IHEAGWAM EMMANUEL UCHE
Published: March 2008

ABSTRACT. Reproductive diapause was induced in A. brassicae by short photo‐period at 15 and 20°C but was almost prevented at 25°C. The critical photoperiod was LD 153/4: 81/4 at 15°C, giving 60% diapause. Photoperiodic sensitivity was confined to the early immature stages. Food plant quality appeared not to influence the induction or prevention of diapause. Chilling facilitated diapause termination. Overwintering females brought into the laboratory as adults or pupae from the field from September to December took longer before laying their first eggs than females collected in January and February.
Alterations of chemoreceptor function in army worm larvae (Spodoptera exempta) by a plant‐derived sesquiterpenoid and by sulfhydryl reagents
Authors: ARC WEI‐CHUN MA
Published: March 2008

ABSTRACT. Warburganal, a sesquiterpene dialdehyde from Warburgia sp., strongly suppressed the feeding response of Spodoptera exempta larvae to sucrose‐flavoured agar. Its effect on chemoreceptive sensilla of S. exempta was investigated. After a latent period (of up to an hour, depending on concentration), sensilla treated with warburganal produced transient bursting discharges in several receptor cells. Subsequently, receptor responses to sucrose or meso‐inositol were reversibly inhibited. These effects were abolished by mixing warburganal with cysteine or dithiothreitol (though not with other amino acids), and were qualitatively similar to the effects of the sulfhydryl reagents PCMB and NEM. The possible mode of action by which warburganal may act as an –SH acceptor and thereby affect energy transduction in the chemoreceptors is discussed.
Neurogenic pacemakers in the legs of Opiliones
Authors: MILLER P. L.
Published: March 2008

ABSTRACT. After autotomy, the legs of all the species of Opiliones examined, and of a Kenyan Pholcid spider, twitched spontaneously at the femoro‐patellar and tibio‐basitarsal joints, for periods of up to an hour. These joints lack extensor muscles, extension being achieved at the femoro‐patellar joint probably by haemolymph pressure, but at the tibio‐basitarsal joint of Opiliones by a cuticular spring which can extend the joint fully. Comparable twitching activity could be evoked without autotomy if the central nervous system was burnt, or by asphyxiation. Electromyograms from the femur or tibia of an isolated twitching leg showed regular motor bursts which accompanied flexions, and sensory activity during extension. Forced movements of the joints did not perturb the rhythm of the motor bursts. An isolated proximal half of a femur could still generate the same bursting pattern whereas no other region showed this activity after its isolation. Bursts recorded in the tibia were shown to be dependent on the integrity of the femur. By stimulation of the femur with 1 ‐ms current pulses it was possible to reset the rhythm. Stimulation with 1‐s pulses caused an acceleration or inhibition of the rhythm according to the direction of the current. Spontaneous bursts could be evoked in silent isolated legs, or in intact quiescent legs, by similar 1‐s current pulses. It is postulated that the femur contains independent neurogenic pacemakers which are activated by injury current from the damaged leg nerve; they produce regular bursts of motor impulses without the interplay of proprioceptive loops, and are responsible for the movements observed.
Sensitivity of an insect mechanoreceptor during moulting
Authors: GNATZY WERNER , TAUTZ JÜRGEN
Published: March 2008

ABSTRACT. The fine structure and the behavioural threshold for vibration sensitivity of the eight thoracic filiform hairs of Barathra brassicae caterpillars were investigated through an intermoult/moult cycle. Associated with each filiform hair is one bipolar sensory cell and three enveloping cells. The outer dendritic segment terminates in an ecdysial canal in the hair base and a tubular body lies at its distal end. Shortly before apolysis the dendrite elongates. By this means the connection between the sensory cell and the old cuticular apparatus is maintained while the epithelium and the old thoracic cuticle are separating. The new cuticular apparatus of the filiform hair is formed in the second half of the larval stage by the three enveloping cells. A second tubular body in the elongated outer dendritic segment is formed at the base of the replacement hair 10 h before next ecdysis, so that the new hair functions as soon as ecdysis is completed, the old cuticular apparatus with the old tubular bodies being torn away with the exuvia during ecdysis. Sensitivity to a 300 Hz tone was tested in the standing wave of a Kundt's tube. Throughout most of the larval instar the threshold was 2.0 ± 0.3 μm particle displacement amplitude until 1–2h before ecdysis when it rose to 6.8 ± 1.3 μm and at 10–30 min before the beginning of ecdysis no reaction to sound could be detected. Once the old cuticle was shed maximum sensitivity returned as soon as the replacement hairs were erect. The sensilla are therefore physiologically functional at all developmental stages except for 30–60 min during actual ecdysis.
Rhythmic activity of adult carrot fly, Psila rosae
Authors: WAINHOUSE D.
Published: March 2008

