Data from: Similarity and specialization of the larval versus adult diet of European butterflies and moths

Many herbivorous insects feed on plant tissues as larvae but use other resources as adults. Adult nectaring is an important component of the diet of many adult herbivores, but few studies compare adult and larval feeding for broad groups of insects. We compiled a dataset of larval host use and adult nectar sources for 995 butterfly and moth species (Lepidoptera) in Central Europe. Using a phylogenetic generalized least squares approach, we found that Lepidoptera that fed on more plant species as larvae were also nectar-feeding on more plant species as adults. Lepidoptera that lack functional mouthparts as adults on average used more plant species as larval hosts than Lepidoptera with adult mouthparts. We found that 54% of Lepidoptera include their larval host as a nectar source. By creating null models describing similarity between larval and adult nectar sources, we furthermore show that Lepidoptera nectar on their larval host more than would be expected if they fed at random on available nectar sources. Despite nutritional differences of plant tissue and nectar, we show that there are similarities between adult and larval feeding in Lepidoptera. This suggests that either behavioral or digestive constraints are retained throughout the lifecycle of holometabolous herbivores, affecting host breadth and identity.

许多植食性昆虫在幼虫阶段以植物组织为食，成虫阶段则利用其他类型的营养资源。成虫取食花蜜是多数成年植食性昆虫食谱的重要组成部分，但目前鲜有研究针对多个昆虫大类群比较其成虫与幼虫的取食行为。本研究整合了中欧地区995种鳞翅目（Lepidoptera）昆虫（包括蝶与蛾）的幼虫寄主使用数据与成虫花蜜来源数据。本研究采用系统发育广义最小二乘法（phylogenetic generalized least squares）分析后发现，幼虫阶段取食更多植物种类的鳞翅目昆虫，其成虫阶段取食的花蜜植物种类也更多。成虫阶段缺乏功能性口器的鳞翅目昆虫，其幼虫阶段平均使用的寄主植物种类，要多于成虫阶段具备功能性口器的类群。本研究发现，54%的鳞翅目昆虫会将其幼虫阶段的寄主植物同时作为花蜜来源。通过构建描述幼虫寄主与成虫花蜜来源相似性的零模型（null models），本研究进一步证实，鳞翅目成虫取食幼虫寄主植物花蜜的概率，显著高于随机选取现有花蜜植物的预期概率。尽管植物组织与花蜜的营养组成存在显著差异，本研究仍证实鳞翅目昆虫的成虫与幼虫取食行为存在相似性。这表明，全变态植食性昆虫在整个生命周期中可能保留了行为或消化层面的限制因素，进而影响其寄主范围与寄主种类选择。