ABSTRACT

Three neonicitinoid insecticides (acetamiprid, thiamethoxam, and imidacloprid) and one organophosphate insecticide (dicrotophos) were evaluated for control of the cotton aphid (Aphis gossypii Glover). In addition, the effects of these chemistries on populations of predators, pests and eggs of Helicoverpa zea were monitored during the 2002 and 2003 seasons in both conventional and B.t. cotton. Acetamiprid and thiamethoxam provided adequate control of A. gossypii, whereas dicrotophos, at times, flared populations. Imidacloprid was less effective in controlling A. gossypii than either acetamiprid or thiamethoxam. Dicrotophos controlled stink bugs and cotton fleahoppers but had an adverse impact on predators which resulted in higher populations of lepidopterous pests later in the season. Acetamiprid and thiamethoxam demonstrated ovicidal activity against H. zea. The neonicotinoids exhibited varying activity against sucking pests, predaceous arthropods, and later-developing populations of lepidopterous pests.