A molecular phylogeny of Noctuini (Lepidoptera: Noctuidae: Noctuinae)

Abstract

The tribe Noctuini is comprised over 520 species; many are economically important species that impact human agriculture. Despite their diversity and relevance, relationships of Noctuini have been difficult to resolve. There have been extensive morphological revisions of some of these taxa (e.g., Agrotis Ochsenheimer, Euxoa Hübner); however, there are no studies that focus exclusively on the phylogenetic relationships of the Noctuini. Currently, Noctuini are separated into 2 subtribes, Agrotina and Noctuina. In this study, we tested previous classification schemes with 2 analyses. The total evidence analysis utilized 3 loci for 3 outgroup taxa and 54 noctuine species. Using museum specimens, we collected data from cytochrome oxidase I (COI), Dopa Decarboxylase (DDC), and Elongation factor 1-α (EF1-α) to generate a dataset of 1,378 base pairs (bp) for a total evidence approach. We also used previously published COI sequences for 626 species, resulting in a matrix of 690 bp, termed “the barcode analysis.” We used both Maximum Likelihood and Bayesian approaches for the total evidence analysis, and ML for the barcode analysis. In both sets of results, we found equivocal support for monophyletic Agrotina and Noctuina. We found strong support for smaller, well-described genera (e.g., Spaelotis), but poor support for large genera such as Euxoa, Feltia Walker, and Agrotis. It is likely that a combination of limited taxon/gene sampling, limited gene choice, and the rapid evolution of these species resulted in a lack of phylogenetic resolution in the total evidence topologies. Based on these results, we recommend increased taxon sampling and inclusion of loci that target these rapidly evolving lineages to achieve a better understanding of the phylogeny of Noctuini and its genera.