Activity of insecticides applied to turfgrass to control adult cat fleas (Siphonaptera:Pulicidae)

A bioassay was developed to determine the efficacy of insecticides against adult cat fleas, Ctenocephalides felis (Bouché), on turfgrass. Activity was assessed by exposing adult fleas to treated and untreated disks of turf for 24 h, 1 and 7 d after treatment. Filter paper, a representative nonwaxy, porous substrate was bioassayed in similar fashion 1 d after treatment to confirm insecticide activity. Results demonstrated the relative efficacy of insecticides applied to turf at different rates as well as differences among insecticides. Of 10 insecticides tested, chlorpyrifos wettable powder and emulsifiable concentrates consistently provided greatest kill of adult fleas. Although initially active, pyrethroid insecticides and diazinon generally showed significant declines in residual activity by day 7. Possible reasons for differences in activity are discussed.