New Synonym and New Species Record of Filchneria (Plecoptera: Perlodidae) from China with a Morphological, Phylogenetic and Biogeographic Study on This Genus

SIMPLE SUMMARY: When the perlodid genus Filchneria Klapálek, 1908 was proposed, F. mongolica (Klapálek, 1901) was designated as the type species, with a female holotype from Mongolia and another collection of male and female from the Qinling Mountains of central China. These specimens from different areas have been mistaken over the past one century. We verified this research history of the two amazing species by updating their morphological descriptions and distribution records. In addition, the genus Sinoperlodes Chen, 2020 recently proposed is proved to be a synonym of Filchneria, with the morphological, biological, phylogenetic and biogeographical issues discussed. ABSTRACT: The type species of Filchneria Klapálek, 1908, F. mongolica (Klapálek, 1901), is based on a single female collected from Mongolia, but it was considered the same as another species, F. songi from Qinling, China, when the genus Filchneria was proposed. This study narrates the story of these two species, which have been confused for a century. Until now, the distribution of F. mongolica has been confirmed only in Mongolia and Russia, and we recently recorded it for the first time in Inner Mongolia as a new species record in China. Additionally, the genus Sinoperlodes is a junior synonym of Filchneria, as demonstrated by both the morphological and molecular analysis. Phylogenetic analysis based on the subfamily Perlodinae is provided, along with morphological and biogeographic comparisons of Filchneria and its relatives.