Habrobracon hebetor ectoparasitism paralyzing effect on Corcyra cephalonica of different instar larvae

Corcyra cephalonica (Lepidoptera) is an important storage product pest that damages rice, corn and other grains. Habrobracon hebetor is a parasitic wasp that is capable of paralyzing lepidopteran pests. However, how C. cephalonica affects the prey preferences, fitness, and functional response of H. hebetor remains poorly understood. We therefore used selective and nonselective, age–stage two-sex life tables and functional response models to determine how this problem could be solved. Our results showed that H. hebetor preferred the 4th to last instar larvae of C. cephalonica and that its functional responses were consistent with the Holling II model in these three instars. However, the search ability of the 4th instar larvae was strong and its processing time was short. Additionally, generative development can be completed in the 4th to last instar larvae stage of C. cephalonica, whereas the 5th instar provided wasp predators with the best life history, population and paralysis rate parameters measured in this study. We also found that the wasp displayed its highest population size and total paralysis rate within 60 days on 5th instar prey. Thus, we conclude that 5th instar larvae are a suitable host for H. hebetor. These results not only provide a theoretical reason to use H. hebetor to control C. cephalonica infestation but also broadens the known host larvae selection range for industrial production of this parasitic wasp.

Methods
Age-stage tow-sex lifetable; SAS; SPSS

米蛾（Corcyra cephalonica，鳞翅目Lepidoptera）是一类重要的仓储害虫，可危害水稻、玉米等多种谷物。麦蛾茧蜂（Habrobracon hebetor）是一种能够麻痹鳞翅目害虫的寄生蜂。然而，目前关于米蛾如何影响麦蛾茧蜂的猎物偏好、适合度以及功能反应的研究仍较为匮乏。为此，本研究采用选择性与非选择性试验、年龄-阶段两性生命表（age–stage two-sex life tables）以及功能反应模型，对该问题展开探究。研究结果显示，麦蛾茧蜂偏好寄生米蛾的4龄至末龄幼虫，且在这三个龄期内，其功能反应均符合霍林II型（Holling II）模型。其中，麦蛾茧蜂对4龄幼虫的搜寻能力最强，且处理时长最短。此外，麦蛾茧蜂可在米蛾4龄至末龄幼虫阶段完成世代发育，但米蛾5龄幼虫为该寄生蜂提供了本研究中最优的生活史、种群参数以及麻痹率表现。同时，当寄主为5龄幼虫时，麦蛾茧蜂的种群规模与总麻痹率在60天内达到峰值。综上，本研究认为5龄幼虫是麦蛾茧蜂的适宜寄主。本研究结果不仅为利用麦蛾茧蜂防控米蛾虫害提供了理论依据，同时也拓宽了该寄生蜂工业化生产中已知的寄主幼虫选择范围。方法
年龄-阶段两性生命表；SAS；SPSS