A genetic study of the malaria vector Anopheles nuneztovari from western Venezuela.

A photomap of larval polytene chromosomes of Anopheles nuneztovari (population B) from western Venezuela is presented. Samples of An. nuneztovari B taken from 4 study sites in the states of Barinas and Táchira comprise a single panmictic population, which is chromosomally identical to the cytotype identified by Kitzmiller et al. (1973) from western Venezuela and Colombia. The frequency of polymorphism 2La has increased significantly in the 16 years that have elapsed since the 1973 study. In addition, inversion 2La does not conform to Hardy-Weinberg equilibrium. These 2 changes are most likely due to environmental alterations which have resulted in the heterozygous condition becoming more locally adaptive.