Evolution and diversity of cuticular hydrocarbon profiles in cleptoparasitic and parasitoid cuckoo wasps and their significance for chemical mimicry

昆虫的角质层上覆盖着一层蜡质，以防止干燥。这些蜡的非极性部分是角质碳氢化合物(CHC)。它们在大多数物种之间是不同的，而且往往在性别之间也不同，昆虫将它们用作线索和信号。考虑到CHC对昆虫的重要性，令人惊讶的是，人们对CHC谱是如何进化的知之甚少。到目前为止，很少有研究发现昆虫的CHC曲线与环境因素(如温度和湿度)之间存在潜在的相关性。我们的研究项目旨在阐明达尔文对雌性的积极选择以模拟其寄主的CHC谱是否是驱动一组寄生和寄生昆虫的CHC谱进化的主要力量：杜鹃黄蜂(膜翅目：金蜂科)。我们将行为实验与基于系统发育的统计分析相结合，比较了杜鹃黄蜂及其远亲宿主的CHC谱。这些行为实验旨在证明宿主-寄生虫的CHC图谱相似性是否与宿主对寄生虫和寄生虫的行为存在因果关系。我们的研究结果将首次对寄生昆虫的CHC谱的延展性和适应性进行量化。

The cuticle of insects is coated with a layer of waxes that serves as protection against desiccation. The non-polar fraction of these waxes are cuticular hydrocarbons (CHCs). These differ between most species and often between sexes, and insects use them as cues and signals. Given the importance of CHCs for insects, it surprises that very little is known about how CHC profiles evolve. So far, few studies have found a potential correlation between CHC profiles of insects and environmental factors, such as temperature and moisture. Our research project aims to elucidate whether or not positive Darwinian selection on females to mimic the CHC profile of their host is a major force that drives the evolution of CHC profiles in a group of cleptoparasitic and parasitoid insects: cuckoo wasps (Hymenoptera: Chrysididae). We combine behavioral experiments with a phylogeny-based statistical analysis that compares CHC profiles of cuckoo wasps and their distantly related hosts. The behavioral experiments are meant to demonstrate whether or not host-parasite CHC profile similarity is causally interrelated with the host’s behavior against cleptoparasites and parasitoids. The results of our research will for the first time allow for quantification of the malleability and adaptability of CHC profiles in parasitic insects.