不同龄期菜蚜茧蜂对蚜虫宽缘金小蜂发育的影响

田间收集蚜虫宽缘金小蜂Pachyneuron aphidis(Bouche)，采用室内饲养的方法，研究了不同龄期菜蚜茧蜂Diaeretella rapae M’Intosh对蚜虫宽缘金小蜂发育的影响，蚜虫宽缘金小蜂寄生菜蚜茧蜂的蛹，是体外寄生蜂，其对处于预蛹期前的菜蚜茧蜂不会有寄生行为．随着菜蚜茧蜂蛹龄的增加，蚜虫宽缘金小蜂的发育历期由15．22d逐渐缩短为12．21d，重寄生率也由15％逐渐降低为3％，蚜虫宽缘金小蜂的个体发育可分为卵、工龄幼虫、Ⅱ龄幼虫、Ⅲ龄幼虫、预蛹、蛹等6个阶段，文中对各发育阶段作了详细描述，并附有相应的图片。

Influence of different stages of Diaeretiella rapae on development of Pachyneuron aphidis

Five species of hyperparasitoids of Diaeretiella rapae M'Intosh on aphids in vegetables field in Guangzhou, China, were found, and they are: Pachyneuron aphidis (Bouche), Syrphophagus aphidivorus (Mayr), Alloxysta fuscicornis Hartig, Dendrocerus aphidum(Kieffer) and Dendrocerus sp.; P. aphidis is an important hyperparasitoid suppressing the natural population of D. rapae. However, the growth stages of D. rapae affected the development of P. aphidis. The results from experiment showed that the development duration of P. aphidis was 15.22 d in the stage of D. rapae in pre-pupa in 1-24 h significantly longer than in pre-pupa in 48-72 h (12.21 d), while the hyperparasitism of P. aphidis was 15% in pre-pupae of D. rapae in 1-24 h significantly higher than in pre-pupa in 48-72 h(3%). The development phases of P. aphidis including egg, 1~(st) instar larva, 2~(nd) instar larva, 3~(rd) instar larva, pre-pupa and pupa, were described and their photos were given.