Evaluation of the Juvenoid Fenoxycarb Against the German Cockroach, 1986 & 1987

Two separate 9-mo control programs were conducted to determine the relative efficacy and residual life of the juvenoid fenoxycarb (25.2% emusifiable concentrate) applied in a tank mix with residual neurotoxic insecticides. In each study, the residual insecticide was applied alone and served as a positive control. Multifamily public housing units served as the test sites; individual apartments served as the replicated experimental unit. Test sites for Test 1 were located in Hammond and Elkhart, Ind.; those for Test 2 were located only in Elkhart. Test 1 compared the cockroach control from applications of Dursban LO (0.5%) with the control from applications of Dursban LO (0.5%) plus fenoxycarb (0.25%) and was initiated in October 1985. In this test, the treatments were re-applied following the 1- and 6-mo evaluation periods. Test 2 compared the cockroach control from applications of Safrotin EC (1.0%) with the control from Safrotin EC (1.0%) plus fenoxycarb (0.125%) and was initiated in March 1986. In this test, the treatments were re-applied following the 2- and 6-mo evaluation periods. Sprays were applied using 1-gal B&G compressed-air sprayers equipped with Multee-jet nozzles. Due to high cockroach populations and poor sanitation, a general clean-out procedure was followed. All accessible harborage areas throughout the apartment were treated, and approximately 0.5 gal of spray was used per unit. The exact volume applied varied due to apartment size and the amount of harborage to treat. The performance of the spray program was monitored for 9 mo following the initial applications, with retreatments occurring as previously noted. Population levels were estimated by visual counts throughout the kitchen and bathroom areas, and a minimum precount of 20 cockroaches was required for any apartment to be considered as a test. Each treatment was replicated in 12-15 apartments, but the sample size for posttreatment counts varied due to apartment vacancy or the lack of resident cooperation. To determine insecticidal efficacy, posttreatment visual counts were reduced to percent reductions of the pretreatment cockroach counts. Additionally, sticky traps (Raid Roach Traps) were placed in the apartments overnight at each sampling to monitor the frequency of morphogenetically deformed adults exhibiting the juvenoid induced twisting of wings, which is correlated with sterility.