title: A new species of Labiobaetis Novikova & Kluge, 1987 (Ephemeroptera: Baetidae) from Washington, USA.
abstract: Labiobaetis sonajuventus n.sp. is described from nymphs collected in a tributary of the Okanogan River in north-central Washington, USA. The new species is distinguished from North American congeners by the well-developed keel between the bases of the antennae, the concave lateral margin of labial palp segment 2, the apically expanded submarginal setae on the labrum, and its western Nearctic distribution.
authors.affiliation: Rhithron Associates, Inc., 33 Fort Missoula Road, Missoula, MT, USA 59804; Email: jwebb@rhithron.com.
authors.forename: J M
authors.initials: JM
authors.lastname: Webb
mesh_terms: D063147:Animal Distribution; D000825:Animal Structures / Q000033:anatomy & histology; D000818:Animals; D007313:Insecta / Q000033:anatomy & histology / Q000145:classification*; D014861:Washington