To be or not to be a subspecies: description of Saperdapopulnealapponica ssp. n. (Coleoptera Cerambycidae) developing in downy willow (Salixlapponum L.)

摘要

A new subspecies of the European cerambycid Saperda populnea (Linnaeus, 1758) is described: Saperda populnea lapponica >ssp. n. based on specimens from Scandinavia. The male genitalia characters were examined and found to provide support for this separation, as well as differences in morphology, geographical distribution and bionomy. The preferred host tree for the nominate subspecies S. populnea populnea is Populus tremula L., whereas S. populnea lapponica >ssp. n. is considered to be monophagous on Salix lapponum L. DNA sequence data of mitochondrial cytochrome oxidase subunit I (COI) was generated from Scandinavian specimens of S. populnea populnea and specimens representing S. populnea lapponica >ssp. n. The two subspecies were not reciprocally monophyletic and genetic distances in COI were small. All synonyms of S.populneapopulnea have been considered, and species similar to S.populneapopulnea have been examined, and not found to be related to S.populnealapponica>ssp. n. A male lectotype has been designated for each of the two following synonyms: Cerambyxdecempunctatus De Geer, 1775, and Saperdasalicis Zetterstedt, 1818. The synonymised species from Asia, S.balsamifera (Motshulsky, 1860), is elevated to subspecies: S.populneabalsamifera>stat. n. We end with a discussion on the definition of subspecies under the unified species concept.