Click Beetle Mitogenomics with the Definition of a New Subfamily Hapatesinae from Australasia (Coleoptera: Elateridae)

Simple Summary The classification of click beetles is revisited with newly sequenced mitochondrial genomes of eight species belonging to seven different subfamilies. The genus Hapatesus Candeze, 1863, is herein excluded from Dentrometrinae and designated as a type genus of Hapatesinae, a new subfamily. Phylogenetic analyses suggest that Eudicronychinae is a terminal lineage in Elaterinae. Consequently, we propose Eudicronychini, a new status. The deep mtDNA-based split between Elaterinae and the clade of other click beetle subfamilies agrees with the results of phylogenomic analyses and mitochondrial genomes provide a sufficient signal for inference of shallow splits. Elateridae is a taxon with very unstable classification and a number of conflicting phylogenetic hypotheses have been based on morphology and molecular data. We assembled eight complete mitogenomes for seven elaterid subfamilies and merged these taxa with an additional 22 elaterids and an outgroup. The structure of the newly produced mitogenomes showed a very similar arrangement with regard to all earlier published mitogenomes for the Elateridae. The maximum likelihood and Bayesian analyses indicated that Hapatesus Candeze, 1863, is a sister of Parablacinae and Pityobiinae. Therefore, Hapatesinae, a new subfamily, is proposed for the Australian genera Hapatesus (21 spp.) and Toorongus Neboiss, 1957 (4 spp.). Parablacinae, Pityobiinae, and Hapatesinae have a putative Gondwanan origin as the constituent genera are known from the Australian region (9 genera) and Neotropical region (Tibionema Solier, 1851), and only Pityobius LeConte, 1853, occurs in the Nearctic region. Another putative Gondwanan lineage, the Afrotropical Morostomatinae, forms either a serial paraphylum with the clade of Parablacinae, Pityobiinae, and Hapatesinae or is rooted in a more terminal position, but always as an independent lineage. An Eudicronychinae lineage was either recovered as a sister to Melanotini or as a deep split inside Elaterinae and we herein transfer the group to Elaterinae as Eudicronychini, a new status. The mitochondrial genomes provide a sufficient signal for the placement of most lineages, but the deep bipartitions need to be compared with phylogenomic analyses.

Automated summary

The study revisited the classification of click beetles by sequencing mitochondrial genomes of eight species, proposing new subfamilies and transferring groups to new statuses. The deep splits between different subfamilies were supported by phylogenetic analyses using mitochondrial genomes. The results suggest a Gondwanan origin for certain lineages within Elateridae.