RAPD analysis was used to evaluate the genetic variability of 12 Brazilian populations of Bemisia spp. (Hemiptera: Aleyrodidae). Ten primers were analysed in order to detect the polymorphism between the samples tested. The results showed that individuals from a colony maintained since 1983 had similar patterns of Bemisia tabaci originated from California, USA. The other samples analysed showed similar patterns to B. tabaci biotype B (=B. argentifolii), also from California, USA, indicating a great dissemination of this biotype in Brazil. Phenetic analysis of populations revealed high homogeneity between individuals of the B biotype of B. tabaci.
