摘要:

ABSTRACT.Individual stick insects were studied walking on a tread‐wheel. When a leg caught hold of a small fixed rod beside the wheel it: (a) applied a rhythmically modulated backward directed force (with the modulation frequency identical to the stepping frequency of the other legs); or (b) regularly lifted off the stick during the phase of minimum force, and then returned to the stick; or (c) it stepped onto the wheel. If the wheel was stopped, the applied force increased. It is deduced that this behaviour is driven by central rhythmicity of unknown origin. All the known sensory inputs to this behaviour are superimposed on this central oscillation. A hypothesis is discussed which qualitatively fits all the experimental results on the effect of these sensory influences on the timing of an individual leg's movements in stick insect

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1979.tb00195.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACT.The spontaneous locomotor activity of the larvae ofCuliseta incidenswas monitored with acoustic actographs. Individuals, in water resting on the cones of the speakers, displayed an activity rhythm in LD 12:12 with peak activity in the light phase. A similar rhythm occurred in DD following rearing in either LD 12:12 or LL, with free‐running periods of 23.5–24 h. No evidence was found of any consistent differences between the periods of the larvae and pupae. The amplitude of the pupal rhythm gradually increased as metamorphosis progressed. It is suggested that rhythmicity might also be found in those behavioural responses of mosquito larvae and pupae which have been the subject of previous stud

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1979.tb00196.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACT.In a horizontal wind tunnel,Drosophilaflew at almost constant height along tracks up to 2 m long. The flies rose or sank only slowly when it was so dark that they no longer responded to movements of the tunnel floor, suggesting that their height control is mediated, at least partly, by responses to their movement relative to the air. In the light, the flies maintained height better than in the dark and were very responsive to movements around them. They faithfully followed the up and down movements of horizon screens at their sides whether they were flying in still air or against a wind, even in the presence of many other stationary visual cues. The flies did not respond by compensatory height changes to real vertical movements of a patterned horizontal disc beneath them, nor to changes in the size of the floor pattern. They did respond to horizontal acceleration of the floor pattern in the direction opposite to their flight (optically simulating a descent by the fly), by an apparently compensatory increase in height, but they also rose (instead of sinking) in response to floor acceleration in the direction of their flight. When the floor was accelerated in either direction they showed compensatory groundspeed‐controlling responses. The increases in height might be alarm responses to sudden movements in the visual field beneath them. Both speed and height changing responses to floor movement were reduced when the number of stationary visual cues was increased.Drosophilathus control their height mainly by responses to the apparent movement of nearby visual cues at round about their own heigh

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1979.tb00197.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACT.Myrmica rubrasocieties were faced with intruders of the following species:M.rubra, M.sabuleti, Tetramorium caespitum, Lasius flavusandL.niger.The aggression of the resident workers was quantified by frequencies of mandible openings, seizings and gaster flexings. Intraspecific aggression was lower than interspecific, and it is suggested that this might be due to the polygynous behaviour ofM.rubra.There was no simple relationship between the intensity of aggression and the taxonomic remoteness of the intruder species. Differences in the levels of the aggressive response need to be better understood by analysis of the eco‐ethological interrelations of the species concerne

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1979.tb00198.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACT.l‐Glutamate when injected into the haemolymph ofLucilia sericatalarvae and adult maleLocusta migratoriawas rapidly removed by uptake mechanisms to other tissues in the insect. Data fromLucilialarvae indicate that following uptake glutamate is metabolized and the metabolites are secreted back into the haemolymph.l‐Aspartate injected into the haemolymph ofLucilialarvae was also rapidly removed. When bothl‐aspartate andl‐glutamate were injected simultaneously, the rate of glutamate removal was significantly reduced. It is concluded that glutamate and aspartate share the same uptake mechanisms.l‐Leucine injected intoLucilialarvae andLocustawas removed at a significantly slower rate than glutamate or

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1979.tb00199.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACT.Glutamate was detected in the haemoplasm of adult malePeriplaneta americana, adult maleSchistocerca gregaria, adult maleLocusta migratoria, larvalCalliphora erythrocephala, larvalLucilia sericataandCarcinus maenas, in all cases at low concentrations only, i.e. below 10‐5M. This was confirmed by high‐voltage paper electrophoresis and, in the case ofLucilia sericatalarvae, by the lack of pharmacological activity of the haemolymph. Glutamate was detected in appreciable concentrations in the haemocytes of all the arthropods analysed. It was found that levels of glutamine in the haemoplasm increased if the haemolymph had started to clot, if the haemolymph had been inadequately centrifuged, if the haemolymph was contaminated by other tissues and if acid protein precipitants were used which hydrolysed glutamine to glutamate. This finding removes a major argument against the acceptance ofl‐glutamate as a neuromuscular transm

