Molecular phylogeny of the sawfly subfamily Nematinae (Hymenoptera: Tenthredinidae)

Abstract

Nematinae is one of the largest subfamilies in the sawfly family Tenthredinidae, but internal relationships are unknown in the absence of any formal phylogenetic analysis. To understand the internal phylogeny of Nematinae, we sequenced a portion of the mitochondrial cytochrome oxidase I gene and the nuclear elongation factor-1α gene from thirteen outgroup taxa and sixty-eight nematine species, the ingroup taxa of which represent all major genera and subgenera within the subfamily. Maximum parsimony and Bayesian phylogenetic analyses of the DNA sequence data show that: (1) Nematinae are monophyletic in a broad sense which includes Hoplocampa, Susana and the tribe Cladiini, which have been classified often into separate subfamilies; together with Craterocercus, these taxa form a paraphyletic basal grade with respect to the remaining Nematinae, but among-group relationships within the grade remain weakly resolved; (2) the remainder of the ingroup, Nematinae s. str, is monophyletic in all combined-data analyses; (3) within Nematinae s. str, the 'Higher' Nematinae is divided into three groups, Mesoneura and the large tribes Nematini and Pristiphorini; (4) although the traditional classifications at the tribal level are largely upheld, some of the largest tribes and genera are obviously para- or polyphyletic; (5) according to rate-smoothed phylogenies dated with two fossil calibration points, Nematinae originated 50-120 million years ago. In addition, the results from all Bayesian analyses provide strong and consistent support for the monophyly of Tenthredinidae, which has been difficult to demonstrate in previous parsimony analyses of morphological and molecular data. © 2006 The Royal Entomological Society.