New Insecticides for Boll Weevil, Bollworm and Aphid Control

Abstract

Benzene hexachloride mixtures applied at the rate of 11-12 lb. per acre, containing as low as 2.88% y isomer, proved to be as effective against the weevil as Ca arsenate in one expt., while in other expts. this percentage of y isomer was less effective. The mixtures applied at 11-12 lb. per acre containing at least 5% y isomer were equal to or, in one expt., significantly more effective against weevils than Ca arsenate. Apparently a minimum dosage of 8 ounces of y isomer per acre was necessary to give adequate control of severe weevil infestations. Benzene hexachloride, in all concs. used, prevented aphid increases but produced increased bollworm injury. 5% DDT dust mixtures were effective against the bollworm but ineffective against weevils and caused aphid increases. Populations of red spiders were noted on both DDT and benzene hexachloride treated plats when sulfur was not used as a diluent. The mixture of DDT and benzene hexachloride was effective against weevils, bollworms and aphids, but did not significantly increase the yields over Ca arsenate.