A third Neotropical species of the genus Docosia Winnertz is described from the Colombian Andes. Three males and four females of D. adusta sp. nov. from Cundinamarca, Colombia, collected at 3600 m elevation were examined. Detailed illustrations of the male and female terminalia are presented and morphological differences in relation to those of other species of the genus are discussed. The relationships between Holarctic and Neotropical species within Docosia are discussed and overlap of circumantarctic, tropical, and Nearctic elements in the northern Andes is considered.