Molecular evidence for the subfamilial status of Tetralobinae (Coleoptera: Elateridae), with comments on parallel evolution of some phenotypic characters

Abstract

Tetralobinae is a distinct click-beetle lineage containing 78 species in seven genera. Adults are large-bodied, and larvae live in termite nests and are grub-like unlike typical elaterid wireworms. Their taxonomic position in the Elateridae has been unstable and they were treated either as a separate elaterid subfamily or a tribe within Agrypninae. Here, we provide the first molecular investigation of Tetralobinae to test their phylogenetic position using two nuclear and two mitochondrial molecular markers from three total taxa, one from each of the following genera: Tetralobus Lepeletier & Audinet-Serville, Sinelater Laurent, and Pseudotetralobus Schwarz. Two different datasets were analyzed, Elateridae (181 terminals) and Elateroidea (451 terminals), both composed by the earlier published datasets supplemented with the newly produced tetralobine sequences. The results suggest that Tetralobinae is the sister lineage to the remaining Elateridae and that warrants the subfamilial status instead of an subordinate position in the Agrypninae. Pseudotetralobus (Australia) was sister to the Tetralobus (Africa) + Sinelater (China) consistent with previously published morphological analysis. Additionally, we discuss the homoplastic phenotypic characters which were used for building the earlier click-beetle classification, and which indicated the relationships between Tetralobinae and Agrypninae.