Materials for Control of Boll Weevils, Bollworms, and Tobacco Budworms on Cotton at Stoneville, Mississippi1234

Abstract

When experimental insecticides were evaluated for control of boll weevils, Anthonomus grandis Boheman; bollworms, Heliothis zea (Boddie); and tobacco budworms, H. virescens (F.), on cotton in field-plot tests at Stoneville, Miss. in 1969, CIBA C-9491 ( O -(2,5-dichloro-4-iodophenyl) O,O -dimethyl phosphorothioate) and Velsicol VCS-506 ( O -(4-bromo-2,5-dichlorophenyl) O -methyl phenylphosphonothioate) applied as conventional emulsifiable concentrate sprays gave control of Hetiothis spp., primarily tobacco budworms, comparable to the standard treatment. Several other materials including formulations of Bacillus thutringiensis Berliner were less effective. Ultra low volume (½ gal or less/acre) sprays of EPN ( O -ethyl O-p -nitrophenyl phenylphosphonothioate), EPN + methyl parathion, malathion + methyl parathion, methyl parathion, and toxaphene + DDT + methyl parathion gave very good control of Hetiolhis . Control of the Heliothis resulted in increases in yield of as much as a bale of seed cotton/acre.