Differential populations of cotton aphids (Aphis gossypii) and silverleaf whitefly (Bemisia argentifolii) were established in neighboring plots of pima and acala cotton. Studies were conducted in the California San Joaquin Valley. Naturally-occurring late-season populations were manipulated with insecticides such that lint in some plots was exposed to levels as high as 50 aphids per leaf whereas other plots were devoid of these late-season insects. Lint stickiness was determined at harvest as well as the progression of stickiness was monitored from the start of boll opening until harvest.