Anthropogenic host plant expansion leads a nettle-feeding butterfly out of the forest: consequences for larval survival and developmental plasticity in adult morphology

Recent anthropogenic eutrophication has meant that hostplants of nettle-feeding insects became quasi-omnipresent in fertile regions of Western Europe. However, hostplant resource quality – in terms of microclimate and nutritional value – may vary considerably between the ‘original’ forest habitat and ‘recent’ agricultural habitat. Here, we compared development in both environmental settings using a split-brood design, so as to explore to what extent larval survival and adult morphology in the nettle-feeding butterfly Aglais urticae are influenced by the anthropogenic environment. Nettles along field margins had higher C/N-ratios and provided warmer microclimates to larvae. Larvae developed 20% faster, and tended to improve their survival rates, on the agricultural land compared to woodland. Our split-brood approach indicated plastic responses within families, but also family effects in the phenotypic responses. Adult males and females had darker wing pigmentation in the drier and warmer...近年来的人为富营养化（anthropogenic eutrophication）使得取食荨麻的昆虫的寄主植物在西欧肥沃区域近乎无处不在。然而，从微气候（microclimate）与营养价值维度来看，原生森林生境与新近形成的农业生境之间的寄主植物资源质量可能存在显著差异。本研究采用裂群实验设计（split-brood design）对比两种生境下的昆虫发育情况，旨在探究人为环境对取食荨麻的蛱蝶——荨麻蛱蝶（Aglais urticae）的幼虫存活率与成虫形态特征的影响程度。田埂边缘的荨麻碳氮比（C/N ratio）更高，且可为幼虫提供更为温暖的微气候环境。与林地生境相比，农田生境中的幼虫发育速度快20%，且存活率呈上升趋势。本裂群实验设计结果显示，家系内部存在表型可塑性响应，同时表型响应亦存在显著家系效应。在更干燥温暖的环境中，成虫雌雄个体的翅色素沉着均更深……