World review of Laricobius (Coleoptera: Derodontidae)

Abstract

The Holarctic genus Laricobius (Derodontidae) is reviewed and a key to the species provided. There are 21 known species and those with known life history are predators of adelgids. The type specimen of L. minutus Nikitsky was lost prior to this study and types of L. caucasicus Rost were never located, though one specimen which lacks the abdomen is attributed to this species. One new species is described (Laricobius naganoensis n. sp.) and lectotypes were designated for L. erichsonii Rosenhauer and L. sahlberg Reitter. Europe has one described species, North America 3, and Asia 17. A cladistic analysis, based on 20 species, resulted in two broad groups, one which is confined to south-eastern Asia and Himalaya and has more shortened species with a narrower pronotum lacking explanate margins, and a more widespread Holarctic group, which is more typical of the genus type, being more elongate, with a transverse, fully explanate pronotum. The latter group includes four Asian species without ocelli, collected from Tsuga (hemlock) infested with Adelges tsugae Annand.