瓜实蝇密度和蜂密度对印啮小蜂寄生效能的影响

Effects of Bactrocera cucurbitae and parasite density on the parasitism efficiency of Aceratoneuromyia indica

在实验室内以瓜实蝇幼虫作寄主研究了寄主密度和蜂密度对印啮小蜂寄生效能的影响。结果表明：印啮小蜂对瓜实蝇的寄生量受寄主密度影响显著。寄主密度为5-20头/管时,寄主密度的增加对印啮小蜂的寄生效能有增强作用,而当寄主密度过高时,寄主密度的增加会使印啮小蜂的寄生效能降低。印啮小蜂个体之间存在相互干扰作用。平均每头雌蜂的寄生量和寄生率、每头雌蜂产仔蜂量随蜂密度的增加而减少,说明蜂密度的增加降低了印啮小蜂的寄生效能。当蜂密度从2头/管增加到15头/管时,平均每头雌蜂寄生的瓜实蝇数量降低了近3/4。蜂虫比例越低,子代的雌性比率越高。

The effects of host and parasitoid densities on the parasitism efficiency of Aceratoneuromyia indica（Silvestri）to Bactrocera cucurbitae（Coquillett）were tested in the laboratory.The results showed that the parasitism of wasps was significantly affected by host density.When B.cucurbitae density was 5-20 individuals per tube,increasing host density had a beneficial effect on parasitism efficiency of A.indica,while too high host density had an unfavorable effect on parasitism efficiency.There was an intraspecific interference in A.indica.Parasitization,parasitism rate and progenies per female decreased as the parasitoid density increased.Parasitism efficiency of A.indica decreased with the increase in parasitoid density.When the parasitoid density increased from2 individuals per tube to 15 individuals per tube,almost 3/4-fold decrease in parasitism per female was recorded.The lower the ratio of wasp and host,the higher the female proportion.