Diagnostic allozymes for routine identification of adults of theAnopheles gambiaecomplex (Diptera, Culicidae)

Abstract

Natural populations of four species of the Anopheles gambiae complex occurring in southern Africa were sampled and individuals identified using ovarian polytene chromosomes (19 species A, 190 species B, 140 species C and 54 A. merus Dön.). The genotypes of these same insects were scored for three loci coding for non-specific esterases, and one locus coding for tetrazolium oxidase, after electrophoresis. There is no intra-specific variation at the tetrazolium oxidase locus; species A, B and C share a common allozyme and A. merus is unique. The relative gene frequencies for the 16 allozymes of the three esterase loci for each species give a minimum probability of correct identification of 0·9533 under the worst conditions of sampling, i.e., where samples consist of equal mixtures of species. In practice, resort to such probabilities is necessary only in the discrimination between species A and C. This system of identification is superior to the chromosome method because all adults, whether male or female, and at whatever stage of the gono-tropic cycle, are identifiable.