Development and survivorship of the cotton aphid, Aphis gossypii Glover, on selected cotton race stocks

Forty-five cotton race stocks and diploid wild cottons obtained from the National Collection of Gossypium Race Stock in College Station, Texas, were screened for antibiotic cotton aphid host plant resistance. Aphids were caged on each of the race stocks and the first progeny was followed through development to adulthood. Cottons were rated using observed survivorship and developmental times of test aphids. Data were converted to percentage mortality and percentage of developmental duration as compared to the susceptible control cotton using Abbot's formula, then a multiple resistance statistic (MRS) was computed by averaging the two. Race stock TX004 had the best performance of the cottons tested, with zero aphids surviving to adulthood. Based on the MRS, six other cottons (TX003, TX008, TX188, TX009, TX034, and A1-072) showed excellent potential for developing cotton aphid resistant cotton cultivars. The results of this study need to be repeated for validation, and continued testing of obsolete race stocks and wild cottons is recommended.