虫螨腈对桑园害虫优势寄生蜂子代适合度的影响

Effect of Chlorfenapyr on the Fitness of Offspring of Dominant Parasitoid Wasps in Mulberry Field

虫螨腈是天然抗生素经改造合成的新型芳基吡咯类化合物,近年来在桑园推广用于防治桑尺蠖、斜纹夜蛾等桑树害虫。寄生蜂作为重要的生物防治手段,在桑园治虫中的潜力正愈发受到重视。子代适合度直接关系到寄生蜂控害潜能的正常发挥,所以,合理利用寄生蜂开展桑树害虫生物防治,必须探究常用化学药剂对寄生蜂子代适合度的影响。以虫螨腈及桑园害虫优势寄生蜂斑痣悬茧蜂为研究对象,室内测定农药暴露下寄生蜂的寄生效率及子代适合度指标。结果表明,虫螨腈处理斑痣悬茧蜂后,寄生率显著下降。子代蜂的发育历期不受虫螨腈处理和寄生时寄主体重影响,但这两个因素对茧历期影响显著。虫螨腈处理显著降低子代蜂的茧重和后足胫节长度,但寄生时寄主体重只影响子代蜂的后足胫节长度。此外,虫螨腈处理显著缩短了子代蜂的存活时间。研究表明,虫螨腈能显著降低斑痣悬茧蜂子代蜂的适合度指标,从而限制其生防效能的充分发挥,因此,在利用斑痣悬茧蜂开展桑树害虫生物防治时,必须严格注意两种防治手段的使用时期。

Chlorfenapyr is a new type of aryl pyrrole compound synthesized by the transformation of natural antibiotics.In recent years,it has been widely used in mulberry field to control Phthonandria atrilineata Butler,Spodoptera litura Fabricius and other insect pests.As an important biological control method,parasitoid wasps have been paid more attention to their potential in pest control in mulberry field.Therefore,to rationally use parasitoid wasps to carry out biological control of mulberry pests,it is necessary to explore the influence of commonly used chemicals on the offspring fitness of parasitoid wasps.In this study,Meteorus pulchricornis,which is the dominant parasitoid wasp in mulberry field,and chlorfenapyr are used as the research subjects.The parasitoid efficiency and offspring fitness of the parasitoid wasp under insecticide exposure were measured indoor.The results showed that the parasitoid rate decreased significantly after the treatment of chlorfenapyr.The developmental duration of offspring was not affected by the treatment of chlorfenapyr and the weight of the host body during parasitism,but the cocoon duration was significantly affected by these two factors.Chlorfenapyr treatment significantly reduced the cocoon weight and hind tibia length of the offspring,but the host weight only affected the hind tibia length of offspring.In addition,the treatment with chlorfenapyr significantly shortened the survival time of the offspring.This study shows that chlorfenapyr can significantly reduce the fitness index of the offspring of M.pulchricornis,thereby limiting the full play of its biological control efficiency.Therefore,if the population of M.pulchricornis were to be used to carry out biological control of mulberry pests,it should be necessary to strictly pay attention to the period of use of the two prevention methods.