The development of cotton aphid resistance to insecticides has brought about a need for a better understanding of the roles played by biological control agents in the cotton agroecosystem. The objectives of this research were to evaluate the interactions of pesticides and natural enemies in suppressing aphid populations. Four treatments were evaluated during the course of this study: (1) weekly application of Provado; (2) weekly application of Bravo; (3) application of Provado when aphid thresholds are exceeded; (4) untreated control. Weekly Provado treatments significantly reduced cotton aphid populations in 1996 and 1997. The entomopathogenic fungus, Neozygites fresenii, appeared to greatly reduce aphid population levels during both years as well. No significant differences in yield were observed for either year.