Seasonal field increases in the number of boll weevils in Dickens and Kent Counties of Texas were found to fit logistic growth curves. Boll weevil numbers increased exponentially through July, Aug., and Sept. at rates up to ca. 2.70-fold/wk in an untreated field compared to 1.74-fold avg in insecticide treated fields. During Oct. the population growth rate slowed and finally reached zero.The relation between the mean number of squares available to each weevil and percentage of weevil damaged squares fit a curvilinear model. This model can be used to provide an estimate of the number of adult weevils per ha based on % damaged squares and an estimate of the number of squares per ha. Conversely, numbers of damaged squares can be estimated based on numbers of adult weevils.