ABSTRACT. In a laboratory study of adult carrot fly activity, observations were made on caged populations and on individuals isolated in actographs. In cages in LD 12:12, feeding, oviposition, flight and possibly mating were all rhythmic. Peak feeding occurred within 1 h from lights‐on and peak oviposition and flight 10–12 h later. Mating frequency increased slightly in the latter half of the light phase. In actographs in LD 12:12, peak activity also occurred 10–12 h after lights‐on. Activity increased with age up to at least 5 days old, independently of the effects of starvation, and by day 5 males were approximately 3 times and females 8 times more active than on the day of emergence. Overall, males were approximately 1.4 times more active than females. Females isolated in actographs for 4 days in continuous dim light showed peaks of activity at intervals of approximately 22.5 h, and activity therefore appears to be a true circadian rhythm. In continuous bright light the activity of females became arrhythmic.
Directional cues in tactile stimuli involved in agonistic encounters in cockroaches
Authors: BELL WILLIAM J.
Published: March 2008

ABSTRACT. The ability of male cockroaches, Nauphoeta cinerea and Periplaneta americana, to respond directionally to tactile agonistic acts was tested using stimulation by artificially manipulated appendages. Responses by Nauphoeta included turning towards the stimulus at preferred angles of c. 40°, 90° and 180°, apparently relying on internally‐stored directional sensory information. This turning responsiveness depended in part on the social status of the receiving individual, since subordinate individuals often retreated or failed to respond. Periplaneta males reacted to tactile stimuli by quick movements away from the stimulus or by kicking towards it. The leg used in kicking was that nearest to the part of the body which was stimulated.
Food deprivation and the regulation of meal size in larvae of Chrysopa carnea
Authors: BOND ALAN B.
Published: March 2008

ABSTRACT. The course of repletion and the effects of food deprivation on meal size were explored in three experiments on larvae of Chrysopa carnea (Neuroptera). Feeding to repletion was found to occur within the first 30 min of exposure to food. Meal size increased as an ogival function of deprivation, up to the limit of gut capacity. Behavioural components involved in the initiation of feeding were little affected by deprivation and did not appear to be inhibited by distention of the gut. Termination of a meal may be mediated by the stimulation of prey‐release behaviour, rather than by inhibition of feeding.
The effect of photoperiod on the circadian rhythm of mating responsiveness in the fruit fly, Dacus tryoni
Authors: TYCHSEN PETER H.
Published: March 2008

ABSTRACT. The daily fluctuation in mating responsiveness of Dacus tryoni was recorded through a range of light cycles. Evidence was obtained of strict control of the fluctuation by a circadian clock. The phase setting of the fluctuation in the different light cycles was in conformity with Aschoff's (1965) generalizations about circadian rhythms, and had no relationship to overt sexual behaviour occurring during the cycles. The amplitude of the fluctuation in mating responsiveness varied between cycles, suggesting possible variation in the amplitude of the oscillation of the circadian clock.
The concepts of olfactory ‘arrestment’ and ‘attraction’
Authors: KENNEDY J. S.
Published: March 2008

ABSTRACT. The designation of pheromones and other odorous chemicals in terms of their unanalysed behavioural effects is a temporary convenience, but it perpetuates the use of portmanteau teleological terms and it focuses attention on chemical stimuli alone when in reality the observed reactions depend on central nervous integration of multiple inputs and outputs. Illustrative examples are given of ‘arrestment’ or the lack of it resulting from interaction between ortho‐ and klinokinetic reactions to odour; and of attraction resulting from interaction between non‐orienting odour cues and orienting cues from outside or inside the insect (‘allothetic’ or ‘idiothetic’, respectively). Longitudinal (as distinct from transverse) chemoklinotaxis, overlooked in a previous essay, is described; it does not appear to offer an alternative to odour‐modulated, optomotor anemotaxis as a mechanism for long‐distance guidance of flying insects to the source of a wind‐borne odour.
Gustatory mechanisms and sugar‐feeding in the mosquito, Culiseta inornata
Authors: PAPPAS LARRY G. , LARSEN JOSEPH R.
Published: March 2008

ABSTRACT. Gustatory hairs on the legs and mouthparts of the mosquito, Culiseta inornata, were stimulated with sucrose solutions to determine their role in the finding and consuming of nectar by females. Stimulation of tarsi initiated probing, which continued without subsequent stimulation of tarsal hairs. Turning in response to tarsal stimulation depended on which leg was stimulated. Once gustatory hairs on the labella were stimulated, turning and probing were discontinued. Stimulation of the hairs on the external surface of the labella apparently initiates the labellar opening response, while stimulation of hairs on the oral surface of the labella maintains the labellar response. Electrophysiologically recorded activity of cibarial and pharyngeal pumps was used to assess the influence of the five relevant sets of gustatory hairs on initiation of sucking. None of the sets alone were capable of initiating sucking. Sucking was initiated when the hairs on the oral surface of the labella were stimulated simultaneously with sensory hairs on the tip of the labrum. The gustatory hairs on the oral surface of the labella exerted considerable influence in determining the amount of sugar or water imbibed.
The control of circadian activity rhythms in tsetse flies: environment or physiological clock?
Authors: BRADY JOHN , CRUMP ANDREW J.
Published: March 2008

