斜纹夜蛾侧沟茧蜂对寄主龄期的选择

Preference of Microplitis sp. to Host Age

应用均匀设计研究了斜纹夜蛾侧沟茧蜂与斜纹夜蛾 1龄末～ 2龄初幼虫、3龄幼虫和 4龄幼虫共存系统中 ,寄生蜂对不同龄期幼虫的选择寄生作用 ,建立了 3个龄期的幼虫被寄生量模型 .根据模型 ,计算了寄生蜂对 3个龄期幼虫寄生的选择系数 .结果表明 ,斜纹夜蛾侧沟茧蜂能寄生斜纹夜蛾 1～ 4龄幼虫 ,但当 1龄末～ 2龄初幼虫、3龄幼虫和 4龄幼虫同时存在时 ,该蜂偏爱寄生 1龄末～ 2龄初幼虫 ,其次为 3龄幼虫 .

Selective parasitism of Microplitis sp. to the end of 1st ~ the beginning of 2nd larvae,3rd instar larvae and 4th instar larvae of Spodotpera litura in co existence system of three host age was studied by the uniform design,and the parasitism models were established by progressive regressive analysis.Moreover,the preference index of Microplitis sp.to host age was calculated according to the parasitism models.The results show that Microplitis sp. parasitizes 1~4 instar of Spodotpera litura ,but it preferres to parasitize the end of 1st larvae ~3rd instar larvae when it is exposed to the end of 1st ~ the beginning of 2nd instar larvae,3rd instar larvae and 4th instar larvae of Spodotpera litura.