Genotypic relationships and phylogeography of the genus Oscheius (Rhabditidae: Rhabditomorpha) with a new entomopathogenic isolate of Oscheius tipulae Lam and Webster, 1971

Abstract

Purpose Oscheius tipulae has attracted attention of researchers due to its entomopathogenic character besides serving as a good model for studying development, behaviour, and host-parasite interactions. The main aim of the study is to describe a new isolate O. tipulae first time from India. The study also resolved the exact status of the two species viz., O. siddiqii and O. niazensis described by Tabassum and Shahina (2010) from Pakistan. Methods The relationship of the new isolate with congeners was ascertained by D2/D3-based phylogenetic analysis. A haplotype network was also constructed along with the phylogeography of the taxa to evaluate the degree of divergence within the species, and their worldwide distribution. To examine the congruency between morphological and molecular traits, a morphology-based phylogenetic tree was also constructed. Results The present paper deals with the integrative approach of taxonomy of O. tipulae reported first time from India. The new isolate of O. tipulae extracted from darkling beetle (Tenebrionidae), from Jammu and Kashmir was re-described using morphological and molecular data. The study also revealed that the species O. siddiqii Tabassum and Shahina, 2010 and O. niazensis Tabassum and Shahina, 2010 are similar and close to O. shamimi Tahseen and Nisa, 2006 except the dissimilar lip morphology of O. niazensis Tabassum and Shahina, 2010 which needed reconfirmation based on the type specimens.