To the knowledge of the genus Coloradoa Wilson, 1910 (Hemiptera: Aphididae)

Coloradoa ajaniae Kadyrbekov sp. n. from host plant Ajania fastigiata (C. Winkl.) Poljak. is described from Kazakhstan. New species is similar to C. mesasiatica Kadyrbekov, 2004 but differs from latter by ratio of setae on 8th tergite to the diameter of 3rd antennomere near base (1.0–1.3 vs 0.8–1.0), by ratio of terminal processes to width of the head between eyes (0.27–0.36 and 0.33–0.55, respectively), by number of setae on 8th abdominal tergite (6–8 vs 8–10), and by host plant genus (Ajania vs Artemisia). New synonymy are proposed: Coloradoa brevipilosa (Ivanovskaja, 1958) = Coloradoa huculaki Szelegiewicz, 1981, syn. n., Coloradoa viridis (Nevsky, 1929) = Coloradoa nodulosa Zhang et Zhong, 1980, syn. n. A key to species of genus Coloradoa Wilson, 1910 is compiled.