白蛾黑基啮小蜂寄主接受行为因子的探讨

Probe of host acceptance factor of Tetrastichus nigricoxae Yang

白蛾黑基啮小蜂(Tetrastichus nigricoxae Yang)是徐州地区杨小舟蛾(Micromelalopha troglodyta)蛹期的1种重要天敌。研究证明,白蛾黑基啮小蜂主要是通过嗅觉来识别寄主蛹的,并且它能够辨别已寄生蛹和未寄生蛹,避免了因重复寄生而造成子代小蜂不能完成世代发育。未寄生的杨小舟蛾蛹表提取物中含有大量羊毛甾醇(62.411%),而寄生过的杨小舟蛾蛹表提取物中不存在该物质。高浓度的未寄生蛹表提取物能够引诱白蛾黑基啮小蜂,而已寄生蛹表提取物对小蜂无引诱作用。2种提取物均不能提高白蛾黑基啮小蜂对杨小舟蛾的寄生率。

Tetrastichus nigricoxae Yang parasitizes mainly on the Micromelalopha troglodyta Graeser pupae in Xuzhou City.Our research showed that olfaction of the female chalcid played the major role in its host acceptance. And T. nigricoxae Yang could also identify the non-parasitized and parasitized pupae to avoid hyperparasitization. The shell extractive of the non-parasitized pupae that could attract the chalcid contained a large number of lanosterol（ 62. 411%）,which did not exist in the shell extractive of the parasitized pupae. Both of the extractives could not attract the chalcid to gain more hosts.