Data from: Patterns of host plant utilization and diversification in the brush-footed butterflies

Herbivorous insects represent one of the most successful animal radiations known. They occupy a wide range of niches, feed on a great variety of plants, and are species rich; yet the factors that influence their diversification are poorly understood. Host breadth is often cited as a major factor influencing diversification, and, according to the Oscillation Hypothesis, shifts from generalist to specialist feeding states increase the diversification rate for a clade. We explored the relationship between host breadth and diversification within the Nymphalidae (Lepidoptera) and explicitly tested predictions of the Oscillation Hypothesis. We found strong evidence of diversification rate heterogeneity, but no difference in host breadth between clades with a higher diversification rate compared to their sisters. We also found some clades exhibited phylogenetic non-independence in host breadth and these clades had lower host plant turnover than expected by chance, suggesting host breadth is evolutionarily constrained. Finally, we found that transitions among host breadth categories varied, but the likelihood of reductions in host breadth was greater than that of increases. Our results indicate host breadth is de-coupled from diversification rate within the Nymphalidae, and that constraints on diet breadth might play an important role in the evolution of herbivorous insects.植食性昆虫是目前已知最成功的动物辐射演化类群之一。它们占据广泛的生态位，取食种类繁多的植物，物种多样性极高；然而，影响其物种多样化的关键因素仍鲜为人知。寄主范围常被视为影响类群多样化的核心因素之一，根据振荡假说（Oscillation Hypothesis），从泛食性向专食性取食策略的转变会提升分支的多样化速率。本研究以蛱蝶科（Nymphalidae，鳞翅目Lepidoptera）类群为研究对象，探究其寄主范围与物种多样化之间的关联，并对振荡假说的预测进行了直接检验。研究发现蛱蝶科类群存在显著的多样化速率异质性，但相较于姐妹分支，多样化速率更高的分支其寄主范围并无显著差异。此外，部分类群的寄主范围存在系统发育非独立性，且此类类群的寄主植物更替率低于随机预期水平，表明寄主范围在演化过程中存在约束。最后，本研究发现寄主范围类别的转换频率存在差异，寄主范围缩减的概率高于拓展的概率。本研究结果表明，蛱蝶科类群的寄主范围与多样化速率并无关联，而取食范围的演化约束可能在植食性昆虫的演化历程中发挥着重要作用。