摘要:

Abstract.Receptor neurones with high selectivity and sensitivity to plant odours were found within short sensilla trichodea on the antenna of both female and maleSpodoptera littoralis(Boisd.) (Lepidoptera: Noctuidae) by using single‐sensillum recording techniques. In 112 sensilla from females and forty‐one from males, twenty‐four different receptor neurone types were characterized according to their specificity. Altogether, twenty‐six plant and three sex pheromone compounds were tested. Receptor neurones responding with high specificity to flower odours, green leaf volatiles, oviposition deterrents and other general host plant odours were identified. In twenty‐one receptor neurone types, responses were elicited by one or several plant compounds, and in three types responses were elicited by sex pheromone compounds. The majority of the receptor neurones responded to only one or two of the tested compounds. In general, only one of the two receptor neurones in a sensillum responded to any of the compounds tested. An exception was a receptor neurone responding to plant odours (green leaf volatiles) and another receptor neurone responding to a sex pheromone compound ([Z]‐7‐dodecenyl (acetate), which occurred in the same sensillum. The majority of the receptor neurones displayed a high sensitivity to plant odours. No morphological difference was identified the different se

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1995.tb00001.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Abstract.The time‐course of behavioural change in response to crowding and re‐isolation was investigated in adults ofSchistocerca gregariaForskål (Orthoptera, Acrididae) using logistic regression analysis. Crowding solitary‐reared adults for a period of 4 h caused them to behave similarly to crowd‐reared insects, with their becoming much more active and moving towards rather than away from a stimulus group of locusts. Responsiveness to crowding was greatest in young adults. The behaviour acquired after 48 h of crowding was lost within 1 day of re‐isolation. Although experience by solitary‐reared adults of crowding for 48 h had only transitory effects on their own behaviour, there was also a long‐term influence on the behaviour of their offspring. The strength of this effect was dependent on the age at which adults experienced crowding, increasing in a graded manner with adult age, and hence the recency of crowding before oviposition. Parents crowded at a late stage in the reproductive cycle yielded hatchlings which behaved indistinguishably from those from crowd‐reared adults. Such an effect is consistent with the idea that females, through their previous experience of crowding, are effectively predicting the probability that their offspring will emerge into a high‐density population, and predisposing their hatchlings' beh

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1995.tb00002.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Abstract.Cohorts of adult femaleLucilia cuprinaWiedemann (Diptera: Calliphoridae) were fed a single 5 μl droplet of liver exudate after which half the females were allowed to mate and the other half left as virgins. Females were housed individually with water and sucrose for between 4 and 7 days after mating. Females were dissected to record the level of ovarian development and the size of their primary oocytes. Mating did not give protein‐limited females any significant nutritional benefit in terms of either increased oocyte development, yolk deposition or oocyte size. Hence, it is concluded that maleL.cuprinado not provide females at mating with any obvious material benefits beyond their spe

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1995.tb00003.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Abstract.Ovarian dissections were performed on the tsetse fliesGlossina morsitans morsitansWestwood andG.pallidipesAusten of known ages, maintained in the laboratory or on an island in Lake Kariba, Zimbabwe. The lengths (l2andlu) of the second largest oocyte and of the larvain uterowere found to increase approximately exponentially during pregnancy. The length (l1) of the largest oocyte increased exponentially for about the first 80% of pregnancy. Linear relationships between the log values ofl1,l2andluin field‐caught flies, of unknown chronological age, are consistent with the idea that growth patterns are similar in laboratory, island and open field situations. The egg phase takes upc.45% of pregnancy in both species, regardless of season and the absolute duration of pregnancy. The changes in the log values ofl1,l2andlu, over the ranges within which they change linearly, can be used to assign flies to their stage of pregnancy. When applied to field data the rule showed thatG.pallidipescaught in odour‐baited traps, and on a mobile electric net, exhibited major activity peaks shortly before and after parturition. Flies from the trap (but not the net) showed a smaller peak of activity near the middle of pregnancy. The egg and the three larval phasesin uterotake upc.45%, 25%, 20% and 10% of pregnancy respectiv

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1995.tb00004.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Abstract.A behavioural test was used to determine the light sensitivity of the nocturnal mosquitoAnopheles gambiaeGiles s.s. to low intensities of ‘white’ light (tungsten filament), ‘red’ light (white light filtered by a darkroom safelight filter) and ‘infra‐red’ light) of two types (white light filtered by a λ>700 nm filter, and light‐emitting diodes with λ>900 nm). Mosquitoes were placed in a 20 cm diameter flight‐tunnel and their ‘optomotor’ response to a pattern of stripes moving across their visual field (at 14.5 cm s‐1) was recorded with infra‐red‐sensitive video. In free‐flight, with ample light, the mosquitoes controlled their flight speed and direction in relation to the stripe movement, so that the stripes always appeared to move across their visual field from front to back. They did this by flying either with the moving stripes fast enough to overtake them (19.5 ± 0.7 cm s‐1), or against them more slowly (10.3 ± 0.7 cm s‐1)‐ The net ground speed of the mosquitoes was thusc.4–5 cm s‐1. This response was significant down to 10‐5W m‐2in ‘white’ light, and 10‐3W m‐2in ‘red’ light. At light intensities below threshold and in infra‐red light, however, they appeared to fly at random with respect to the stripe movement. The assumption commonly made, that mosq

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1995.tb00005.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Abstract.The effects of plume intermittency and volume on behavioural and flight responses to pheromone of maleCadra cautella(Walker) (Lepidoptera: Phycitinae) were investigated in a pulling wind tunnel. The fine‐scale structure of turbulent pheromone plumes was mimicked and manipulated using a pulser device that generated continuous ribbon plumes or intermittent plumes with defined pulse frequency and volume. As pulse frequency increased from 0.6 to 5 Hz and injected volume increased from 0.5 to 5 mls‐1, males flew progressively higher air and ground speeds, turned less frequently, and steered smaller course angles, resulting in straighter flight tracks. The faster the frequency of pulses and the greater the volume of the plume, the higher the proportion of males responding, the shorter their latencies, and the less time spent in the behaviour. Flight tracks of maleC.cautellato point sources of pheromone depend on the frequency of filaments encounte

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1995.tb00006.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Abstract.To disentangle cause and effect in previously observed relationships between fat content and flight activity in male tsetse (Glossinaspp.), three groups of flies were fed at different intervals to raise their fat content to different levels before their flight activity was recorded. The greater the mean daily blood intake, the higher the fat content and the greater the subsequent spontaneous flight activity, thereby using up almost all of the fat reserves before the next blood meal. It is proposed that although male flies would benefit from maximum food intake to permit maximum flight associated with mate‐seeking, they do not in fact feed as often as possible either in the field or the laboratory. This is explicable if energy acquisition is constrained by an additional mortality risk associated with feedin

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1995.tb00007.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Abstract.Diapause incidence, winter survival and triacylglycerol content were studied in temperate species ofDrosophilaby outdoor rearing in Sapporo (a cool‐temperate region), northern Japan. In strains ofD.subaurariaandD.triauraria(cool‐temperate species) from northern Japan, diapause was induced in adults having eclosed after early September, but in those having eclosed after mid October in strains ofD.rufaandD.lutescens(warm‐temperate species) from southern Japan. A subtropical strain ofD.triaurariadid not enter diapause. In the strains of cool‐temperate species from northern Japan, about 70% survived until spring when eclosed in mid autumn, whereas when eclosed earlier and later flies had a lower ability to overwinter. The warm‐temperate species and a subtropical strain ofD.triaurariaalso survived longer when eclosed in mid autumn than when eclosed later, but they were unable to survive until spring. The triacylglycerol content was higher in the cool‐temperate species from northern Japan than in the warm‐temperate species and a subtropical strain ofD.trauraria.In each species the triacylglycerol content of adults was higher when they eclosed in early and mid than in late autumn. It is assumed that triacylglycerol plays an important role in overwintering of theseDrosophilaspecies and the low triacylglycerol level is the primary cause of the low overwintering capacity of individuals eclosing i

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1995.tb00008.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Abstract.Recombinant inbred lines were produced from hybrids between diapausing and non‐diapausing strains ofDrosophila triaurariaBock&Wheeler by twenty generations of full‐sib mating. The analysis of these inbred lines suggests that the difference in the photoperiodic response between the original diapausing and non‐diapausing strains is due to genes at three or four loci and at least one of these loci is located on the X chromosome. The original diapausing strain and two inbred lines exhibited circadian peaks when subjected to the Nanda‐Hamner protocol, although they had different critical daylengths. This suggests that critical daylength is modified independently of the circadian oscillation system in this species. On the other hand, diapause duration was correlated with critical daylength among the inbred lines and the original diapausing strain, suggesting that these two traits are under the control of the same genetic

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1995.tb00009.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Abstract.The involvement of the endocrine system in courtship, mating, maternal behaviour and the gonadotrophic cycle was studied in the earwig,Euborellia annulipes, after application of JH III and, alternatively, precocene II.Topical application of 35 or 122 μg of JH III to newly eclosed females advanced the onset of courtship behaviour from 6.6 ± 1.3 days in acetone‐treated controls to 1.4 ± 2.8 and 0.5 ± 2.5 days, respectively. Application of 6 μg of JH III had no effect on the onset of courtship behaviour. Applications of Juvenile Hormone had no significant effect on the age at first mating nor on the duration of mating, though the trend is towards advanced onset. The age at first oviposition was advanced by hormone treatment; clutch size and the proportion of offspring hatching was reduced by hormone treatment. The interclutch interval, size and proportion hatching of the second clutch were not affected by hormone treatment.Topical application of 50 μg of JH III to females on the day of oviposition shortened the total duration of maternal care from 15.4 ± 0.5 to 5.3 ± 1.7 days; whereas in acetone‐treated and precocene II‐treated groups maternal care lasted 16.1 ± 1.9 and 13.8 ± 1.6 days, respectively. The duration of maternal care was positively correlated with number of offspring hatching and fledging.In a corollary experiment, topical application of JH III significantly enhanced the onset of the second gonadotrophic cycle as assessed by basal follicle length; application of 20 μg of precocene II, either singly or in repeated doses, did not delay growth of basal follicles. Finally, repeated application of as much as 80 μg of precocene II had no effect on basal follicle length, nor on ovary wet weights.These results are consistent with the hypothesis that intermediate to high titres of JH are associated with oocyte growth, mating, and the cessation of maternal care; low titres of JH appear to be associated with the period of maternal behaviour and slow ovarian fol

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1995.tb00010.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY