Loss of insecticide susceptibility was suspected in lesser mealworms, Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae), in broiler chicken facilities in Arkansas due to reports of control failures. Bioassay tests using selected insecticides were conducted on adult and larval beetles collected from broiler chicken production farms having different insecticide application history. The residual and topical application tests showed that previous insecticide use had caused significant differences in the relative susceptibility of lesser mealworms. Topical application bioassay tests indicated that adult beetles had greater susceptibility to the insecticides tested than 8^th instars collected from the same farm while in residual tests little difference was generally found in the susceptibility of adults and larvae exposed to the insecticides. Data suggested that the ability to de-toxify DDT and other organochlorine insecticides remained in some beetle populations due to spread of wood-shaving litter containing beetles over pastures among broiler production facilities, particularly involving facilities that have been in broiler production for over 40 y. A program utilizing integrated tactics that will reduce the dependency on insecticides is needed to manage litter beetles in poultry production facilities.