光周期对荔蝽卵平腹小蜂日产卵量及后代性比的影响

EFFECT OF PHOTOPHASE DURATION ON DALLY OVIPOSITION AND THE PROGENY SEX RATIO OF ANASTATUS JAPONICUS [HYM.:EUPELMIDAE]

在室内用柞蚕剖腹卵为寄主在温度25±1℃、相对湿度70～85％、光照强度500lx条件下研究不同光周期(0L:24D、6L:18D、12L:12D、18L:6D和24L:0D)对荔蝽卵平腹小蜂日产卵量及后代性比的影响。结果表明,在5个不同光周期处理之间,平腹小蜂日产卵量没有显著差异,在无光照条件下也可以正常产卵,除24L:0D外其它4个处理,在一天中不同时间的产卵数有显著差异,而且在5L:18D、12L:12D和18L:6D3个处理中均以上午6:00～12:00期间的产卵数最多,分别占全天总产卵量的53.3％、50.8％和38.0％。5个光周期处理的平腹小蜂后代雌性比有显著的差异,在6L:18D光照条件下后代雌性比最高,其次是0L:24D、12L:12D和18L:6D,而24L:0D即全光照条件下雌性比最低。各个处理在一天中不同时间的后代雌性比均无显著的差异。

Experiments on the effect of photophase on daily oviposition and progeny sex ratio of Anastatus japonicus, an egg parasitoid of the lychee stink bug, were conducted in the laboratory of 25.1℃, 70-85% RH and 500 lux lighting in 1991. Five different light:dark regimes were used in the experiment viz. 0:24 (hr), 6:18, 12:12, 18:6 and 24:0. The result revealed no significant difference in the parasitoid's daily oviposition among the 5 photophase regimes, but in sex ratio of the progenies. The parasitoid could lay eggs normally even under continuous dark conditions, although most eggs were laid during 6:00-12:00 am in the treatment of 6L:18D, 12L:12D and 18L:6D. The highest female rate of the progeny was found when the parent wasps were cultured under 6 hr photophase and 18 hr darkness, followed by that under 0L:24D, 12L:12D and 18L:6D. Continuous lighting resulted in the lowest female rate. Progeny's sex ratio from the eggs laid during different times of a day was not significantly different.