Diversification dynamics and larval feeding patterns of sack-bearer moths (Lepidoptera: Mimallonidae)

Mimallonidae moths are restricted to the Americas and are known to be closely associated with the plant order Myrtales. Although a dated phylogeny of Myrtales has been published, a dated phylogeny of Mimallonidae is lacking. Therefore, this study infers the first dated phylogeny of Mimallonidae, comparing the timing of diversification of these moths to the dated phylogeny of Myrtales. The diversification dynamics of Mimallonidae are also investigated in order to determine if there are any notable shifts in diversification rate in the evolutionary history of the family, we also investigate if known food plant associations of mimallonids are correlated with diversification. In our dated phylogeny, we infer an exceedingly long branch subtending the crown of the family; this observation mirrors a similar evolutionary pattern in the Myrtales family Combretaceae, which is shown to be one of the most important food plant families for mimallonids. Furthermore, state-dependent diversification models strongly support that food plant associations in Mimallonidae are associated with diversification. We find evidence that shifting away from an ancestral Myrtales feeding condition has increased diversification in these moths. In other words, conserved ancestral feeding on Myrtales may have acted to impede diversification of mimallonids for the past 50 or so million years. This realization may help us to understand the massive disparity of diversity in Mimallonidae (300 species) when compared to their sister group, the Macroheterocera (over 74,000 species).