Methoprene Dust for Flea (Siphonaptera: Ceratophyllidae) Suppression on Ground Squirrels (Rodentia: Sciuridae)

摘要

Mexican ground squirrel, Spermophilus mexicanus parvidens Mearns (Rodentia, Sciuridae), burrows on Brooks AFB, Texas, were dusted with methoprene at the rate of 0.05g active ingredient per burrow. Early spring posthibernation and fall prehibernation dusting were evaluated for their efficacy in reducing populations of Thrassis foetus (Jordan) (Siphonoptera; Ceratophyllidae), the only flea species found on the ground squirrels. The early spring treatment was found ineffective while the fall application significantly reduced flea populations the following spring. Bionomic information on T. foetus gained during this study included the finding that this flea is a cool wheather species with its most significant reproductive period in the cool south Texas winter months. Adult fleas completely disappeared from squirrels from mid-June until late fall. Additionally, male ground squirrels were more heavily infested with fleas than were females. Methoprene may be a promising adjunct to currently used insecticides for wild rodent flea control.