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441.
ABSTRACT. Homogenates of accessory glands from male Culex tarsalis Coquillet (Diptera; Culicidae) were fractionated using gel filtration column chromatography. A component of low molecular weight capable of suppressing female sexual receptivity was obtained and partially characterized. Proteins present in homogenates of isolated accessory glands formed aggregates with other proteins in extracts of whole mosquitoes. Consequently, previous reports of the molecular weight of biologically active components in homogenates from accessory glands from other mosquito species may be inaccurate.
When female Cx. tarsalis were mated with3 H-leucine labelled males. radioactivity could be found throughout the body of the female 24 h after mating. Autoradiography showed that the radioactivity was incorporated into the cells of various organs, and was not specifically localized in a particular target tissue. Approximately 30% of the total radioactivity transferred to the female was found in the head and thoracic regions, and proteins from the head had a specific activity twice that of the thoracic proteins. Bioassay of isolated body parts from mated and virgin females showed that injections of head tissues from mated females into virgin females suppressed sexual receptivity. These results suggest that the head is involved in the physiological mechanisms resulting in refractory mating behaviour. 相似文献
When female Cx. tarsalis were mated with
442.
S. E. HEADY 《Physiological Entomology》1993,18(3):263-270
Abstract. The mating system of Prokelisia dolus Wilson (Homoptera: Delphacidae) was characterized by determining: if males and females multiply mate; when transitions occur in female sexual receptivity, what triggers sexual refractoriness; and what behaviours characterize unreceptive virgins, receptive virgins, and unreceptive mated females. Males copulated with up to six females in less than 1 h, but completely inseminate, on average, only the first four females. Females rarely mated more than once, unless males were depleted of sperm due to previous copulations or if copulation was interrupted (if duration was<2 min). Male and female calling was associated (100% and 91%, respectively) with sexual receptivity and resultant matings. The transition from unreceptive virgin to receptive (calling) mature virgin occurred 48 h posteclosion, and all were mated by day 4. Females that were sexually immature and those completely inseminated did not call. Rejection of males by females included walking away from approaching males (65%), female kicking (7%), and abdominal lifting (5%). Rejection of males was observed by immature, mature and calling, and mated females. Sexual refractoriness was not triggered by acoustic and visual stimuli or mechanical stimulation of genitalia. Refractoriness was also not triggered by reception of small quantities of sperm because some females laid a few viable eggs yet calling was not terminated. Sexual refractoriness was activated by a substance in the ejaculate as demonstrated by injection into the haemocoel of male accessory glands or testes and homogenates of seminal vesicles. This is the first study that documents the role of male ejaculate in inhibiting female sexual receptivity in Hemiptera (Homoptera). 相似文献
443.
444.
Raymond Beach 《Journal of insect physiology》1980,26(4):245-252
The effectors which erect antennal hairs in male mosquitoes are shown to be unresponsive to the neurotransmitter that triggers antennal hair erection until 12–24 hr after emergence.The unresponsive period can be prolonged by transfusion of haemolymph from newly-emerged males, or by injection of 20-hydroxyecdysone. This suggests that the hormone persisting after the metamorphosis from pupa to adult, affects the duration of the post-emergence delay in antennal hair erection and is indirectly responsible for timing the onset of sexual receptivity in male mosquitoes. 相似文献
445.
A study of the effective pollination period (E.P.P.) of six varieties of apricot has shown that in the warm climate of the South Mediterranean this parameter is extremely short. The percentage of fruit set of emasculated flowers diminishes rapidly with time. Temperature plays an important role in this process and is responsible for the rapid degradation of the stigma, which hinders pollen germination. 相似文献