Tsetse flies (Glossina spp) constitute and important and widespread block to economic development in much of sub-Sahara Africa because they are the vectors of African sleeping sickness of humans and nagano of cattle. Virtually nothing is known of their population genetics. Although all tsetse have low reproduction rates (probably the least of all insects), the populations are highly resilient and control measures have proven ineffective except against geographically marginal populations. Genetically based methods of tsetse control have long been advocated and work is proceeding on several fronts. Will cultured, release tsetse disperse and mate with their feral cousins? Are there genetically differentiated natural populations of tsetse among which gene flow is greatly reduced or altogether lacking? Are there cryptic species? We propose to measure the extent of genetic variation at the DNA level in the Morsitans species group of tsetse and partition spatially that estimates effective dispersal rates at micro to macro geographical scales. Thus we would achieve estimates of gene flow within and among tsetse populations and sub-populations. The project would provide indices of reproductive isolation, gene flow, and genetic differentiation among conspecific tsetse populations in the southern African and East African fly belts. Genetic markers based on nuclear DNA sequences (microsatellite loci), maternally inherited markers in mtDNA, and allozyme loci will be used to provide the genotypes of individual flies in demes. The data would allow inferences to be drawn about the susceptibility of tsetse to methods of control that depend on matings between cultured and released forms with flies in natural population, e.g., sterile males and transgencic files.
