摘要:

ABSTRACT.Adults ofOryzaephilus surinamensis(L.) (Coleoptera, Silvanidae) placed in an open arena containing a refuge showed a cyclic pattern of activity in light, dark (LD) cycles when food in the form of damaged wheat grains was placed in the arena outside the refuge. Placing food in the refuge reduced cyclic change and lowered the general activity of the beetles. Batches of fifty insects conditioned in LD 9:15 h or 15:9 h at25°C, 65% r.h., and transferred to continuous darkness (DD) at the end of a photophase, showed a circadian rhythm of foraging activity of periodicity near 24 h. Those transferred to continuous light at the end of a scotophase showed a 6 h delay in the onset of the next peak of activity, but subsequent peaks, although damped, revealed a periodicity near that in DD. The mean number of beetles wandering in the arena ranged from about eight in LD 15:9 h with all food in the refuge to about twenty‐one in LD 9:15 h with all food in the are

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1986.tb00384.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

ABSTRACT.Tritiated 10,11‐epoxyfarnesyl diazoacetate (EFDA), a photoaffinity label, can be covalently attached to the binding site of a JH‐III‐specific binding protein in the haemolymph ofLocusta migratoria migratorioides(R&F). The specificity of the binding of EFDA to the binding protein is verified by displacement with excess unlabelled JH‐III, and EFDA can be used to identify the binding protein in native pore‐limiting gradient poly(acrylamide) gel electrophoresis (PAGE) and sodium dodecyl sulphate‐PAGE. The native binding protein has a molecular weight of 575,000 and is composed of seemingly identical subunits of molecular weight 81,000.Three other high‐molecular weight serum proteins are identified by native PAGE: a lipophorin, composed of two kinds of apolipophorins, a larval storage protein and a cyanoprotein. The molecular weights and subunit structures of these proteins are investigated, but none of these other high‐molecular weight proteins bind JH‐III to an a

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1986.tb00385.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

ABSTRACT.The campaniform sensilla on the trochanter of the stick insect,Cuniculina impigraRedtenbacher, were stimulated by slightly bending the leg in the horizontal plane. Single sensory units in the nerve were recorded using glass microelectrodes. These units can be classified into tonic and phasic‐tonic receptors. In both cases there were units which increased their discharge frequency during forward movement of the femur, and units which responded to backward movement. No purely phasic receptors were foun

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1986.tb00386.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

ABSTRACT.The time course of dark adaptation inApis meliferaL. was investigated by analyses of phototactic behaviour and electroretinogram (ERG). The behavioural results give a function for dark adaptation showing that in the dark after strong light adaptation the sensitivity increases exponentially with a time constant of 3 min. The sensitivity changesc.2.4 log units during the time span of 5–720 s. The electrophysiological results indicate a smaller change in sensitivity at the level of the photoreceptors. Within a time span between 20 and 720 s the sensitivity increases during dark adaptation by a factor of 4.3 on a linear scal

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1986.tb00387.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

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 10‐2M), which are highly deterrent to the antMyrmica rubra.This compound is not at all or only slightly toxic to ants at 10‐2M. Compound 1, devoid of nitropropionate, is a minor constituent, and is neither deterrent nor toxic to ants.The fiveChrysomelaspecies studied andPhratora vitellinaealso sequester salicin in their eggs in amounts highly deterrent and toxic to ants. A singleChrysomelaegg 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 ofGastrophysa viridula, in contrast to previous reports on its presence in large quantities in the AmericanG. c

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1986.tb00388.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

ABSTRACT.Feeding behaviour of fifth instar tobacco hornworm caterpillars,Manduca sexta(Johansen) (Lepidoptera; Sphingidae), eating tobacco or artificial diet, is quantitatively described. The insects grow at the same rate on both foods. There is no daily rhythm of feeding behaviour. For most insects, feeding on either food occurs in bouts with the lengths of interfeed gaps and of feeding bouts appearing to be distributed randomly. However, in many insects there is a strong correlation between the length of a feeding period and that of the preceding non‐feeding period.The proportion of time spent feeding on tobacco is much greater than on artificial diet. On tobacco, feeding periods are separated by shorter interfeed gaps than on the artificial diet, while the rate of bout initiation is similar on either food.On both tobacco and artificial diet, the proportion of time spent feeding increases as the fifth stadium proceeds. This is due to both longer feeding bouts and shorter gaps. The rate of food acquisition within bouts does not change during the stadiu

