Next step toward a molecular phylogeny of click-beetles (Coleoptera: Elateridae): redefinition of Pityobiinae, with a description of a new subfamily Parablacinae from the Australasian Region

Elateridae represents one of the largest families within Coleoptera, yet their interrelationships remain under-investigated. Molecular data are missing for most lineages, especially for the species-poor suprageneric taxa. In this study, we investigated the limits and phylogenetic position of Pityobiinae sensu Calder (1996), a group of several small genera from the New World and Australasia, using maximum likelihood and Bayesian inference methods. We merged new sequence data with those deposited in GenBank, producing a final matrix of 178 terminal taxa and covering the main click-beetle subfamilies. The resulting topologies showed Elaterinae as sister to remaining click-beetle lineages, and Agrypninae as sister to the Morostomatinae + Dendrometrinae + Cardiophorinae + Negastriinae clade. Members of Hemiopinae, Lissominae, Thylacosterninae and Pityobiinae formed basal lineages within Elateridae − Elaterinae. We found Lissominae to be polyphyletic, including Thylacosterninae as a terminal lineage and with Oestodini forming an independent lineage outside that clade. Therefore, the subfamily Oestodinae stat. nov. was reinstated for the North American genera Oestodes LeConte and Bladus LeConte. The Australian genera Dicteniophorus Candèze, Drymelater Calder and Stichotomus Candèze were transferred from Dendrometrinae to Elaterinae. Pityobiinae was recovered as two distant lineages in all analyses and correspondingly the subfamily is reduced to contain only the North American Pityobius LeConte and tentatively the South American Tibionema Solier, for which we have no DNA sequences. Additionally, we propose Parablacinae subfam. nov. for the remaining former pityobiine genera from Australia and New Zealand. The new subfamily includes Parablax Schwarz, Metablax Candèze, Wynarka Calder, Xuthelater Calder, Tasmanelater Calder, Parasaphes Candèze and also Ophidius Candèze, which is transferred here from Elaterinae. We failed to find universally diagnostic synapomorphies in adult morphology for Parablacinae, a common problem in elaterid taxonomy. Future research, including a comprehensive phylogeny of the subfamily and re-examination of the morphology of its species is crucial to understanding the limits and classification of this lineage.