Previous research indicated six of 116 cotton race stocks as showing some resistance to sucking insects, specifically whitefly (Bemisia tabaci), using an excised leaf technique as described by Ripple. Current research focusing on these six race stocks indicates intrastock variation in resistance to whitefly is present. Our goal is to identify the best individual plants from the most promising race stocks by evaluating resistance to whitefly in whole plants. The best individual plants identified within each race stock will be used to make individual plant selections for further breeding and extension of work from the laboratory into the field.