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1986.tb00389.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

ABSTRACT.In mixed‐age cultures of the flesh‐fly,Sarcophaga argyrostoma(Robineau‐Desvoidy), the initiation of larval wandering (exodus behaviour) occurs as a gated circadian rhythm. In light‐dark (LD) cycles, most of this activity occurs in the dark, except in very short nights, or in certain phase relationships between the rhythm and light cycle. When transferred from series of LD cycles into continuous darkness (DD), cultures show a weakly persistent free‐running rhythm with a period of about 21 h. However, after transfer of first instar larvae from continuous light (LL) to DD, no such rhythm is observed. In contrast to larval exodus, formation of the puparia occurs at any stage of the LD cycle. The physiological mechanisms underlying this gated exodus behaviour, and its possible selective advantages, are

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1986.tb00390.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

ABSTRACT.Males ofGomphocerus rufusL. perform a courtship song consisting of repetitive units, each of which is composed of three subunits (S1, S2, S3). S1 is characterized mainly by slow and fast head rolling; S2 and S3 are distinguished by different types of leg‐stridulation. These movements and the associated sounds were recorded during presentation of visual stimuli, either linear displacement of a living female or optomotor stimuli generated by a striped drum. Females moved artificially through the binocular visual field of a courting male with a velocity of 1 cm/s or more are mounted by the male from any subunit S1, S2 or S3, although under natural conditions mounting occurs only from S2. Thus above a critical velocity the courtship programme can be modified. Rotation of a striped drum about the yaw axis of the male during the slow S1 induces asymmetrical leg position, following movements of the head, and prolongation of S1. During S2 the male is especially sensitive to optomotor stimuli and responds with marked changes in body position. In S3 the intensity of the song is reduced, and its duration shortened. Fast drum movements interrupt the courtship programme. Rotation of the drum about the roll axis elicits optomotor head turning that interferes with the head rolling of S1. The fast phase of S1 and the frequency of head‐rolling during S1 cannot be modified by optomotor stimulation. The results can be interpreted by assuming certain interactions between three central nervous elements: a calling‐song generator, a head‐rolling generator, and an optomotor

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1986.tb00391.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

ABSTRACT.InHolomelina lamaeFreeman daily eclosion of adults is gated, with males emerging before females. By advancing the onset of photophase and by delaying the onset of scotophase, it was demonstrated that lights‐on acts as the main phase‐setting cue for calling. Few females call on the day they eclose. Calling is initiatedc.9 h after the onset of photophase in 2‐day‐old females, and shifts to earlier times in older females. The duration of calling also increases with age. That calling is controlled by an endogenous circadian clock is indicated by its persistence in continuous light (LL) and dark (DD). In LL calling is dampened rapidly, but a single scotophase re‐entrains the rhythm. Decreases in temperature advance the onset of calling and the mean hour of calling, while increases in temperature delay both. However, the magnitudes of such phase‐shifts depended upon hour of the photoperiod. Moreover, cooling and heating appears to exert both transient and long‐term effects on the calling rhythm. An 8 h period at a reduced temperature in LL induces calling in females whose calling is dampened, and entrains the calling rhythm. Females maintained in DD from second instar larvae to the adult stage exhibit a circadian calling rhythm se

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1986.tb00392.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

ABSTRACT.Locomotor, feeding, drinking, and oxygen consumption rhythms in adult virginAcheta domesticusL. all appear to peak in the first half of the scotophase, be entrained cophasically by a LD 14:10 h cycle, have a lights‐off Zeitgeber and persist in LL with a πc.25 h for the locomotor rhythm andc.23 h for the oxygen consumption rhythm. There is no evidence of these rhythms in last instar larvae. The onset of the locomotor rhythm requires 3 days at 30°C but 5–7 days at 25–28°C after the final ecdysis in virgins, indicating a temperature related development of the locomotor rhythm. Oxygen consumption rhythms are lacking in 2‐day‐old virgins but present in 8‐day‐old virgins. Feeding rhythms can be recorded in virgins as young as 2 days (before locomotor rhythm developed). Both oxygen consumption and locomotor rhythms persist during starvation. The results suggest that a central brain oscillator drives both feeding and locomotor rhythms independently, but that the oxygen consumption rhythm is derived from the metabolic demands associated with t

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1986.tb00393.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY