Deltamethrin to control the boll weevil

Abstract

The effect of the EC, FLOW and ULV formulation of deltamethrin and cypermethrin ED on the cotton boll weevil Anthonomus grandis Boheman, 1843 (Coleoptera: Curculionidae) at Campina Grande, PB, Brazil, was studied. The randomized complete block design with four replications and eight treatments as folows was used: Deltamethrin (Decis FLOW 50 SC) 10 and 12,5 g a.i./ha; (Decis ULV) 7,5; 10,0 and 12,5 g a.i./ha; (Decis EC) 12,5 g a.i./ha; Cypermethrin (Cymbush 30 ED white nozzle) 8,34 g a.i./ha and check. All the treatments were efficient to maintain the square infestation around the action level, which is 10% of infested squares, up to eight days after the third application. High weevil density may be reduced by three insecticide applications at a three-day interval.