摘要:

ABSTRACT.Five possible mechanisms involved in the disruption of phero‐mone‐mediated behaviour in the control of lepidopterous pests are discussed. The various techniques used in the field, laboratory investigations of such mechanisms, and possible limitations in the application of such studies, are revie

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1982.tb00310.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

ABSTRACT.Locomotor activity of individual blowflies,Phormia (=Protophormia) terraenovaeR.D. (Diptera, Calliphoridae), was recorded by means of running wheels made of Perspex (plexiglass). At various intervals after hatching, flies were placed in the wheel in continuous light (120 lx). The period of the free‐running rhythm was often shorter than 24 h initially, but lengthened later and stabilized after 15–20 days at values around or above 25 h. The mean period was independent of age in both sexes. Within a range from 2 to 2000lx the period did not depend in a systematic way on intensity of illumination; no activity could be recorded below 1

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1982.tb00311.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

ABSTRACT.The duration of diapause in larvae ofPlodia interpunctella(Hübner) (Lepidoptera, Pyralidae) was assessed at 20°C in LD 11:13. Mean times from hatch to pupation for diapausing larvae from different populations ranged from 88 to 236 days. Most non‐diapausing larvae pupated within 70 days at this temperature. Transferring diapausing larvae to 25°C and LD 9:15, or to 20°C and LD 15:9, 70 days after hatch reduced the subsequent mean time to pupation by 18–82% and 9–63% respectively. Only two population samples terminated diapause faster under LD 15:9 at 20°C than under LD 9:15 at 25°C. The mortality of diapausing larvae caused by 6‐ or 10‐week exposures at 5, 7.5 or 10°C was generally less than 25%. Hybrids produced from a reciprocal cross between a temperate and a tropical African stock survived well. For other stocks there was some correlation between survival and diapause intensity. The low temperature regime which resulted in the greatest shortening of pupation time after return to the conditions used to induce diapause, did not always coincide with the temperature permitting the best survival. Results, however, indicate that some individuals of all stocks but one from the tropics are likely to su

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1982.tb00312.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

ABSTRACT.The difference in ecdysteroid activity in short‐day (10‐h photo‐phase) and long‐day (16‐h photophase)Leptinotarsa decemlineataSay adults was characterized by high performance liquid chromatography, which revealed that for short‐day beetles ecdysterone and ecdysone are the major constituents of the free ecdysteroids, whereas in long‐day beetles products co‐migrating with 2‐deoxyecdysone and 2‐deoxyecdysterone are just as abundant. Ecdysteroids were detected (15 ng/ml) only in the haemolymph of females. Ligation experiments showed that the induction of the diapause syndrome by inactivation of the corpora allata or the brain not only resulted in the formation of the typical diapause proteins but also in an increase of the ecdysteroid activity. It is suggested that adult diapause inL.decemlineatais regulated by a mu

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1982.tb00313.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

ABSTRACT.In fourteen releases, most femaleD.radicum(L.) (Diptera, Anthomyiidae) flew upwind or at an angle to it of less than 77° regardless of the presence of host‐plant odour. Females ready to lay eggs flew upwind without prior stimulation by odours from either a host crop or a trap releasing up to 3 ml/day of the attractant allylisothiocyanate. Upwind flight was more pronounced in flies from a diapause than from a continuous, non‐diapause culture. Males from the non‐diapause culture dispersed upwind and downwind in more or less equal numbers; old males flew mainly downwind. But, like the females, most males from the diapause culture flew upwind. Long‐distance, odour‐modulated anemotaxis did not appear to be used to locate distant host crops by either sex. It is concluded that the distances of insect orientation to plant odours recorded to date are only of intermediate range, and that long‐range orientation to the odours of a host‐plant still has to be proven. It is suggested that host‐plant volatiles are involved not only in the final stage of host location but also in the first, and probably most important stage of host selection whilst the insect is

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1982.tb00314.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

ABSTRACT.Immediately after visiting cells containing immature queens, workers ofApis melliferaL. were observed to engage in prolonged cleaning, particularly of their tongues when they had visited larvae, and of their antennae when they had visited pupae. Thereafter other workers usually initiated and made antennal contacts with them. During such antennal contact the bee that had visited the queen larva often donated food. The implication of these findings on the distribution of pheromone produced by immature queens is discussed. Workers were stimulated to make antennal contact with the excised heads of bees from a queen's court, providing further evidence that queen pheromone is transferred between workers' antennae.

