迁飞对草地螟生殖行为及种群暴发的影响

为明确野外种群迁飞对草地螟生殖行为的影响及其在种群大暴发中的作用,对草地螟野外迁飞和未迁飞种群的生殖特征,包括首次产卵历期(period of first oviposition,PFO)及其他生殖参数进行了系统分析。结果表明,经历迁飞的种群与未经历迁飞的种群相比,成虫产卵前期、产卵历期、PFO和寿命均显著缩短;交配次数及交配率均显著增加;但平均每雌产卵量和卵孵化率无显著变化。这说明,尽管经历迁飞的草地螟种群产卵量未显著增加,但成虫到达迁入地后将很快多次交配、产卵,且产卵前期显著提前、产卵同步性显著增加,从而加剧后代种群暴发。

Effects of migration on reproduction and population outbreak in the beet webworm, Loxostege sticticalis

In order to further identify the reproductive consequences of insect migration and understand its ecological and evolutionary significance, reproductive traits including period of first oviposition (PFO) and other reproductive parameters of migrant and non-migrant populations were studied systematically. The results showed that preoviposition period, oviposition period, PFO and adult longevity of migrant population were significantly reduced as compared with those of non-migrant population. However, mating frequency and mating percentage were significantly increased, while adult lifetime fecundity and egg hatch rate did not vary significantly. The results indicated that, although adult egg production did not significantly increase, the migrant population could mate for several times quickly and oviposited in advance obviously, and the egg-laying synchrony increased significantly as well, which serve to increase the subsequent larval density and population outbreak.