Molecular phylogeny of Collembola inferred from ribosomal RNA genes.

The classification of taxa within Collembola (Springtails, Hexapoda) has been controversial. In this study, we combined complete 18S rRNA gene with partial 28S rRNA gene (D7-D10) sequences to investigate the phylogeny of Collembola. About 2500 aligned sites of thirty species representing 29 genera from 14 families of Collembola were analyzed, including one species of Neelipleona from which no sequence has been reported previously. The phylogenetic trees were obtained by different methods (maximum parsimony, maximum likelihood, and Bayesian analysis). Our results supported the monophyly of two of the four taxonomic groups of Collembola summarized by Deharveng [Deharveng, L., 2004. Recent advances in Collembola systematics. Pedobiologia 48, 415-433.], namely of Poduromorpha and of Symphypleona. Within Poduromorpha, Neanuridae was monophyletic with high support, but Hypogastruridae was not. Entomobryomorpha was paraphyletic, as the Tomoceroidea (Tomoceridae and Oncopoduridae) was found to be apart from the other entomobryomorphs. In the latter Isotomoidea and Entomobryoidea joined into a group with moderate support. Within Symphypleona, the phylogenetic relationship [(Sminthuridae+Bourletiellidae)+Sminthurididae] was consistent with traditional morphological studies. Neelipleona grouped with Symphypleona in all trees, with moderate support in the ML and Bayesian analyses.