CULEX ANNULIROSTRIS SKUSE (DIPTERA: CULICIDAE) AT APPIN, N. S. W.—BIONOMICS AND BEHAVIOUR

Abstract
Larval and adult populations of Culex annulirostris were sampled for two years. Populations appeared in pond samples and dry-ice baited light traps in Oct, increased into mid summer, then disappeared in May. Larval populations appeared to reflect rainfall which promoted oviposition. The species overwintered as a female population that was predominantly parous. Females were more attracted to chickens than to guinea pigs. There was no evidence of autogeny in the population. The duration of the gonotrophic cycle ranged from 4 to 12 days depending on temperature. Females old enough to transmit arboviruses were present from Oct to May.     

STRUCTURE OF THE EGG-SHELL OF CULEX PIPIENS AND MANSONIA AFRICANA (CULICIDAE, DIPTERA)

Eggs of Culex pipiens L. are laid in rafts on the surface of still or slow moving water, whereas those of Mansonia africana (Theobold) are deposited beneath tho surface of the water on the undersides of floating leaves (Laurence & Smith 1958; Laurence 1959). The eggs of both species are surrounded by air, those of Culex pipiens are in direct contact with the external atmosphere, whereas those of Mansonia africana are partially surrounded by a bubble of air trapped between them. The anterior onds of the eggs of Mansonia africana project through the bubble of air into the surrounding water. This bubble of air is only found around living eggs and disappears if tho eggs die and shortly before they hatch. Iyengar (1935) has shown that the eggs of Ficalba minima Theo. although often deposited on the same leaf as those of Mansonioides , are laid above the water line and resemble in structure those of Culex and Coquillettidia . The structure of the egg-shell of both Culez pipiens and Mansonia africana is described and discussed.     

白纹伊蚊卵滞育的实验观察

对两个地理品系的白纹伊蚊卵期滞育的实验观察表明:白纹伊蚊宜兴品系(约北纬31°N)不仅亲代受短光照作用后可诱导卵期发生滞育,而且卵期仍具有光照敏感性;海南岛品系(约北纬18°N)中,光期变化不能诱导卵期滞育.宜兴品系卵滞育率随亲代光期缩短而增高的现象只发生在一定范围内(约L:D=9:15到L:D=15:9).卵滞育还受卵期低温、干燥以及孵化时水中溶解氧的影响.卵进入深度滞育是多种环境因素作用的结果.