The sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) causes economic losses of millions of dollars to agricultural and ornamental crops worldwide through direct feeding and transmission of plant viruses. Bemisia tabaci represents a classic example of a cryptic species as it consists of morphologically indistinguishable biotypes that exhibit considerable variation in host preference, mating behavior, virus transmission ability, and pesticide resistance. However, the evolutionary history and genetic relationships among populations/ biotypes, especially at the global level, are still not well understood. In this study, we used a set of 19 microsatellite loci isolated from B. tabaci in our laboratories and published in the literature to genotype whiteflies from representative locations worldwide. Our preliminary results suggest that there is limited gene flow among populations from different continents, except for the case of invasive populations/ biotypes. Our data provide a detailed picture of genetic structure within and among closely related populations and support the general findings of previous studies that classified biotypes into distinct clades based on mitochondrial DNA sequences. We are currently using microsatellite data to identify historical demographic parameters and invasion patterns of populations/ biotypes of B. tabaci. Our study aims to resolve evolutionary scenarios that have led to the origins, diversification and maintenance of cryptic/ invasive biotypes which will in turn help clarify the systematics, evolutionary history and management of this species complex.