Behavioral responses of Dolichogenidea tasmanica to alternative hosts

The braconid, Dolichogenidea tasmanica (Cameron) (Hymenoptera: Braconidae), is the most abundant parasitoid attacking the light brown apple moth (LBAM) Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae), which represents the major insect pest of grapevines in Australia and New Zealand. Enhancing populations of alternative hosts for the parasitoid is one way to promote conservation biological control of this insect pest. The host foraging behavior of this parasitoid in response to E. postvittana and two related alternative hosts, Acropolitis rudisana (Walker) and Merophyas divulsana (Walker), was investigated in the laboratory to evaluate the viability of this approach. All hosts were accepted by the wasp with above 70% parasitism rate. During behavioral assays, the parasitoid responded differently to the host species, possibly due to differences in their physical characteristics, and their feeding and defensive behaviors. The results of the experiments indicate that populations of D. tasmanica should be enhanced by the presence of the alternative hosts, A. rudisana and M. divulsana. Conservation of D. tasmanica in agricultural landscapes is crucial for the conservation biological control of LBAM.

膜翅目（Hymenoptera）茧蜂科（Braconidae）的塔斯曼尼亚长茧蜂（Dolichogenidea tasmanica (Cameron)）是攻击淡褐卷蛾（light brown apple moth，简称LBAM）——桉褐卷蛾（Epiphyas postvittana (Walker)）的最优势寄生性天敌，而桉褐卷蛾是澳大利亚与新西兰地区葡萄藤的主要鳞翅目（Lepidoptera）卷蛾科（Tortricidae）害虫。提升该寄生蜂的替代寄主种群，是推进该害虫保护生物防治的有效途径之一。本研究在实验室条件下，针对该寄生蜂对桉褐卷蛾以及两种相关替代寄主——粗角卷蛾（Acropolitis rudisana (Walker)）和麦宽卷蛾（Merophyas divulsana (Walker)）的寄主搜寻行为展开探究，以评估该防治策略的可行性。所有供试寄主均被该寄生蜂接受，寄生率均高于70%。行为测定结果显示，该寄生蜂对不同寄主物种的响应存在差异，这可能与寄主的物理特征、取食及防御行为差异相关。实验结果表明，粗角卷蛾与麦宽卷蛾这两种替代寄主的存在，可有效提升塔斯曼尼亚长茧蜂的种群数量。在农业景观中保护塔斯曼尼亚长茧蜂种群，对于淡褐卷蛾的保护生物防治至关重要。