Control of Certain Cotton Pests with a New Systemic Insecticide, UC-211491

Abstract

An experimental systemic insecticide, Union Carbide UC-21149 (2-methyl-2- (methylthio) propionaldehyde O- (mcthylcarbamoyl) oxime), was compared with Di-Syston® ( 0,0 -dicthyl 5-[2- (ethylthio) ethyl] phosphorodithioate), and phorate in granular formulations applied at planting as in-furrow treatments for control of early-season cotton insects. Additional tests were conducted with UC-21149 as seed treatment or sidedress applied at various stages of cotton plant growth for control of the boll weevil, Anthonomus grandis Boheman. In the in-furrow treatments at planting, Di-Syston and phoratc adversely affected stands of cotton; but UC-21149 did not. UC-21149 was as effective as Di-Syston and phorate against a thrips complex [flower thrips, Frankliniella tritici (Fitch) ; F. exiguia Hood; tobacco thrips, F. fusca (Hinds); and grain thrips, Limothrips cerelium (Haliday)]; the cotton aphid, Aphis gossypii Glover; and an artificially induced infestation of the carmine spider mite, Tetranychus cinnabarinus (Boisduval). Mortality of overwintered boll weevils was significantly greater with UC-21149 and phorate than with Di-Syston. UC-21149 applied as a seed treatment reduced stands and was ineffective against the cotton aphid. Sidedress treatments produced significant mortality of boll weevil larvae developing within the squares and bolls, and of adults feeding on terminal growth. It also controlled the cotton aphid and carmine spider mite. However, UC-21149 was ineffective against the bollworm, Heliothis zea (Boddie), and cabbage looper, Trichoplusia ni (Hubner). Bollworms increased in 1 test, apparently owing to a lack of beneficial insects. Phytotoxicity was observed at the high rates shortly after treatment, but it did not appear to persist on subsequent plant growth.