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1982.tb00315.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

ABSTRACT.This artificial selection study with the flesh fly,Sarcophaga bullataParker, tested the hypothesis that phenotypic variability in the length of the larval stage (under non‐diapause conditions) is largely a consequence of genetic variability. Selection for late pupariation resulted in a line that pupariated significantly later and also developed more slowly during other stages of the life cycle. In a diapause‐inducing environment, the selected line pupariated later, showed a higher incidence of pupal diapause, and remained in diapause longer than the unselected line. This is the first experimental evidence inS.bullatato show that diapause incidence and duration are related. The relationship between developmental rate and diapause traits may stem from the pleiotropic effects of genes associated with late pupariation, or from one or more genes associated with late pupariation being closely linked to genes that affect diapa

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1982.tb00316.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

ABSTRACT.Four groups of campaniform sensilla are found on the trochanter ofCuniculina impigraTedtenbacher (Phasmidae). One of these groups can be divided into two sub‐groups. The sensilla are approximately parallel within each group or sub‐group. As sensilla with parallel orientation will respond to the same direction of shear force, each group or sub‐group of campaniform sensilla should act as one unit. When the coxa is fixed, activity in the nerve supplying the campaniform sensilla can be released by bending the femur forwards and backwards. The sensilla are sensitive to movement only in one direction. The investigated sensilla react to the stimulus with phasic‐tonic discharge patterns. The dependence of the phasic component upon the velocity of the stimulus can be described by a power function. The tonic component depends on the amplitude of the stimulus. By mechanical stimulation of individual groups of sensilla it can be shown that at least two groups of campaniform sensilla contain units which respond to bending the femur backwards. The activity of some motor neurones can be influenced by slightly bending the leg in the horizontal plane. The levator trochanteris muscle is activated when the femur is bent forwards, and the frequency of the slow extensor tibiae motor neurone is increased when the femur is bent backwards. The reaction of both muscles is phasic. There is no detectable reaction in the protractor or the retractor of the coxa or the depressor troch

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1982.tb00317.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

ABSTRACT.Male oriental fruit moths,Grapholitha molesta(Busck) (Tortricidae), flew at lower overall and net ground velocities when they flew toward higher concentration pheromone sources. Turning frequency was greater with increased pheromone concentration, while the distance of turns from the plume axis back towards the axis decreased. Turning magnitude and inter‐reversal track angles remained constant at all concentrations tested. Concomitant with the changes in ground velocity but constant inter‐reversal angles, were decreases in airspeed, decreases in the moths' course angles and increases in their drift angles. The significance of these changes is discussed in relation to their possible role in a longitudinal chemoklinotactic programme of turning operating in conjunction with anemotaxis to allow location of a pheromone source in w

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1982.tb00318.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

ABSTRACT.The flight of maleSpodoptera littoralis(Boisd.) (Noctuidae) towards a pheromone source was recorded during the early part of the night using a cine camera and an image intensifier. The cine films were analysed frame by frame to produce flight tracks from which it was possible to calculate the mean advance rate of moths towards the pheromone source and their projected ground speed, for a series of positions downwind of the source. As wind speed was measured the moth's air speed was also estimated. The moths compensated for changes in wind speed by varying their air speed, hence maintaining a ground speed independent of wind speed. The ground speed itself was found to decrease as moths flew closer to the pheromone source.

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1982.tb00319.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY