摘要:

Abstract.The antennal morphology ofPsylliodes chrysocephalaL. (Coleoptera: Chrysomelidae), an important pest of oilseed rape (Brassica napus), was studied. Two types of tricellular, integumentary glands were found. The common antennal glands are distributed under all sensilla‐bearing parts of male and female antennae. The male‐specific antennal glands are only located under a glabrous area found on antennomeres 6–10 of male beetles. The common antennal glands are synthetically active in both pre‐ and post‐diapause adults, but the male specific antennal glands are only active in post‐diapause (reproductively active) males. During studies of mating behaviour, the antennae of the males were highly active at the beginning and end of copulation, and in response to increased female activity. The male specific antennal glands may secrete a sex pheromone, and the glabrous area on the male antennae could be the release site for such

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1994.tb01048.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract.Electrophysiological, behavioural and field evidence is presented for a volatile attractant produced by host‐seeking, parous femaleCulicoides impunctatusGoetghebuer. Attraction of host‐seeking females to other live parous females or to extracts of parous females was demonstrated in Y‐tube bioassays, as well as in field trials using baited sticky traps. Threshold numbers were 100–200 females, both in the laboratory and field. Antennal receptors to this pheromone were revealed by recording electroantennograms (EAGs) in response to odour from live parous females and to the extracts of female midges. The female‐produced attractant did not alter field catches of maleC. im

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1994.tb01049.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract.Although the presence of small amounts of 3‐ethyl‐2,5‐dimethylpyrazine (EDMP) has been reported in the poison gland of thePheidole pallidulaminor workers, this substance is not the true trail pheromone of this ant. This pyrazine acts as an attractant and a locostimulant. Appropriate solvent extractions and thin‐layer chromatography of poison glands, together with trail bioassays, have shown that another substance acts as the trail pheromone. Furthermore, there seems to be an auxiliary pheromone, acting as a synergist; this might

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1994.tb01050.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract.Investigations of various species of moths have suggested that the biosynthesis of sex pheromone in the abdominal pheromone glands of females may be at least partly regulated by neuroendocrine mechanisms. Few studies, however, have explored the mechanisms underlying the release of sex pheromone. In experiments on the sphinx mothManduca sexta(L.) (Lepidoptera: Sphingidae), we have monitored the time course of sex‐pheromone release in scotophase females with the aid of an electroantennogram bioassay based on the highly sensitive and selective sex‐pheromone receptor neurones of the male antenna. Pheromone release was evoked by orthodromic stimulation of the ventral nerve cord. Neurally stimulated release occurred with a subsecond latency and did not depend on bioactive factors in the haemolymph or on movement of the abdomen or the ovipositor. Severing the most medial pair of nerves posterior to the terminal abdominal ganglion (the terminal nerves) eliminated pheromone release, but not abdominal contractions. Release was also inhibited reversibly if the descending Ca2+‐dependent synaptic input to the terminal ganglion was blocked by exposure to elevated concentrations of Mg2+. These findings indicate that the release of sex pheromone from the pheromone gland in femaleM. sextais a true neuroeffector response and that the gland appears to be controlled by neurones that project to it from the terminal abdominal gan

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1994.tb01051.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract.The mate choice, courtship and oviposition behaviour of laboratory‐reared and field‐collectedAnastrepha fraterculus(Wied.) were compared. In laboratory cultures in Southampton the duration of male calling activity in small leks increased gradually from 1‐2h at 5 days old to up to 7 h at 10 days. This finding correlates with previous reports on the time at which male salivary glands, which are believed to produce sex pheromone, are fully developed. Wild flies which emerged from infested fruits in Brazil began to oviposit on the day they mated, whereas in laboratory flies oviposition began 1 day following the first mating. Both types of fly usually defended their position on a particular fruit throughout the day, and re‐mated with either virgin or mated males. There was no significant difference in mating duration. Females did not copulate before the mean age (±SE) of 16.8±0.9 days. For both types of flies mating initiation occurred in the first 2h of photophase, with virgin females choosing mainly mated males. The average number of matings in the laboratory was three for females and four for males, and the interval between matings in females was significantly increased after the second mating. It is suggested that the tendency of virgin females to mate with mated males will lead to increased fitness, as males are on average 48 days old at their second mating. The potential life span of around 200 days for both sexes would allow adults to bridge the gap between seasonally available fruits in warm‐temperate and sub‐tropical

