江淮棉区棉大卷叶螟主要寄生性天敌的寄生作用

通过大田调查与室内饲养观察结果表明,江淮棉区棉大卷叶螟Sylepta derogataFabricius的主要寄生蜂(蝇)有7种:卷叶螟绒茧蜂Apanteles derogatae(Watanabe)、叶卷蚁形蜂Goniozus japonicus(Ashmead)、卷叶螟姬小蜂Sympiesissp.、菲岛扁股小蜂Elasmus philippinensis(Ashmead)、广黑点瘤姬蜂Xanthopimplapunctata(Fabricius)、广大腿小蜂Brachymeria lasus(Walker)和玉米螟厉寄蝇Lydella grisescens(Robineau-Desvoidy)。其中,卷叶螟绒茧蜂和卷叶螟姬小蜂为棉大卷叶螟幼虫期优势寄生蜂种,广大腿小蜂为幼虫-蛹跨期优势寄生性天敌。自然情况下,棉大卷叶螟的被寄生率高达25.7%,寄生性天敌对棉大卷叶螟种群起着重要的控制作用。

Identification and behaviors of parasitoids of Sylepta derogata in the Yangtze River and Huihe Valley

A survey of parasitoids of the cotton leaf-roller,Sylepta derogata Fabricius,in the cotton fields of the Yangtze River and Huihe River Valley was conducted by both field sampling and laboratory rearing.The following seven species of parasitoids were recorded: Apanteles derogatae(Watanabe),Goniozus japonicus(Ashmead),Sympiesis sp.,Elasmus philippinensis(Ashmead),Xanthopimpla punctata(Fabricius),Brachymeria lasus(Walker)and Lydella grisescens(Robineau-Desvoidy).Among them,A.derogatae and Sympiesis sp.were the dominant species of the larval stage.B.lasus was the dominant species of the larvae-pupae period.The rate of parasitism of cotton leaf-roller reached up to 25.7% in the field.These parasitoids seemed to play an important role in suppressing the population of the cotton leaf-roller.