中文摘要：

为探究容性寄生蜂对不同龄期寄主幼虫的选择性及其子代蜂发育表现的关联,通过双选试验观察了斑痣悬茧蜂（Meteorus pulchricornis）对斜纹夜蛾（Spodoptera litura）不同虫龄幼虫的寄生选择,并观察了与子代蜂适合度相关的特性表现。结果表明：斑痣悬茧蜂在4龄与5龄之间未表现出偏好,在2龄和3龄、3龄和4龄之间显著偏好较低虫龄;结茧率在不同寄主虫龄间无显著差异,羽化率随寄主虫龄增大而减小,寄生2、3龄幼虫的子代蜂显著高于寄生5龄;寄生5龄幼虫的子代蜂死亡率比寄生2龄的高2.5倍,比寄生3龄的高5.4倍。寄生3龄幼虫的子代蜂发育历期最短（11.9 d）,比寄生4龄幼虫的短6.8 d,比寄生2龄幼虫的短4.7 d;子代蜂体型大小在寄生的寄主虫龄间无显著差异。根据研究结果推测,斑痣悬茧蜂在寄生时可能不是根据寄主龄期来评价寄主品质,而是基于寄主体型大小进行评价。

英文摘要：

A dual-choice experiment was conducted to observe the host selection and offspring developmental performances of koinobiontic parasitoid Meteorus pulchricornis on Spodoptera litura larval instars（except the first and last instars）.The parasitoid showed no preference for L4 and L5,but exhibited preference to lower instar larvae in L2 vs.L3 and L3 vs.L4.No significant difference was observed in the cocoon formation rate among the offspring parasitoids from different host instars at oviposition.The emergence rate decreased with the increase of host instars,and was higher from attacking L2 and L3 than that from attacking L5.The mortality rate of the offspring developed from attacking L5 was 2.5 times higher than that from attacking L2,and 5.4 times higher than that from attacking L3.The offspring developed from attacking L3 had the shortest development time（11.9 days）,being 6.8 days shorter than that from attacking L4 and 4.7 days shorter than that from attacking L2.There were no significant differences in the body size of progeny parasitoids on host instars at oviposition,as measured by hind tibia length.This study suggested that M.pulchricornis based its host selection more on host body size or its related characters than on host development stage per se.