Argentine stem weevil behavioural responses to different parasitoids

Importation biological control can create novel host-natural enemy associations that exhibit responses different from evolved behaviours in their native range. This possibility was investigated in New Zealand based on the South American pasture pest, the Argentine stem weevil (<em>Listronotus bonariensis</em>) in the presence of three endoparasitoid species with different levels of affinity to the weevil. The first parasitoid was <em>Microctonus hyperodae</em> which has a close coevolutionary history with <em>L. bonariensis</em>. The second, was <em>M.</em> <em>aethiopoides</em> (Irish strain), which has bionomic and ecological overlaps with <em>M. hyperodae</em> and is an effective control agent of the clover root weevil <em>Sitona obsoletus </em>in pasture. The third parasitoid was <em>Aphidius colemani</em> which attacks aphids and is phylogenetically and ecologically remote from the two <em>Microctonus</em> spp. Microcosms were used to examine and compare the nature of the <em>L. bonariensis</em> responses when confronted by each of these parasitoids. Please note some behavioural, plant section by height and feeding scar raw data variables were not analysed. Here <em>M. hyperodae</em>, showed distinctive crouching and reduced feeding behaviour when confronted by <em>M. hyperodae</em>. When exposed to <em>M. aethiopoides</em>, the weevil exhibited very much reduced responses and there was no reaction whatsoever to <em>A. colmani</em>. The implications of these <em>L. bonariensis </em>behavioural responses are discussed in terms of the biogeography of the parasitoid species with reference to possible pre-adaptative behaviour.

引种生物防治可构建全新的寄主-天敌组合，其表现出的行为响应与其在原生分布区的演化行为存在差异。本研究以新西兰为研究区域，以南美牧场害虫阿根廷茎象甲（*Listronotus bonariensis*）为对象，探究了三种对该象鼻虫具有不同亲和水平的内寄生蜂物种的相关效应。第一种寄生蜂为*Microctonus hyperodae*，其与*L. bonariensis*具有紧密的协同演化历史。第二种为*M. aethiopoides*（爱尔兰品系），其与*M. hyperodae*在生物学特性与生态学特征上存在重叠，且可有效防治牧场中的三叶草根象甲*Sitona obsoletus*。第三种寄生蜂为*Aphidius colemani*，其寄主为蚜虫，在系统发育与生态学上与两种*Microctonus*属物种相去甚远。本研究采用微宇宙实验体系，探究并比较了*L. bonariensis*在遭遇上述每种寄生蜂时的行为响应特征。请注意，部分行为学指标、植物高度分区及取食痕的原始数据变量未纳入分析。当遭遇*M. hyperodae*时，*L. bonariensis*展现出独特的蜷缩行为与取食活动减弱的特征；当暴露于*M. aethiopoides*时，该象鼻虫的响应程度大幅降低；而对*A. colemani*则完全无任何反应。本研究结合寄生蜂物种的生物地理学特征，探讨了*L. bonariensis*的上述行为响应的生态学意义，并参考了潜在的预适应行为。