title: Two new species of the megadiverse lentic diving-beetle genusHydrovatus(Coleoptera, Dytiscidae) described from NE Thailand.
abstract: Here we describe two newHydrovatusspecies (Coleoptera: Dytiscidae: Hydroporinae: Hydrovatini) from the province of Khon Kaen, Isan region in NE Thailand.Hydrovatusis the third most species rich genus of diving beetles (Dytiscidae). It occurs on all continents except Antarctica and now numbers 210 currently recognized species. Both new species,Hydrovatus diversipunctatussp. n.andHydrovatus globosussp. n., were collected at lights and are only known from the type locality "Khon Kaen" (a city and province). Diagnoses based on morphology for the separation from closely related species are given together with illustrations of male genitalia and habitus photos. We provide a determination key to Old World species of thepustulatusspecies group and to Oriental species of theoblongipennisspecies group.
authors.affiliation: Finnish Museum of Natural History, Zoology Unit, PB 17, FI-00014 University of Helsinki, Finland.
authors.forename: Olof
authors.initials: O
authors.lastname: Biström
authors.affiliation: Swedish Museum of Natural History, Department of Zoology, Box 50007, SE-10405 Stockholm, Sweden.
authors.forename: Johannes
authors.initials: J
authors.lastname: Bergsten
keywords: Coleoptera; Dytiscidae; Hydrovatus; Thailand; keys to species; new species; taxonomy