Phylogenetic relationships among microgastrine braconid wasp genera based on data from the 16S, COI and 28S genes and morphology

Abstract

Phylogenetic relationships among the genera of the large braconid wasp subfamily Microgastrinae were explored using DNA sequence data from the mitochondrial large ribosomal subunit (16S), nuclear large ribosomal subunit (28S) and mitochondrial cytochrome oxidase (COI) genes, along with morphological characters, both new and from previous studies. The taxonomic history of this group of wasps is reviewed, along with a critique of previous phylogenetic studies on the group. Molecular data were sampled from forty-six species representing twenty-six genera of microgastrines, plus three species representing the close outgroup taxa Cardiochilinae and Miracinae. Some 2300 base pairs of aligned sequence were obtained per taxon from the three genes. In addition, fifty-three morphological characters were coded for all known genera, including two undescribed genera, except Semionis Nixon (known from only a single male type specimen). Relationships among several groups of genera are clarified and challenge some major assumptions made in earlier classifications. In particular, it is clear that dependence on one or a few major morphological character systems oversimplifies relationships, and can lead to misleading results. Despite the large amount of data analysed, basal divergences within the subfamily remain poorly resolved and essentially unsupported in any rigorous statistical sense.