Akinkurolere R O, Boyer Sebastien, Chen Haoliang, Zhang Hongyu
Hubei Key Laboratory of Insect Resource Application and Sustainable Pest Control and Institute of Urban Pests, College of Plant Science and Technology, Huazhong Agricultural University, People's Republic of China.
J Econ Entomol. 2009 Apr;102(2):610-5. doi: 10.1603/029.102.0219.
Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae) is a cosmopolitan insect infesting a broad range of commodities, including raw or processed cereal. It has a high fecundity and short generation time, making it a useful tool in testing host-parasitoid hypotheses. The current study examined the interactions between trophic levels during parasitism and host location by Habrobracon hebetor Say (Hymenoptera: Braconidae) within a closed environment by carrying out multiple tests to evaluate the role of refuge and host instar, on the mortality of P. interpunctella and on the emergence of H. hebetor. Results showed that H. hebetor was able to parasitize all instars (first through fourth) of P. interpunctella, but significantly fewer early instars (first through fourth) were parasitized. Parasitized third and fourth instars were more profitable to H. hebetor, irrespective of refuge or choice factors, as significantly more adult parasitoids emerged from third and fourth instars. H. hebetor females consistently showed a preference for fourth instars of P. interpunctella when they were offered a choice between early and late host instars in arenas both with and without a refuge. Generally, parasitization of early instars was higher in no-choice than in choice tests. The behavior of H. hebetor in relation to host choice and its influence on the pest mortality are discussed.
印度谷螟（Plodia interpunctella (Hübner)，鳞翅目：螟蛾科）是一种世界性昆虫，会侵害包括未加工或已加工谷物在内的多种商品。它繁殖力高且世代周期短，是检验寄主 - 寄生蜂假说的有用工具。本研究通过在封闭环境中进行多项试验，考察了哈氏大腿小蜂（Habrobracon hebetor Say，膜翅目：茧蜂科）在寄生和寻找寄主过程中营养级之间的相互作用，以评估庇护所和寄主龄期对印度谷螟死亡率及哈氏大腿小蜂羽化的影响。结果表明，哈氏大腿小蜂能够寄生印度谷螟的所有龄期（一龄至四龄），但被寄生的低龄期（一龄至二龄）个体显著较少。无论有无庇护所或选择因素，被寄生的三龄和四龄印度谷螟对哈氏大腿小蜂更有利，因为从三龄和四龄个体羽化出的成年寄生蜂显著更多。当在有和没有庇护所的试验场中，在低龄和高龄寄主龄期之间进行选择时，哈氏大腿小蜂雌蜂始终表现出对印度谷螟四龄幼虫的偏好。一般来说，在无选择试验中，低龄期的寄生率高于有选择试验。本文讨论了哈氏大腿小蜂在寄主选择方面的行为及其对害虫死亡率的影响。
