Epigamic display and unique mating position inWyeomyia arthrostigma (Diptera: Culicidae)

The mating behavior ofWyeomyia arthrostigma is more complex than that reported forW. smithii. Like some other genera in the tribe Sabethini, flyingW. arthrostigma males approach females perching on vertical sticks. A male aligns himself next to a female by seizing her wing and flipping sideways to land next to her, rather than beneath her. He then performs a series of abdominal bobbing movements, the pair achieves superficial genital coupling while the male's proboscis rotates and snaps down, and the antennae spread farther apart. Finally, the pair shifts to full copulation, and in this phase insemination occurs. In the copulatory position the abdomens of male and female are almost at right angles to each other, made possible by a twisting of the male's terminal segments. The nature of the mating process and its similarity to some elements ofSabethes andTopomyia mating indicate that males may be performing a courtship display.     

Courtship behavior of the mosquitoSabethes cyaneus (Diptera: Culicidae)

Unlike any other mosquito reported, Sabethes cyaneus(Fabricius) displays an elaborate courtship before and during copulation. A male approaches a female suspended from a horizontal stick, suspends himself in front of her as he grasps her folded wings, and proceeds with a series of discrete stereotyped behaviors that involve proboscis vibration and movement of iridescent blue paddles on his midlegs. The sequence of these behaviors is as follows: freeleg waving, swinging, copulation attempt, superficial coupling, waving, genital shift, waggling, and release. Insemination occurs after genital shift. The only overt reciprocation by the female is abdomen lowering during the male's swinging. Courtship is often unsuccessful, and males are usually rejected during freeleg waving. The relation between male performance and mating success remains obscure.     

Ploidy levels and DNA synthesis in fat body cells of the adult mosquito,Aedes aegypti: The role of juvenile hormone

Adult females of the mosquito Aedes aegypti showed two cycles of DNA replication in the fat body based on microspectrophotometric measurement of changes in nuclear DNA. The first cycle began after emergence and resulted in 80% of diploid fat body cells becoming tetraploid and 20% becoming octoploid by the end of the third day. The second replication cycle occurred 48–72 h after a blood meal and resulted in an increase in octoploid nuclei to 67% Topical application of juvenile hormone or methoprene to abdomens isolated at emergence stimulated an increase in ploidy levels above that normally seen in situ. Synthesis of DNA, estimated by incorporation of injected [³H]-thymidine, rose after emergence and remained high for 2 days. Synthesis increased again after a blood meal, reached a peak by 6 h, and returned to low levels by 24 h after the meal. The timing of DNA synthesis and a measurable increase in ploidy were temporally separated. The ploidy increase, but not DNA synthesis, was correlated with increases in juvenile hormone levels.     

Courtship and mating by the sandfly Phlebotomus duboscqi, a vector of zoonotic cutaneous leishmaniasis in the Afrotropical region

Courtship behaviour of males of the Afrotropical sandfly Phlebotomus duboscqi Neveu-Lemaire (Diptera: Psychodidae) involved mounting the female and clasping her 'waist' with the male coxites placed between the female's thorax and abdomen. This behaviour, which we call 'piggy-backing', was preceded by male wing beating, perhaps involving mate recognition and contact pheromones. It did not seem to be pre- or postcopulatory mate guarding. Piggy-backing was attempted by P. duboscqi males on females of other species (P. papatasi and P. perniciosus) and even on other male P. duboscqi. The majority of female P. duboscqi piggy-backed by males were already inseminated, and most of the courting did not lead to copulation. This, coupled with the presence of a mating plug (semen) in each spermatheca of inseminated females, suggests that female P. duboscqi are monogamous for at least the first gonotrophic cycle. Male courtship with piggy-backing was more intense when females could feed on a hamster than when a hamster was present but the females were denied access to the host. It is suggested that, when a hamster was available to the females, the conditions in the laboratory are similar to those in rodent holes, the natural habitat of P. duboscqi.     

Seasonality, biting cycle and parity of the yellow fever vector mosquito Haemagogus janthinomys in Trinidad

1. Age composition, seasonal abundance and diel patterns of landing activity of the sylvan vector of yellow fever Haemagogus janthinomys Dyar were monitored weekly during 1981-82 by human collectors on the ground at Point Gourde in Chaguaramas Forest, 16 km west of Port of Spain, Trinidad. 2. Landing collections of Hg. janthinomys showed only diurnal activity, from 06.00 to 18.00 (sunrise to sunset, universal time), with a single peak of activity between 10.00 and 16.00 hours. 3. Densities of Hg. janthinomys were about 6 times greater during the wet season (May-November) than during the dry season (December-April); the annual Williams' mean landing rate on two collectors was 9.3 per day. 4. Monthly parous rates averaged 59% (range 0-86%) and some females were up to seven-pars. Retained eggs (range 1-21, mean 7.7/female) were found in the ovaries of 1.3% of landing females, all of which had stage I ovarian follicles for the next gonotrophic cycle. Hence blood-feeding is not inhibited by egg retention, which might promote transovarial transmission of virus. Implications of these findings are discussed in relation to yellow fever epidemiology.     

Seasonal abundance, biting cycle and parity of the mosquito Haemagogus leucocelaenus in Trinidad, West Indies

Adult female populations of Haemagogus leucocelaenus (Dyar and Shannon), the sylvan vector of yellow fever, were monitored weekly during 1981–82 by human collectors on the ground at Point Gourde in Chaguaramas Forest, 16 km west of Port of Spain, Trinidad.
Hg.leucocelaenus showed only diurnal landing activity, from 06.00 to 18.00 hours (sunrise to sunset, universal time), with a single peak of activity between 10.00 and 14.00 hours.
Densities of Hg.leucocelaenus during the wet season (May–November) were about double the level recorded during the dry season (December–April).
Monthly parous rates averaged 53.9% (range 25–90%) and some females were up to five-pars. Retained eggs (range 2–6, mean 4/female) were found in the ovaries of 0.34% of landing females, all of which had stage 1 ovarian follicles for the next gonotrophic cycle. Therefore blood-feeding is not inhibited by egg retention. Hg. leucocelaenus vector potential is reappraised in the light of these findings.     

