A study was conducted in Imperial Valley, CA, in 2005, to evaluate insecticides for control of silverleaf whitefly, Bemisia argentifolii, Bellows and Perring, in cotton. Several insecticides were compared for efficacy against silverleaf whitefly adults, eggs and nymphs including a newly registered insecticide, Oberon (spiromesifen) a product of Bayer CropScience, Leverage (imidacloprid and cyfluthrin) a neonicotinoid insecticide and pyrethroid insecticide in the can mixture a product of Bayer CropScience, Assail (acetamiprid) a Cerexagri, Inc. neonicotinoid insecticide, Actara (thiamethoxam) a Syngenta Crop Protection, Inc. neonicotinoid insecticide, Capture (bifenthrin) a pyrethroid insecticide of FMC Agricultural Products, and a combination of Danitol (fenpropathrin) plus Orthene (acephate) Valent USA Corporation's pyrethroid insecticide and organophosphate insecticide, respectively. The whitefly adult, egg and nymphal post-treatment means for all insecticide treatments were lower than the untreated control means on most sampling dates, but Assail and Oberon post-treatments were consistently lower than the untreated control and lower than the means for other insecticide treatments. The seasonal means for whitefly adults, eggs and nymphs for insecticide treatment were all lower than the untreated control seasonal mean, but Assail and Oberon seasonal means were the lowest among the insecticide treatments.