On the phylogenetic status of Contortylenchus genitalicola Kosaka & Ogura, 1993

Summary Contortylenchus genitalicola is a unique species within the genus. It parasitises the ovary or testis of the longhorn beetle, Monochamus alternatus, and has a neotylenchid-like culturable mycetophagous phase within its life cycle, while the other species in the genus parasitise bark beetles and have a typical unculturable allantonematid life cycle. Because the species was described based solely on morphology, it was necessary to confirm the phylogenetic and taxonomic status of C. genitalicola. A molecular phylogenetic analysis of the species based on ribosomal RNA sequences revealed that C. genitalicola forms a well-supported clade with Contortylenchus spp. isolated from bark beetles, an unidentified allantonematid from Iran, and ‘Deladenus cf. laricis’ isolated from the metallic wood-boring beetle, Agrilus macer LeConte (Coleoptera: Buprestidae), in the USA. The generic status of C. genitalicola was supported by phylogenetic analysis, and the analysis also suggests that the diversity of the genus could be higher than currently expected.