Comprehensive gene and taxon coverage elucidates radiation patterns in moths and butterflies

Abstract

Lepidoptera (butterflies and moths) represent one of the most diverse animals groups. Yet, the phylogeny of advanced ditrysian Lepidoptera, accounting for about 99 per cent of lepidopteran species, has remained largely unresolved. We report a rigorous and comprehensive analysis of lepidopteran affinities. We performed phylogenetic analyses of 350 taxa representing nearly 90 per cent of lepidopteran families. We found Ditrysia to be a monophyletic taxon with the clade Tischerioidea + Palaephatoidea being the sister group of it. No support for the monophyly of the proposed major internested ditrysian clades, Apoditrysia, Obtectomera and Macrolepidoptera, was found as currently defined, but each of these is supported with some modification. The monophyly or near-monophyly of most previously identified lepidopteran superfamilies is reinforced, but several species-rich superfamilies were found to be para- or polyphyletic. Butterflies were found to be more closely related to 'microlepidopteran' groups of moths rather than the clade Macrolepidoptera, where they have traditionally been placed. There is support for the monophyly of Macrolepidoptera when butterflies and Calliduloidea are excluded. The data suggest that the generally short diverging nodes between major groupings in basal non-tineoid Ditrysia are owing to their rapid radiation, presumably in correlation with the radiation of flowering plants.

Figure 1.

Overview of the 350-taxon RAxML maximum likelihood analysis. The tree was rooted on Micropteryx, a taxon likely to be a sister group to all other Lepidoptera. Non-ditrysian clades are all shown in black. Major ditrysian branches are coloured and their content indicated at the superfamily level. Putative ditrysian clades are shown by arrows in the middle of the circle. A solid line indicates complete inclusion and a dashed line partial inclusion in the named clade.

Figure 2.

Cladogram of the Bayesian tree of the 118-taxon subset of ditrysian taxa. Posterior probabilities estimated under the GTR + G model (three BEAST runs of 20 million generations each) are shown above the branches. Ditrysian superfamilies are shown on the right.