Insecticides for Cat Flea Larvae Control, 1980

The performance of residual deposits of insecticides applied to carpet was evaluated against 2nd to 3rd instar cat flea larvae. Larvae were obtained from eggs from adult fleas maintained on caged domestic cats. Larvae were provided rearing medium consisting of pulverized dog chow, dried beef blood and brewer’s yeast (20:3:2 by wt). When 7 days old, larvae were aspirated from a thin layer of their media scattered in a porcelain pan. A very common short shag carpet 5/8-inch deep was treated. The carpet had 196 double mulfifiber strands of 100% nylon/sq inch. Discs of carpet (3.5 in diam) were treated with the liquid insecticides sprayed from a custom-made paint gun sprayer equipped with a fine-fan nozzle. The Spray was delivered at 20 psi. Replicated series of discs were sprayed to provide 23.7 mg ai/sq ft when 0.5% concentration was used. Higher and lower concentrations provided proportionately more or less active ingredient. A predetermined amount of aerosol was applied from ca 6-8 in to provide comparable rates of active ingredient with insecticides applied with the sprayer. Sprays of Ficam W and Knox Out were also applied at 20 psi from a 1-gal B&G compression sprayer equipped with a Spraying Systems Multeejet no. 800067 fine-fan nozzle. Sprays were applied at 1-gal/800 sq ft. Three plugs (0.8-in diam) cut from treated and untreated carpet were placed at the bottom of individual 0.8-inch diam x 3-inch glass shell vials. Larval medium (ca 0.1 cc) was tapped to the base of each plug. Ten larvae placed on each plug were maintained for at least 5 days in a desiccator chamber at 80°F, 75% RH. After exposure, each replicate was examined for adults, pupae and larvae. About 95% of larvae in the untreated series could be accounted for, mortality ranging from 0 to 10%. Larval mortality on treated carpet was corrected with Abbott’s formula.