螟黄赤眼蜂对草地贪夜蛾卵寄生效果评价

Evaluation of parasitism on eggs of Spodoptera frugiperda (J.E.Smith) by Trichogramma chilonis

为了明确螟黄赤眼蜂Trichogramma chilonis对草地贪夜蛾Spodoptera frugiperda(J.E.Smith)卵寄生效果,室内组建了螟黄赤眼蜂在草地贪夜蛾卵上的实验种群生命表,调查统计了释放螟黄赤眼蜂后田间草地贪夜蛾卵的寄生率和幼虫的虫口减退率,并分析了释放距离对寄生效果的关系。结果显示,螟黄赤眼蜂在草地贪夜蛾卵上的净生殖力R_(0)=10.8407,内禀增长率r_(m)=0.0.2220,周限生长率λ=1.2486,单雌平均产雌率R_(0)′=13.8877。放蜂区草地贪夜蛾卵块寄生率64.44%,卵粒寄生率35.42%,显著高于对照区,释放赤眼蜂第7天田间草地贪夜蛾虫口减退率58.92%,防效50.50%。释放距离为5 m内螟黄赤眼蜂对草地贪夜蛾卵寄生效果的无显著影响。结果表明螟黄赤眼蜂对草地贪夜蛾卵有较高的寄生效能,田间释放螟黄赤眼蜂对草地贪夜蛾卵具较高的寄生率和明显的幼虫虫口减退率,释放螟黄赤眼蜂对降低草地贪夜蛾虫源基数起着重要的作用。

For clarifying parasitism on Spodoptera frugiperda by releasing Trichogramma chilonis,life table of the experimental population of T.chilonis on S.frugiperda eggs was constructed in laboratory,and control efficacy of releasing T.chilonis for S.frugiperda was evaluated,and as well as the relationship between release distance and parasitic effect were analyzed.Results showed that net reproductive rate(R_(0)) and average female laying rate per female T.chiloni(R_(0)′) on S.frugiperda eggs were 10.8407 and 13.8877.Parasitism rate and decrease rate of S.frugiperda were 35.42%,58.92% by releasing T.chilonis.Control effect was not significantly affected by release distance within 5 m.Results indicated that releasing of T.chilonis had good control effect on S.frugiperda by high parasitic efficiency and the decreased population rate of larvae.Release of T.chilonis had played an important role in reducing the initial population size of S.frugiperda.