5种赤眼蜂对草地贪夜蛾卵的寄生能力研究

The Parasitic Capability of Five Trichogramma Species on Eggs of Fall Armyworm Spodoptera frugiperda

草地贪夜蛾是一种原产于美洲地区的多食性和迁飞性害虫。自2019年初入侵我国以来已蔓延至21个省(市、自治区),对我国的玉米生产造成重大威胁。为探讨草地贪夜蛾的长效控制体系,我们考察了5种国内常见的赤眼蜂对草地贪夜蛾寄生能力的影响,同时选择寄生能力较好的2种赤眼蜂进行了驯化培养。结果显示在供试赤眼蜂中,松毛虫赤眼蜂对草地贪夜蛾卵的寄生能力最强,平均单雌可寄生20粒卵;碧岭赤眼蜂次之,平均单雌可寄生9.6粒卵;玉米螟赤眼蜂几乎不能寄生,平均单雌仅为1粒卵。对松毛虫赤眼蜂和碧岭赤眼蜂利用草地贪夜蛾卵驯化多代后发现松毛虫赤眼蜂的寄生能力无显著变化,而碧岭赤眼蜂经过4代驯化后有明显的提高,由平均单雌寄生9.6粒卵提高至13.4粒。综上所述,供试的5种赤眼蜂均可寄生草地贪夜蛾卵,其中以松毛虫赤眼蜂和碧岭赤眼蜂的寄生能力最强,通过多代驯化碧岭赤眼蜂对草地贪夜蛾卵的寄生能力具有提升的趋势,因此国内本土的赤眼蜂也具有防治草地贪夜蛾的潜力。

Fall Armyworm(FAW),Spodoptera frugiperda,is a polyphagous and migratory pest from the Americas.Since its invasion into China at the beginning of 2019,it has spread to 21 provinces(Autonomous Regions,Municipalities),which might pose a major threat to corn production in China.In order to explore the long-term control system of FAW,we examined the parasitic capacity of five native Trichogramma species on FAW eggs.Furthermore,two Trichogramma species,which performed best against FAW eggs,were reared on FAW eggs for four generations for a possible improvement in performance.The results show that among the tested Trichogramma species,T.dendrolimi had the strongest parasitic capacity on FAW eggs,with an average of 20 parasitized eggs per female wasp,followed by T.bilingensis,which could parasitize 9.6 FAW eggs per female wasp.T.ostriniae could rarely parasitize FAW eggs,with only 1 FAW egg per female wasp.After continuous rearing on FAW eggs for four generations,T.dendrolimi did not show a change in parasitic capacity while T.bilingensis showed an increase in fecundity from 9.6 eggs to 13.4 eggs per female.In summary,the five tested Trichogramma species all can parasitize FAW eggs,and the parasitic capacity of T.dendrolimi and T.bilingensis are better than the others.After multi-generational continuous rearing on FAW eggs,the parasitic capacity of T.bilingensis was improved.Thus,the native Trichogramma also has the potential to control FAW.