THE HOLARCTIC SPECIES OFAGABUS(SENSU LATO) LEACH (COLEOPTERA: DYTISCIDAE)

Abstract

The taxonomy, distribution, and ecology of the Holarctic species ofAgabus(Coleoptera: Dytiscidae) are reviewed. Seventeen species occur in both the Nearctic and Palaearctic regions. The following new synonymy is proposed (valid name given last):A. solusLeech =A. adpressusAubé;A. sharpiJacobson andA. pseudoconfertusWallis =A. opacusAubé;A. kenaiensisFall =A. wasastjernae(Sahlberg) andA. hudsonicusLeech =A. zaitzewiPoppius, thus each of these species is recognized for the first time as being Holarctic. The Nearctic speciesA. ontarionisFall is reduced in status to a subspecies ofA. fuscipennis(Payk.).Agabus congener(Thunb.) is redefined and Nearctic specimens formerly placed in the species are assigned toA. thomsoni(J. Sahlberg). The reports of Palaearctic occurrence ofA. approximatesFall andA. discolor(Harris) are considered to be in error, the records referring toA. levanderiHellén.