ABSTRACT. The typical V‐shaped pattern of biting activity that Glossina morsitans show in nature has been assumed to be due to environmental control (especially by temperature), but is now known also to be under control from an endogenous circadian clock. The relative importance of these two components was investigated (a) under constant conditions in actographs, and (b) by a re‐analysis of published field data. The actograph study reveals: (1) the length of flight bursts is the same at all phases of the rhythm; (2) the shape of the circadian V‐pattern changes with its amplitude, so that the less active a fly is, the more of its activity it performs in the morning; (3) both arms of the V respond to dawn as their principal zeitgeber; (4) high (35°C) and low (19°C) constant temperature reduce spontaneous activity level by c. 80%, and depress the evening arm of the V disproportionately. The analysis of the field data reveals: (1) the V occurs in nature independently of temperature; (2) biting activity is correlated positively with temperature in the morning and evening, but negatively through the middle of the day; (3) light directly influences the daily rhythm mainly by its effects at low intensity (the ‘photonegative reaction’ being a response to high temperature); (4) humidity has little influence on activity level. It is concluded that roughly 80% of the amplitude of the V‐pattern in the field is due to endogenous circadian control, and only 20% to direct control by temperature.
An analysis of anemotactic zigzagging flight in male moths stimulated by pheromone
Authors: MARSH D. , KENNEDY J. S. , LUDLOW A. R.
Published: March 2008

ABSTRACT. The zigzagging behaviour of male Plodia interpunctella flying up a plume of sex pheromone was investigated in a horizontal wind tunnel by detailed analysis of the moths' ground tracks, groundspeeds, orientations and airspeeds. The moths ‘homed in’ on the source of the pheromone plume by progressively reducing airspeed and turning more into wind, thereby reducing groundspeed and the distance between track reversals and so narrowing down their zigzags (Fig. 16). Track angles and times between reversals were unaffected. Removing the wind‐borne pheromone plume while a moth was flying along it confirmed that zigzagging can be an anemotactic response to losing the scent rather than a chemotactic response to the plume. For the first 1–2 s after the moth entered pheromone‐free air the zigzagging was indistinguishable from that shown when the plume remained; thereafter it widened progressively until the moths were flying to and fro at c. 90° to the wind. The after‐effect of odour stimulation persisted for many zigs and zags and many seconds (Figs. 4 and 5). Moths flying along pheromone plumes compensated efficiently for differences of wind speed, showing similar distributions of track angles to wind, and of ground‐speeds, in winds of 0.1, 0.2 and 0.3 ms‐1 (Figs. 12 and 13). Groundspeed varied with track angle to wind and this relationship was also similar in the three wind speeds (Fig. 14). This constancy of track angles and groundspeeds was due to the moths both increasing their airspeeds and turning more into wind at the higher wind speeds (Fig. 17). Thus the direction of the apparent movement of the ground pattern beneath the moths varied with wind speed. It is inferred that the moths, although unable to sense the wind directly, are able to compensate for changes in wind speed by integrating the wind‐dependent optomotor input with information about their own airspeed, or with information about their own turning movements. Maintaining some ‘preferred’ relationship between these inputs by adjustments of orientation and airspeed, would then serve to maintain a given combination of track angle and groundspeed independently of wind speed. The preferred relationship is repeatedly re‐set by the changing olfactory input from the pheromone plume, which also controls the switching between left and right of the upwind direction.
Synthesis of vitellogenins and diapause proteins by the fat body of Leptinotarsa, as a function of photoperiod
Authors: DORTLAND J. F.
Published: March 2008

ABSTRACT. During maturation of adult female Leptinotarsa decemlineata, synthesis of specific proteins by the fat body was investigated with the aid of in vitro incubations. Both vitellogenins and diapause proteins were present in all females. Under long days high rates of vitellogenin synthesis were observed, which were not reflected in the amount of vitellogenin present in the haemolymph. Under short days synthesis of three diapause proteins predominated. The highest rates of synthesis of these proteins occurred during the second half of the prediapause period. At the same time storage of two diapause proteins by the fat body was observed. Comparison of the synthesis of specific proteins in vivo and in vitro revealed the fat body as the main producer of haemolymph proteins.