Genomic evidence suggests Mesapamea remmi is an imaginary species (Lepidoptera: Noctuidae)

Taxonomic status of the noctuid moth Mesapamea remmi Rezbanyai-Reser (Lepidoptera) has remained controversial since its description in 1985. Based on morphology, it has been considered a valid species or a hybrid between Mesapamea secalis (Linnaeus) and Mesapamea didyma (Esper). We studied this case of uncertain identity by using traditional Sanger sequencing techniques (COI and seven nuclear genes) as well as double digest restriction-site associated DNA (ddRAD) sequencing, which resulted in analyses including 9402 loci and 1 512 976 bp across the genome. Our analyses showed that genomic data do not support the hybrid hypothesis and that M. remmi is not separated genetically from M. secalis; both are clearly distinct from M. didyma. Reproductive organs of M. remmi males are unique and diagnosable, whereas females are teratological in the sense that ductus seminalis is missing and corpus bursae is malformed, the latter being connected directly to the ovipore. These data support the view that M. remmi is not a valid species and we consider M. remmi Rezbanyai-Reser, 1985 to be a junior synonym of M. secalis (Linnaeus, 1758). We demonstrate that genomic approaches provide an efficient way to address various difficult and long-standing taxonomic issues, in this case oversplitting of species.