Notes on the identity of Oreodytes dauricus (MOTSCHULSKY 1860) and other members of the O. alaskanus-clade (Coleoptera: Dytiscidae) Author Fery, H. Author P. N Author Alarie, Y. text Linzer biologische Beiträge 2007 2007-07-23 39 1 65 78 journal article 10.5281/zenodo.5412227 0253-116X 5412227 Key to species of the Oreodytes alaskanus -clade The following key to species is based in part on that given in LARSON et al. (2000: 453) . Numbers with an asterisk (*) relate to figures in this work. 1 Male with median lobe in ventral view narrow and subparallel ( Figs 7b , 9b); last but one visible sternum with hind margin straight, lacking a posteromedial lobe. Female with apex of last visible sternum not protruded, but deeply U-shaped in posterior view (Fig. 15). One Palaearctic and one Holarctic species..........................................................2 - Male with median lobe in ventral view broadened subapically and spoon-shaped (Figs 117E*, 117J*); last but one visible sternum with at least a small posteromedial lobe. Female with apex of last visible sternum distinctly protruded and lobed medially (Figs 117C*, 117H*). Nearctic species........................................................................................3 2 Pronotum with posterior angles acute, but moderately produced. Protibia less strongly curved (Figs 11-12). Body shorter (TL: 4.7-5.3 mm ). Male median lobe as in Figs 7 a-c. Species known from the Russian Far East, Alaska ( USA ), and the Yukon Territory ( Canada ).................................................................................. O. dauricus (MOTSCHULSKY) - Pronotum with posterior angles acute and strongly produced. Protibia strongly curved (Figs 13-14). Body longer (TL: 5.0- 5.7 mm ). Male median lobe as in Figs 9a-c. Species known from Mongolia ............................................. O. shorti (SHAVERDO & FERY) 3 Male median lobe moderately broadened subapically, its maximum width less than two times its medial width (Fig. 117E*). Female elytron with subapical tooth obtuse, hind margin behind tooth forming an angle of much less than 90° with suture (Fig. 117A*, 117B*). Species known from southern Alaska , Alberta , and Washington ............................ ............................................................................................................. O. alaskanus (FALL) - Male median lobe strongly broadened subapically, its maximum width two or more times its medial width (Fig. 117J*). Apex of female elytra conjointly truncate, thus, hind margin of elytra and suture forming approximately a right angle (Fig. 117G*, 117H*); subapical tooth more or less right angled. Species known from the Rocky Mountains of western Alberta , south-eastern British Columbia and western Montana ......... ............................................................................................. O. productotruncatus (HATCH)