This paper discusses spatial analysis of sterile and native pink bollworm (Pectinophora gossypiella (Saunders)) populations in the Imperial Valley of California. Native and sterile moths were monitored season-long with traps checked once per week and numbers of moths recorded. Trap locations and the geographic boundary of each field was recorded. Release of sterile moths began early in an effort to have high numbers of sterile moths in the field before native populations could develop. In the last two years, following the development of genetically modified cotton, early to mid-season releases were directed toward the conventional cotton refugia. Native moth populations typically increase dramatically in late season at which point sterile release is shifted away from refugia and onto the genetically modified cotton fields as a hedge against resistance. Sterile moths act as pseudo-refugia since mating of native and sterile moths produce no offspring, resistant or otherwise. We are investigating the role of sterile insects and the dispersal of refugia as resistance management tactics.