Field Trials of Insecticidal Sprays, 1991

Abstract

Abstract Field tests determined the relative efficacy and residual life of six spray treatments: 0.1% Tempo EC (TEC); 0.1% Tempo EW (TEW); 0.2% permethrin, 0.2% pyrethrins, and 0.5% piperonyl butoxide (PPPB); 0.1% cyfluthrin, 0.05% pyrethrins, 1.0% Baygon, 1.0% piperonyl butoxide (CPBPB); 1.0% Baygon (B); and 0.1% pyrethrins, 0.4% tetramethrin, and 0.15% cypermethrin (PTC). The Dorie Miller Homes, Dorie Miller Homes East, Ivanhoe Gardens, Duneland Village, and Concord Village, multi-family public housing complexes located in Gary, Indiana, served as the test sites; individual apartments served as the replicated experimental unit. PPPB, CPBPB, B, and PTC treatments were made with self-pressurized aerosol cans containing formulated active ingredients. The other treatments were applied using 3.8 liter compressed air sprayers equipped with Multee-jet nozzles. Due to the high cockroach populations and poor sanitation, a general “clean-out” procedure was followed. All accessible harborages throughout the apartment were treated. After 4 wk, all apartments received a second treatment. Population levels were estimated by visual counts throughout the kitchen and bathroom areas, and a minimum pretreatment count of 20 cockroaches was required for any apartment to be considered as a test. Each treatment was replicated in 10-15 apartments, but posttreatment counts varied due to apartment vacancy or lack of resident cooperation. To determine insecticidal efficacy, posttreatment visual counts were reduced to percentage of reductions of the pretreatment counts. Some counts were terminated after 10 wks. Prior to statistical analysis, percentage of reduction data were transformed to ranks. These were analyzed with ANOVA models, followed by the Fisher’s protected least significant difference (P = 0.05) to determine significance among the treatments at each posttreatment census.