Intraguild predation is the killing and consuming of a heterospecific competitor that uses similar resources as the prey, and also benefit from preying on each other. We investigated the foraging behaviour of the gallmidge, Aphidoletes aphidimyza, a predator of aphids used for biological control that is also the intraguild prey for most other aphid natural enemies. We focus on how aphid alarm pheromone can alter the behaviour of the gallmidge, and predation by the anthocorid bug Orius laevigatus (O. laevigatus). We hypothesised that gallmidges would respond to the presence of (E)-β-farnesene (EBF) by leaving the host plant. Since feeding by Aphidoletes gallmidge larvae does not induce EBF emission by aphids, this emission indicates the presence of an intraguild predator. We found that gallmidge larvae reduced their foraging activities and left the plant earlier when exposed to EBF, particularly when aphids were also present. Contrastingly, gallmidge females did not change the time visiting plants when exposed to EBF, but lay more eggs on plants that had a higher aphid density. Lastly, EBF reduced the number of attacks of the intraguild predator, O. laevigatus, on gallmidge larvae, potentially because more gallmidges stopped aphid feeding and moved off the plant at which point O. laevigatus predated on aphids. Our work highlights the importance of understanding how intraguild predation can influence the behaviour of potential biological control agents and the impact on pest control services when other natural enemies are also present.

中文翻译：

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蚜虫警报信息素改变捕食性瘿蚊的幼虫行为，蚜虫蚜虫并减少花环虫，Orius laevigatus 的内部捕食

公会内部捕食是杀死和消耗与猎物使用相似资源的异种竞争者，并从相互捕食中受益。我们调查了瘿蚊的觅食行为，蚜虫，一种用于生物防治的蚜虫捕食者，也是大多数其他蚜虫天敌的内部猎物。我们专注于蚜虫警报信息素如何改变瘿蚊的行为，以及花甲虫的捕食黄鹂(O. laevigatus）。我们假设胆蠓会对（乙)-β-法呢烯 (EBF) 离开寄主植物。自从喂了蚜虫瘿蚊幼虫不会诱导蚜虫排放 EBF，这种排放表明存在公会内捕食者。我们发现，当暴露于 EBF 时，gallmidge 幼虫减少了它们的觅食活动并更早地离开植物，特别是当还存在蚜虫时。相比之下，雌性瘿蚊在暴露于 EBF 时并没有改变访问植物的时间，而是在蚜虫密度较高的植物上产下更多的卵。最后，EBF 减少了公会内掠食者的攻击次数，O. laevigatus，在瘿蚊幼虫上，可能是因为更多的瘿蚊停止了蚜虫的摄食并在此时离开植物O. laevigatus早于蚜虫。我们的工作强调了了解内部捕食如何影响潜在生物控制剂的行为以及当其他天敌也存在时对害虫控制服务的影响的重要性。