大灰食蚜蝇幼虫饲养及温室释放试验

在室内用桃蚜、蔷无网蚜、桃粉大尾蚜、菊花蚜虫4种蚜虫饲养大灰食蚜蝇幼虫取得比较满意的结果,幼虫成活率76～80％,蛹羽化率92～94％,子代卵孵化率84～91％。用豌豆修尾蚜饲养,幼虫成活率仅48％,蛹羽化率50％,子代卵孵化率无明显差异。在大灰食蚜蝇幼虫发育期中,前期用桃蚜饲养,后期改用修尾蚜饲养,对幼虫成活率及蛹羽化率仍有影响.食物(蚜虫)充足时,幼虫自残程度低,可以集体饲养。以1:10的益害比释放大灰食蚜蝇3日龄幼虫,防治非洲菊上的蚜虫,3天后蚜虫下降85.9％,效果显著。

EXPERIMENTS ON REARING AND GREENHOUSE RELEASE OF THE LARVAE OF METASYRPHUS COROLLAE [DIP.:SYRPHIDAE]

In laboratory experiments conducted in Beijing, larvae of Metasyrphus corollae were reared with four species of aphids: Myzus persicae, Rhodobium porosum, Hyaloptera amygdali and Aphis sp.. The rates of larval surviving, adult emergence, and F1 generation egg hatch were 76.8-80%, 92-94% and 84-91%, respectively. The larval surviving and adult emergence rates reduced to 48% and 50%, respectively, when the larvae were reared with a different aphid, Megoura japonica. Feeding the larvae alternatively with suitable and unsuitable prey, i.e. with M. persicae in the early larval stage while using M. japonica in the late stage, also affected the larval survival and adult emergence rates. Larval cannibolization was reduced when adequate prey (aphids) was provided, which made the mass rearing of this predator possible. Releasing the 3-day old larvae at a predator-prey ratio of 1:10 to control the aphid Uroleucon sp. on Flameray genbera resulted in a 85% reduction of the aphid population 3 days after the release.