One of the most studied and best-known mutualistic relationships between insects is that between ants and phloem-feeding insects. Ants feed on honeydew excreted by phloem-feeding insects and, in exchange, attack the phloem feeders' natural enemies, including parasitic wasps. However, parasitic wasps are under selection to exploit information on hazards and avoid them. Here, we tested whether parasitic wasps detect the previous presence of ants attending colonies of phloem feeders. Behavioural assays demonstrate that wasps left colonies previously attended by ants more frequently than control colonies. This behaviour has a potential cost for the parasitic wasp as females inserted their ovipositor in fewer hosts per colony. In a further bioassay, wasps spent less time on papers impregnated with extracts of the ant cues than on control papers. Gas chromatography coupled with mass spectrometry analyses demonstrated that ants left a blend of cuticular hydrocarbons when they attended colonies of phloem feeders. These cuticular hydrocarbons are deposited passively when ants search for food. Overall, these results suggest, for the first time, that parasitic wasps of honeydew producers detect the previous presence of mutualistic ants through contact infochemicals. We anticipate such interactions to be widespread and to have implications in numerous ecosystems, as phloem feeders are usually tended by ants.

中文翻译：

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寄生蜂通过检测蚂蚁表皮碳氢化合物来避开受蚂蚁保护的半翅目宿主

昆虫之间研究最多和最著名的互惠关系之一是蚂蚁和韧皮部昆虫之间的关系。蚂蚁以韧皮部昆虫分泌的蜜露为食，作为交换，蚂蚁会攻击韧皮部饲养者的天敌，包括寄生蜂。然而，正在选择寄生蜂来利用有关危害的信息并避免它们。在这里，我们测试了寄生黄蜂是否检测到先前存在的蚂蚁进入韧皮部饲养者的群体。行为分析表明，与对照群体相比，黄蜂更频繁地离开先前由蚂蚁观察过的群体。这种行为对寄生黄蜂有潜在的成本，因为雌性将它们的产卵器插入每个菌落的宿主中。在进一步的生物测定中，与对照纸相比，黄蜂在用蚂蚁线索提取物浸渍的纸上花费的时间更少。气相色谱结合质谱分析表明，当蚂蚁进入韧皮部饲养者的群落时，它们会留下表皮碳氢化合物的混合物。当蚂蚁寻找食物时，这些表皮碳氢化合物会被动沉积。总的来说，这些结果首次表明，蜜露生产者的寄生蜂通过接触信息化学物质检测到互惠蚂蚁的先前存在。我们预计这种相互作用会很普遍，并对许多生态系统产生影响，因为韧皮部饲养者通常由蚂蚁照料。蜜露生产者的寄生蜂第一次通过接触信息化学检测到互惠蚂蚁的先前存在。我们预计这种相互作用会很普遍，并对许多生态系统产生影响，因为韧皮部饲养者通常由蚂蚁照料。蜜露生产者的寄生蜂第一次通过接触信息化学检测到互惠蚂蚁的先前存在。我们预计这种相互作用会很普遍，并对许多生态系统产生影响，因为韧皮部饲养者通常由蚂蚁照料。