Abstract
Nosema leptinotarsae Lipa, 1968 is a microsporidian pathogen of the Colorado potato beetle, Leptinotarsa decemlineata Say. (Coleoptera: Chrysomelidae). To determine the phylogenetic status of N. leptinotarsae, the 16S SSU rRNA gene was sequenced (GenBank Accession No. MN841279) and compared phylogenetically against 21 microsporidian 16S SSU rRNA sequences using neighbour-joining and maximum-parsimony methods. The per cent identities of the N. leptinotarsae and other members of the Nosema-Vairimorpha clade ranged from 78.1 to 98.5%. Pairwise phylogenetic distances between the N. leptinotarsae and other species ranged from 0.009 to 0.320. Phylogenetic analysis shows clearly that N. leptinotarsae is a member of the Vairimorpha clade rather than the Nosema clade. The sequence divergence and morphological traits separated the N. leptinotarsae from other species in the Vairimorpha complex. As a result, a new assignment of Vairimorpha leptinotarsae comb. nov. has been implemented for N. leptinotarsae according to the phylogenetical positioning in the present study.