Data from: Host specialisation involving attraction, avoidance and performance, in two phytophagous moth species

Host specialization plays a key role in the extreme diversification of phytophagous insects. Whereas proximate mechanisms of specialization have been studied extensively, their consequences for species divergence remain unclear. Preference for, and performance on hosts are thought to be a major source of divergence in phytophagous insects. We assessed these major components of specialization in two moth species, the European corn borer (ECB) and the Adzuki bean borer (ABB), by testing their oviposition behaviour in different conditions (choice or no-choice set-ups) and their performances, by reciprocal transplant at the larval stage on the usual host and an alternative host plant. We demonstrated that both ABB and ECB have a strong preference for their host plants for oviposition, but that relative larval performances on the usual host and an alternative host differed according to the experiment and the trait considered (weight or survival). Finally, we show for the first time that the preference for maize in ECB conceals a strong avoidance of mugwort. The differences in performance, attraction and avoidance between ECB and ABB are discussed in the light of the underlying mechanisms and divergence process.宿主特化（host specialization）在植食性昆虫（phytophagous insects）的极端物种分化（species divergence）中发挥着关键作用。尽管学界已对宿主特化的近因机制（proximate mechanisms）开展了大量研究，但这些机制对物种分化的影响仍不明晰。对寄主的偏好性以及在寄主上的适应性表现，被认为是植食性昆虫物种分化的主要驱动源之一。本研究以两种蛾类——欧洲玉米螟（European corn borer, ECB）与小豆螟（Adzuki bean borer, ABB）为研究对象，通过设置选择式与非选择式实验装置（choice or no-choice set-ups）检测其产卵行为（oviposition behaviour），并通过在常规寄主植物（usual host plant）与替代寄主植物（alternative host plant）上开展幼虫阶段（larval stage）的互易移植实验（reciprocal transplant），评估二者宿主特化的两大核心组分。研究结果显示，ABB与ECB均对各自的常规寄主植物具有强烈的产卵偏好，但二者在常规寄主植物与替代寄主植物上的相对幼虫适应性表现（larval performance），会因实验设计与所考察的性状（trait，包括体重或存活率）不同而存在差异。尤为关键的是，本研究首次发现，欧洲玉米螟对玉米（maize）的产卵偏好，实则掩盖了其对艾蒿（mugwort）的强烈规避行为。本研究结合潜在作用机制（underlying mechanisms）与物种分化过程（divergence process），对欧洲玉米螟与小豆螟在适应性表现、寄主吸引性与驱避性方面的差异展开了讨论。