Morphological, molecular, and chromosomal discrimination of cryptic Anopheles (Nyssorhynchus) (Diptera: Culicidae) from South America.

Abstract

Based on similarity of male genitalia, the malaria vector Anopheles trinkae Faran from the eastern Andean piedmont of Colombia, Ecuador, Peru, and Bolivia was determined by Peyton (1993) to be a junior synonym of An. dunhami Causey, then known from a single locality in Amazonian Brazil. Following an appraisal of molecular, chromosomal, and morphological characters, we conclude herein that the 2 taxa are specifically distinct and remove An. trinkae from synonymy with An. dunhami. Eggs of the 2 species are distinguished easily by the anterior crown, long floats, and closed deck that occur only in An. trinkae. The X chromosome of larval polytenes is divisible into R and L arms in An. dunhami, but not in An. trinkae. A phenogram based on banding pattern scores from 18 random amplified polymorphic DNA primers separated with 100% resolution An. dunhami, An. trinkae, Anopheles nuneztovari Gabaldón and Anopheles darlingi Root. In the ITS2 region of rDNA, 25% of base sites distinguished An. trinkae from An. dunhami and 21% from the related An. nuneztovari; males of these 3 species had accessory glands of significantly different sizes. Preliminary isoenzyme screening indicated that 3 of 11 loci were diagnostic for separating An. trinkae from An. dunhami. The results indicate that An. dunhami is related more closely to An. nuneztovari than to An. trinkae and illustrate the merits of a multidisciplinary approach to mosquito systematics.