内寄生蜂对寄主小菜蛾发育的调控能力研究

研究了菜蛾盘绒茧蜂Cotesia plutellae和半闭弯尾姬蜂Diadegma semiclausum 2种幼虫内寄生蜂对寄主小菜蛾Plutella xylostella生长发育的影响及2种蜂种间竞争能力。结果表明，菜蛾盘绒茧蜂寄生后，因多分DNA病毒（Polydnavims，PDV）和毒液的作用，能完全抑制寄主化蛹；半闭弯尾姬蜂寄生后，虽也有PDV和毒液的存在，但寄主小菜蛾仍可正常吐丝发育成预蛹。菜蛾盘绒茧蜂对寄主小菜蛾生长发育的抑制程度显著高于半闭弯尾姬蜂，寄生因子在调控寄主发育中发挥重要作用。2种蜂的种间竞争结果表明，多数情况下，菜蛾盘绒茧蜂是成功者，这说明寄生蜂所拥有的寄生因子是决定其寄生能力大小的生理基础。

The Capacity of Regulation on Development of Host Diamondback Moth, Plutella xylostella, by Endoparasitoids

Study was conducted on the effect of two endoparasitoids, Cotesia plutellae (Kurdjumov) (Hymenopera: Braconidae) and Diadegma semiclausum Hellen (Hymenoptera: Ichneumonidae) on the growth and development of the same host larvae, Plutella xylostella (Lepidoptera: Plutellidae) and the competitiveness between them.The result show that the PDV and venom of C. plutellae could prolong the period of host larvae development and inhibit host pupation. The PDV and venom of D. semiclausum also could inhibit host complete pupation, but the host still could develop into prepupal period. C. plutellae had stronger affect on host development than D. semiclausum. The competition experiments revealed that C. plutellae was a better competitor in most cases than D. semiclausum when both species parasitized the same host larvae. This shows that the parasitism factors of the endoparasitoids were the physiological bases for interspecific competitive interactions between two endoparasitoids C. plutellae and D. semiclausum.