Morphological re-examination of Epiophlebia laidlawi (Insecta: Odonata) including remarks on taxonomy

Epiophlebia is the only known taxon of Odonata that is neither part of the damselflies (Zygoptera) nor dragonflies (Anisoptera). Previously, two species of Epiophlebia were recognized, restricted to areas in Japan (Epiophlebia superstes) and the Himalayas (Epiophlebia laidlawi). Recently, the group gained attention with the description of new species from China – Epiophlebia sinensis and Epiophlebia diana – while a subsequent genetic study suggested only one species of Epiophlebia. To clarify these conflicting hypotheses this study focused on the under-recorded Epiophlebia laidlawi. This study elucidated the morphology of this species in comparison to Epiophlebia superstes, representing the first comparative study of Epiophlebia species. Furthermore, it presents notes on the taxonomic conditions of this group. With this study, a first step is made to resolve the confusion regarding the taxonomic status of the described Epiophlebia species. A number of anatomical characters – for example the different shape of the vertex of the head, the distinct colour patterns of the head, thorax and the abdomen or the differences in the shape of the hamulus anterior and posterior in the secondary male genitalia – confirmed the species status of E. laidlawi and underlined its distinctness from E. superstes. However, in the Chinese species E. sinensis and E. diana a re-examination is advised; especially in E. diana the species status is questionable.