棉铃虫齿唇姬蜂对入侵害虫草地贪夜蛾的寄生效能

Parasitism potency of Campoletis chlorideae on the invasive pest Spodoptera frugiperda

为探明棉铃虫齿唇姬蜂Campoletis chlorideae Uchida对草地贪夜蛾Spodoptera frugiperda(Smith)幼虫的控害潜能,本文首次研究了该蜂对草地贪夜蛾1~4龄幼虫的寄生能力和选择性,进一步比较其对棉铃虫Helicoverpa armigera(Hübner)和草地贪夜蛾幼虫的寄主选择性,以及子代繁育质量;并模拟田间进行室外笼罩寄生试验。结果表明,棉铃虫齿唇姬蜂能成功寄生1~3龄草地贪夜蛾幼虫,偏好2~3龄幼虫;当棉铃虫和草地贪夜蛾共存时,与对最适寄主棉铃虫87.1%的寄生率和选择系数0.57相比,该蜂对草地贪夜蛾的寄生率和选择系数较低,分别为65.7%和0.43,但总产卵量没有显著性差异。从被寄生草地贪夜蛾中所育子代的蜂体大小、卵巢管数量均低于从棉铃虫中育出的。室外笼罩寄生试验表明,该蜂对在玉米叶上取食的草地贪夜蛾的寄生率高达72.5%,后代发育正常,并能成功寄生草地贪夜蛾和棉铃虫幼虫。

To make clear of the parasitism potency,the parasitic ability and preference indexes of Campoletis chlorideae to different larval instars of Spodoptera frugiperda were firstly explored in the present study.Furthermore,the preference of C.chlorideae to two host insects between Helicoverpa armigera and S.frugiperda and the quality of the offsprings from these two parasitzed hosts were compared,and outdoor cage experiment outdoor were conducted.The results showed that C.chlorideae could parasitize the 1st,2nd and 3rd instars of S.frugiperda larvae,and preferred to the 2nd and 3rd larval instars.Compared with the optimum host H.armigera,the parasitism rate and preference index of this ichneumonid to S.frugiperda was respectively 65.7%and 0.43,lower than 87.1%and 0.57,respectively.However,the total fecundity had no significant difference.The body size and the number of ovarioles of the offsprings from parasitized S.frugiperda were lower than those from H.armigera.The outdoor cage experiment showed that the parasitism rate of this wasp to S.frugiperda feeding on maize leaves was up to 72.5%,and the offsprings could complete development normally and parasitize successfully the larvae of S.frugiperda and cotton bollworm.