Genetic analysis of bed bug infestations and populations.

Populations of the common bed bug Cimexlecturaliusare undergoing a huge resurgence, but little is known about their patterns of spread and dispersal. We have begun to address this information gap by conducting population genetic studies of bed bug infestations in the U.S. using microsatellite markers and mtDNA sequence data. In addition, we investigated the frequency of insecticide resistance (kdr) alleles in the U.S. Across 17 populations from the eastern U.S., we found high genetic diversity at microsatellite loci, suggesting that these populations likely have heterogeneous origins rather than being introduced from a single source population. However, within individual populations, genetic diversity was low, consistent with each population being started by a small number of individuals, even a single inseminated female. Microscale studies of aggregations within apartments in a single, multi-unit building indicate that the building was likely infested through a single introduction of an inseminated female which founded a population that subsequently expanded and spread to more than 20 apartments. Finally, we found high prevalence of one or both of two mutations for insecticide resistance in 38 populations in the U.S. Together our results provide important insights into the modes of dispersal, levels of genetic diversity and information on the frequency of insecticide resistance in U.S. populations of bed bugs.