Direct optimization and multiple alignment of 28S D2-D3 rDNA sequences: problems with indels on the way to a molecular phylogeny of the cryptine ichneumon wasps (Insecta: Hymenoptera)

A molecular phylogeny of the Cryptinae based on the D2–D3 region of the 28S rDNA gene, including 176 cryptines representing 139 genera and an additional 77 outgroup genera, is presented. Direct optimization and multiple alignment each with a range of gap/substitution parameters were employed. The informal higher grouping of the ichneumonids were supported, but the relationship of the Ichneumoninae and Cryptinae was not resolved. Cryptinae tribes were supported but many genera formed constant groups that did not follow earlier subtribal divisions. We investigated artifactual placements of, e.g., Agriotypinae and Brachycyrtinae, and showed that they do not possess molecular synapomophies with the Ichenumoninae where direct optimization places them. The sequences of anomalous placed taxa were markedly longer (or in some cases shorter) than those of most other taxa, and this is explained by homoplastic indels at "hot spots" in the absence of large numbers of informative substitutions. We show that multiple alignment generally resulted in taxa with large insertions or deletions being placed in more plausible positions. The relationship of the genus Alomya is also explored