Oulema septentrionis and O. erichsonii are neither conspecific nor melanic variants of O. melanopus as assessed by micro CT analysis of their lectotypes (Insecta, Coleoptera, Chrysomelidae, Criocerinae)1

: The investigation of the type series of Oulema septentrionis (Weise, 1880) and Oulema erichsonii (Suffrian, 1841) using Micro-computed X-ray tomography (µCT) revealed that neither species is a melanic variant of Oulema melanopus (Linnaeus, 1758) as has been suggested previously. Lectotypes of Oulema septentrionis (Weise, 1880) and Oulema erichsonii (Suffrian, 1841) are designated based on the study of type material. The male genitalia of O. septentrionis and O. erichsonii differ to an extent in the shape of the median lobe and flagellum that their status as separate species is - cautiously - confirmed by the present study.