Genetic structure of Aedes albifasciatus (Diptera : Culicidae) populationsin central Argentina determined by random amplified polymorphic DNA-polymerase chain reaction markers

The floodwater mosquito, Aedes albifasciatus (Macquart), is the main vector of western equine encephalomyelitis virus in Argentina. Previous studies o n the genetic structure of this species using allozymes showed low levels o f polymorphism, absence of subpopulations at distinct habitats, and moderat e differentiation among localities separated up to 500 km. To examine gene now using other genetic methods, we analyzed random amplified polymorphic D NA-polymerase chain reaction (RAPD-PCR) polymorphism in 28 presumptive loci of Ae, albifasciatus from 6 populations in central Argentina. Allele frequ encies were estimated assuming that RAPD products segregate as dominants an d that genotype frequencies at those loci are in Hardy-Weinberg equilibrium . Expected heterozygosity ranged between 0.19 and 0.31, approximate to 3 ti mes the value obtained on the basis of the16 allozymic loci studied previou sly. Four of the populations formed a single panmictic unit. Allele frequen cies in populations occupying different phytogeographic regions gave signif icant F-ST values at 5 loci. Effective migration rates among populations es timated from F-ST ranged from 2.3 to 9.0. The results support the existence of a north-south dine.