Cotton aphids, Aphis gossypii Glover, were collected for 3 yr from cotton fields in Alabama and Texas, and screened for resistance to four pyre throed and eight oregano phosphate insecticides. Resistance ratios were based on Comparisons of the LC50s of field populations with the LC50s of a susceptible laboratory population. During 1988, resistance to the pyrethroids bifenthrin and cypermethrin was low (