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1979.tb00200.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACT.The effect of temperature on evoked activity in giant interneurons was compared inGrylloblattasp. (an alpine insect with a temperature preference close to 0°C) andAcheta domesticus.The response to sound and air‐puff stimulation of the abdominal cerci was monitored with extracellular electrodes placed under the ventral nerve cord. Responses to air puffs were elicited inGrylloblattawhile the animal was supercooled to ‐6°C. The supercooling point was reached and freezing occurred in the range ‐5.5 to 8.5°C. The upper extinction temperature could not be determined due to massive spontaneous giant fibre activity in the 12–15°C range masking responses to air puffs. Lethal heat coma occurred at 15–20°C, although most animals did not recover from the spontaneous CNS activity which preceded it. The extinction ranges forAchetagiant neurons were 3.5‐4.0°C and 42–44°C. Spike number peaked at 33–36 C and amplitude levels diminished as heat or cold coma was approached; ‐7.5 C was the mean supercooling point. Both species recovered from cold coma if supercooling was avoided; inAcheta, heat coma was also reversible. Giant fibre latencies inAchetadisplayed a Q10of 1.2 above 11–14°C, below which a break occurred in the curve and delays increased sharply. Latencies for the grylloblattid exhibited a Q10of 2 but no break in the curve was observed until 0° C was approached. Spike number and amplitude increased with temperature until spontaneous CNS activity obliterated responses to air puffs. The potential role of unsaturated fatty acids in low temperature adaptatio

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1979.tb00201.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACT.A comprehensive dose–response study of exogenous juvenile hormones, JHI and JHIII, on mating behaviour and on yellowing was carried out in allatectomized, crowded adultSchistocerca americana gregariamales. Injections of either hormone induced mating behaviour, but topical applications were almost completely ineffective. In contrast, topical applications were at least as effective as injections for inducing yellow colour. Induction and/or intensity of mating behaviour was dependent on the number of (repeated) administrations (from one to eight) and on the cumulative dose (80 or 160/μg) of the hormone, but these factors, within the above ranges, showed no distinct dose‐response relationship to yellowing. Even 160/μg of cumulative dose, given in the relatively most effective way (eight repeated injections of 20 /μg each), did not fully restore mating behaviour; the level of maximum intensity reached about half of that obtained for non‐allatectomized controls. JHI and JHIII did not differ markedly in this respect, but a 1:1 mixture of the two hormones improved the effect, revealing a mild synergy. JHI induced maximum or near maximum yellowing, but JHIII, under any conditions tested, was unable to induce full yellowing. The effect was always temporary; after cessation of JH administrations mating behaviour rapidly declined and the yellow colour slowly faded. The results indicate that the response of the two physiological systems (male mating behaviour and yellowing) to exogenous JH is completely independent. Although, depending on conditions of administration and on the kind of hormone, exogenous JHs were able to restore mating behaviour and yellowing, effective doses were extremely high. These conclusions are further d

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1979.tb00202.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACT.The circadian rhythm of pupal eclosion inSarcophaga argyrostomashows a declining responsiveness to the phase‐shifting effects of single light pulses as development proceeds, the intrapuparial stages becoming largely ‘insensitive’. Maximum responses occur in the intra‐uterine embryos and first‐instar larvae. Pharate adults, however, are responsive to single high temperature pulses. Pupae, pharate adults, and females carrying ovarian eggs, also respond to single stepwise transfers from light to dark, or vice versa, but the peaks of eclosion show a phase angle to the light which differs from that produced by transfers of embryos or larvae. The results are consistent with the view that separate ‘larval’ and ‘adult’ clocks occur at different stag

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1979.tb00203.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACT.Circadian rhythms are demonstrated in initiation and duration of copulation, and in ‘rocking’ by females during mating in the large milkweed bug,Oncopeltus fasciatus.In constant light or darkness there were no more than two or three recognizable cycles of any of these rhythms. In addition, light directly stimulated copulatory attempts, but did not influence their chance of success. Copulations were generally shorter during the early‐mid photophase and longer during the late photophase in LD 16:8, while initiations of copulation were fewest during the scotophase. The males were mainly responsible for these rhythms. It is suggested that the diurnal rhythm in copulation duration probably evolved as a consequence of the rhythms of flight activity and/or oviposition. Sperm from the late photophase matings typically displaced 90–100% of sperm from prior matings, while sperm from the shorter early photophase matings typically displaced less prior sperm. Peak rocking activity during mating occurred from 6 to 8 h after lights‐on in LD 16:8. Little rocking occurred during the late photophase, when the greatest percent of pairs arein copula.Feeding and drinking inhibited rocking activity, but the feeding rhythm did not drive the rocking rhythm. Rocking appears not to function in promoting termination of mating, positioning of the aedeagus, nor to mediate mechanical stimulation of egg production. Its function remain

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1979.tb00204.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY