3种赤眼蜂对甜菜夜蛾和小菜蛾卵的寄生功能反应

为评估稻螟赤眼蜂Trichogramma japonicum Ashmead、螟黄赤眼蜂Trichogramma chilonis Ishii和玉米螟赤眼蜂Trichogramma ostriniae Pang et Chen对甜菜夜蛾Spodoptera exigua Hübner卵和小菜蛾Plutella xylostella Linnaeus卵的寄生潜能，本研究在室内条件下测试了3种赤眼蜂对不同密度甜菜夜蛾卵和小菜蛾卵的寄生率、寄生功能反应和搜寻效应。结果表明，稻螟赤眼蜂、螟黄赤眼蜂和玉米螟赤眼蜂对甜菜夜蛾卵和小菜蛾卵均有一定的寄生效应。螟黄赤眼蜂对甜菜夜蛾卵的寄生率、瞬间攻击率、寄生效能和搜寻效应均高于稻螟赤眼蜂和玉米螟赤眼蜂；3种赤眼蜂对小菜蛾卵的寄生率、瞬间攻击率、寄生效能和搜寻效应则表现为：稻螟赤眼蜂>螟黄赤眼蜂>玉米螟赤眼蜂。3种赤眼蜂对两种寄主的寄生功能反应均符合HollingⅡ型模型方程，表现为寄生量均随寄主卵密度的增加而升高，达到一定水平后趋于平稳。赤眼蜂的搜寻效应随寄主卵密度的增加而降低。综合分析可知，螟黄赤眼蜂对于甜菜夜蛾的控害能力优于稻螟赤眼蜂螟和玉米螟赤眼蜂，而稻螟赤眼蜂比螟黄赤眼蜂和玉米螟赤眼蜂更适合用于防控小菜蛾。

Functional response of three Trichogramma(Hymenoptera: Trichogrammatidae) to parasitizing Spodoptera exigua and Plutella xylostella eggs

To evaluate the parasitism capacity of Trichogramma japonicum Ashmead, Trichogramma chilonis Ishii and Trichogramma ostriniae Pang et Chen on eggs of Spodoptera exigua Hübner and Plutella xylostella Linnaeus. The parasitism rate, functional response and searching efficiency of three Trichogramma parasitizing S. exigua eggs were tested under five different host densities. It was found that T. japonicum, T. chilonis and T. ostriniae could parasitize the eggs of S. exigua and P. xylostella. The parasitism rate, attack rates, parasitism efficiency and searching efficiency of T. chilonis on S. exigua were higher than that of T. japonicum and T. ostriniae. The parasitism rate, attack rates, parasitism efficiency and searching effect of three Trichogramma on P. xylostella eggs were as follows: T. japonicum>T. chilonis>T. ostriniae. The type of functional response of the three Trichogrammas to the two hosts eggs were all type II, which showed that the number of eggs parasitized increased with the increase of host eggs density, and tended to be stable after reaching a certain level. While, the searching efficiency decreased with the increase of host eggs density. In conclusion, the control efficacy of T. chilonis against S. exigua is better than that of T. japonicum and T. ostriniae, and T. japonicum is more suitable for controlling P. xylostella.