Toward a natural classification of opatrine darkling beetles: comparative study of female terminalia

The opatrine darkling beetles (Coleoptera: Tenebrionidae: Opatrini) are a worldwide radiation of ~1200 described species, with many more still awaiting discovery. This paper presents results of the first comparative morphological study of the female terminalia of this group. The structure of ovipositor and female genital tubes proved to be extremely useful for delimiting phylogenetic relationships within Opatrini. The following new lineages are recovered: Opatrum (basal parts of paraprocts equipped with claws constituted of baculi) and Sclerum (middle part of coxites soft and extended, apical lobe small and located laterally) generic complexes. Moreover, the analysis revealed that Heterotarsini and Heterocheirini share a unique vagina modification (presence of dual sclerites). Based on this observation, Heterocheirini is placed as a synonym of Heterotarsini. An additional comparative analysis of chosen external characters was performed to test hypotheses mentioned above. This investigation not only supports the conclusions derived from the female reproductive system analysis ( Opatrum and Sclerum generic complexes; homogeneity of Heterotarsini and Heterocheirini), but also leads to the recovery of other presumably monophyletic groups (e.g., Blapsitnus generic complex). Finally, to test the explicitness of the current autapomorphy and determine the status of the whole studied group, a comparative morphological analysis of protrochanters among different tribes of Tenebrioninae was performed. All opatrine genera exhibit a unique protrochanter structure, which is characterized by the elongate base. This feature is unique for Opatrini among Tenebrioninae. Based on the above-mentioned results, the subtribal classification of the Opatrini is revised. Seven following subtribes are recognized: Ammobiina stat. restit. , Blapstinina stat. restit. , Heterotarsina (=Heterocheirini syn. nov. ), Neopachypterina, Opatrina, Sclerina stat. restit. and Stizopina. Additionally, Wolladrus nom. nov. is proposed as a replacement name for Hadrus (Opatrini), which is a junior homonym of a dipteran genus.