Out of the darkness - a new genus of Paederinae from the Neotropics (Coleoptera: Staphylinidae) and its phylogenetic position

We describe a new genus of Paederinae rove beetles, Karillantu gen. nov., which occurs only in the Neotropics. The genus accommodates Lathrobium macrocephalum Sharp, 1876 as a type species Karillantu macrocephalus comb. nov., originally described more than 100 years ago. Intense surveys across museum collections allowed for describing eight new species: Karillantu amazonaensis sp. nov., Karillantu ecuadoriensis sp. nov., Karillantu lauretensis sp. nov., Karillantu napoensis sp. nov., Karillantu obidensis sp. nov., Karillantu paraensis sp. nov., Karillantu pastazaensis sp. nov., and Karillantu peruviensis sp. nov. We provide descriptions of the genus and species, a redescription of Karillantu macrocephalus comb. nov., an identification key, and a distribution map. To determine the sister-group relationships of Karillantu gen. nov., we conducted a phylogenetic analysis based on seven gene fragments, resulting in the largest Paederinae phylogeny up to date and a hypothesis about Karillantu gen. nov. placement. The analysis resolved the genus within the tribe Lathrobiini, nested in the informal clade of genera traditionally assigned to the subtribe Lathrobiina. We also provide information on the phylogenetic position of 17 newly sequenced taxa expanding our understanding of Paederinae relationships. The present research underscores the importance of museum collections in studying biodiversity of poorly-known groups, especially in the tropical regions.