Laboratory and Field Trials of Permethrin-Treated Cotton Used as Nesting Material to Control Fleas (Insecta: Siphonaptera) on Cricetid Rodents

Upholstery cotton treated with four different concentrations (0.25–2.0%) (2,500–20,000 ppm) of an aqueous permethrin solution, used as nesting material by white mice, was laboratory-tested against the potential plague vectors Oropsylla montana (Baker), Thrassis bacchi (Rothschild), and Orchopeas howardi (Baker) and found highly effective ( P 4 mo when tested during winter in Larimer County, Colo. Permethrin-treated cotton was less successful in controlling fleas on cricetid rodents during the summer months in a New Mexico hyperendemic plague area.