Taenionema umatilla Stanger & Baumann

(Figs. 65, 66, 67, 76, 77, 86, 98, 111)

Distribution. Idaho, eastern Oregon.

Material examined. Oregon: Umatilla Co., Meachum Creek, Hwy 84 bridge at Meachum (type locality), 1- IV-1983, 1♀ larva, K.W. Stewart (stream iced over); 26-IV-2004, 1♂, 1♀, 1 reared ♂ with exuvium, 2 reared ♀ with exuvia, 2♀ larvae, K.W. Stewart & B. Armitage.

Characters. Color, pigmentation, maxillae, body, leg, and cercal (Figs. 66, 67) setation, and sexual dimorphism (Figs. 65, 76, 77) generally typical of genus. Body length (♂ exuvium) 8.5 mm, ♀ 9 mm. Antennal segments 56-58. Cercal segments undetermined (broken). Male 9 th sternum (Fig. 98) wide behind greatest width and broadly rounded (nearly truncate) apically. Female 9 th sternum (Fig. 111) narrowly triangulate in apical half with narrowly rounded apex.