A survey of Anopheles mosquitoes was undertaken in Putumayo, southern Colombia, to clarify the identity of specimens classified as Anopheles (N) evansae in the region. Female anophelines were captured on human bait; then blood fed on small mammals to obtain eggs for progeny broods. Morphological characteristics of the eggs. larvae, pupae and adults of both sexes, including male genitalia were examined. Eggs were obtained from 247 females provisionally identified as A. (N.) evansae Morphology of associated life stages of the progeny broods was compared among 27 families. The morphology of al1 stages corresponded to the published descriptions of Anopheles (N.) benarrochi. However, morphologically variable adult females were noted. In hind tarsomere 2, the dark portion ranged from 0.17 to 0.33 of the tarsomere length; this is less than previously reported for A. (N) benarrochi and overlaps the ranges described for A. (N,) oswaldoi and A. (N) evansae This variable character probably has led to incorrect identifications of adult A. (N.) benarrochifemales as A. (N.) evansae or A. (N.) oswaldoi in specimens from southern Colombia. As a consequence, A. (N) benarrochi has not been previously recognized in Putumayo, and probably has been misidentified in other areas of northwestern South America.