Seasonal abundance,biting cycle,parity and vector potential of the mosquito Haemagogus equines in Trinidad

Abstract. The mosquito Haemagogus equinus is a known vector of yellow fever (YF) in central America. Seasonal abundance, daily biting activity and the age composition of adult Hg. equinus female populations were monitored weekly during 1981–82 by human collectors on the ground at Point Gourde Forest, Chaguaramas, 16 km west of Port of Spain, Trinidad. 2. Landing collections of Hg.equinus showed diurnal activity from 06.00 to 20.00 hours (suntime), with a single peak between 08.00 and 14.00 hours. 3. Overall, 5.6% of Hg.equinus were collected during the dry season (December-April) and 94.4% during the wet season (May-November). 4. Mean density of Hg.equinus in relation to man ranged from 0.35/man-day in February to 133/man-day in July, with averages of 2.8 in the wet season, 36.9 in the dry season and 22/man-day for the whole year. 5. Monthly parous rates averaged 62.1% (range 0-88%); 2.8% of females were 2-pars, another 2.8% were 3-pars, but no older females of Hg.equinus were found (sample size 467). 6. These age-grading data indicate that Hg.equinus females have relatively short life expectancy and hence low vector potential, which may help to explain why YF virus has seldom been isolated from this vector species.     

Organosulphur constituents in garlic oil elicit antennal and behavioural responses from the yellow fever mosquito

Garlic (Allium sativum) and its essential oil have long been used for their distinct flavour, therapeutic effects and as a topical and systemic insect repellent. We tested the hypothesis that the yellow fever mosquito, Aedes aegypti L. (Diptera: Culicidae), responds electrophysiologically and behaviourally to specific components of the steam‐distilled essential oil of garlic. In coupled gas chromatographic‐electroantennographic detection analyses of garlic oil, antennae of female Ae. aegypti responded to 14 compounds. Seven of them [diallyl disulphide, diallyl trisulphide, diallyl tetrasulphide, 2‐(2,3‐dithia‐5‐hexenyl)‐3,4‐dihydro‐2H‐thiopyran, 3‐(2,3‐dithia‐5‐hexenyl)‐3,4‐dihydro‐2H‐thiopyran, 6‐methyl‐4,5,8,9‐tetrathiadodeca‐1,11‐diene and 4,5,9,10‐tetrathiatrideca‐1,12‐diene] were isolated or synthesized and tested for their ability to repel host‐seeking female Ae. aegypti. A solution of diallyl trisulphide and diallyl tetrasulphide applied to a human forearm provided protection from female mosquitoes significantly longer than the paraffin oil control. All compounds had mean protection times significantly shorter than an equivalent dose of the ‘gold standard’N,N‐diethyl‐3‐methylbenzamide. Understanding the common moiety in organosulfur compounds that causes repellence could lead to the design of analogues that are more effective than their natural counterparts in repelling mosquitoes.     

果蝇求偶行为的影响因素及其分子基础

果蝇Drosophila melanogaster Meigen是进行行为遗传学研究的极好材料。果蝇的雄性求偶行为已经被作为行为遗传学研究的模式。文章简要介绍近年来在遗传和分子水平上对果蝇性信息素和求偶行为的研究进展,尤其是突变体在果蝇行为遗传学研究中的应用。通过对果蝇求偶行为的分析,分别介绍果蝇的性信息素及视觉、听觉、嗅觉和味觉相关基因在果蝇求偶和交配行为过程中的作用。     

Use of behavior to evaluate reproductive problems in captive mammals

Behavioral analyses constitute a logical starting point for discerning the causes of reproductive failure in captive mammals and should be completed before moving on to more invasive diagnostic procedures. Behavioral inadequacies affecting reproductive performance may be attributable to deficient early rearing environments, to the social milieux in which breeding-age animals are held on a long-term basis, or in the way pairings for mating are staged. Diagnoses may be focused on uncovering motivational, motoric, social, or communicative deficiencies. A biologically based approach which integrates species-typical behavior with concerns for genetics, physiology, and health in designing breeding programs will improve prospects for success. © 1994 Wiley-Liss, Inc.     

龙平莱蛛(蜘蛛目,泰莱蛛科)的求偶和交配行为

泰莱蛛科属于简单生殖器类蜘蛛,为洞穴蜘蛛的主要类群.本实验首次在实验室条件下对泰莱蛛科蜘蛛龙平莱蛛Pinelema bailongensis的求偶和交配行为进行描述:雄蛛可与多个雌蛛交配,雌蛛一般为单次交配.一次完整的交配进行2～8次交尾,交尾时间为0.27～5.03 min.求偶行为主要涉及探足、腹震和拍足等动作.     

Multiply Mating Males in Gnamptogenys striatula Mayr (Hymenoptera, Formicidae)

Multiply mating ant males are rare, because in most ant species, multiple mating opportunities for males are scarce. Gnamptogenys striatula is an exception to this rule, as intranidal mating offers protection and a local female-biased sex ratio. In a behavioral experiment, we confirm the males’ ability to inseminate several receptive workers, with four females being the observed maximum. D. Allard is a Research Assistant for the Fund of Scientific Research—Flanders.