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1994.tb01052.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract.Electroantennograms (EAGs) were recorded from adult male and asexual forms (winged and wingless virginoparae and gynoparae) of the black bean aphid,Aphis fabae, during stimulation with two sex pheromone components, (+)‐(4aS,7S,7aR)‐nepetalactone and (‐)‐(1R,4aS,7S,7aR)‐nepetalactol, as well as six plant volatiles, i.e. (E)‐2‐hexenal, (E)‐2‐hexenol‐1, (Z)‐3‐hexenol‐1, (Z)‐3‐hexenyl acetate, hexanal and allyl isothiocyanate. The male antennae are 1000‐10,000 times more sensitive to nepetalactol and nepetalactone than to the plant compound (E)‐2‐hexenal. Besides this marked difference of EAG peak responses in males, the EAG rise and decay are slower for the sex pheromone components. Males are also much more sensitive to the sex pheromone components than asexual females. This high sensitivity correlates with a predominance of antennal secondary rhinaria, the major sites of pheromone perception in the male. However, it is the primary rhinaria on the antennae of the wingless asexual females that are responsible for pheromone perception. Male antennae are as responsive as the asexual female antennae to the plant volatiles. The specialization of the

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1994.tb01053.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract.The behavioural response of adults of the pollen beetle,Meligethes aeneusF. (Coleoptera: Nitidulidae), to the odour of one of their host‐plants, oilseed rape (Brassica napusL.), was observed in the laboratory using a fourarmed airflow olfactometer, and under semi‐natural conditions using a markrelease–recapture technique. Oilseed rape leaf and flower odour was attractive to pollen beetles in the olfactometer and they dispersed upwind from the centre of a circular array (radius 20 m) of yellow water traps, baited with extracts of oilseed rape leaves or flowers. The dispersal of pollen beetles in the absence of oilseed rape odour was predominantly downwind and crosswind. The percentage recapture of pollen beetles was significantly greater in traps baited with rape flower extracts than leaf extracts. Pollen beetles can use odour‐mediated upwind anemotaxis to locate oilseed rape plants from distances of at least 20 m over open

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1994.tb01054.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract.When exploring a chemically unmarked area devoid of food sources, workers of the pest antMonomorium pharaonisL. (Formicidae, Myrmicinae) leave scent marks on the ground and after 30–60min a network of diverging exploratory trails begins to emerge.Exploratory activity is affected by the nutritional state of the colony and a period of food deprivation induces a dramatic increase in the number of workers leaving the nest. A mathematical model based on a logistic growth equation is proposed to describe the exploratory recruitment observed. When travelling along exploratory trails the proportion of ants displaying trail‐laying behaviour is higher for outbound than for nestbound workers. Outbound ants also show a greater propensity than nestbound ants to follow the scent marks of their nestmates. The chemical used to mark a novel area does not appear to be colony‐specific and thus does not have a territorial functionsensu stricto.The adaptive value of the collective exploratory behaviour observed in this study is discussed in relation to the common features of other pest ant species described in the liter

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1994.tb01055.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract.An electroantennogram (EAG) apparatus for testing the activity of pheromones of the olive beetle,Phloeotribus scarabaeoides, is described. This inexpensive device is suitable for whole antennal recording from scolytids. The modification of the amplifier and sample injection system, described previously, eliminate parasitic noise and improve the recording of the EAG signal.Results from previous studies revealed significant beetle attraction to a source releasing ethylene. Serial solutions of 2‐chloro‐ethyl phosphonic acid were tested, and 10% acetic acid served as a standard.A significant variation in amplitude of depolarization was found among the different concentrations of 2‐chloro‐ethyl phosphonic acid tested. Maximum depolarization was elicited at a concentration of 0.1% in both males and females. In general, no statistical differences in responses were found between males and females, but females showed a significantly lower threshold of r

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1994.tb01056.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract.Tsetse fliesGlossina morsitans morsitansWestwood andG. pallidipesAusten were marked and released within 12 h of emergence at Rekomitjie Research Station, Zambezi Valley, Zimbabwe, and on Redcliff Island, Lake Kariba. Ovarian dissections were performed on recaptured flies and on wild collected samples. At Rekomitjie>90% of femaleG. m. morsitanswere inseminated by age 4 days andG. pallidipesby 7 days. For both species at both sites the length of the largest oocyte, for flies in ovarian category zero, increased approximately linearly for about the first 6 days and was ovulated atc.6–8 days. The largest oocyte grew significantly more slowly in later cycles. ForG. m. morsitans, but not forG. pallidipes, the rate increased with temperature; the rates were always higher than observed in the laboratory. At Rekomitjie, for both species and at a mean screen temperature of 22d̀C, the first larva was produced atc.18 days and subsequent larvae at 11–day intervals; the intervals decreased with temperature by c. 0.5 days/d̀C. On Redcliff Island the intervals for both species were 2 days shorter than at Rekomitjie at any given screen temperature and were sometimes as short as 7 days. The length of the larvain uteroincreased exponentially during preg

ISSN:0307-6962    

DOI:10.1111/j.1365-3032.1994.tb01057.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY