Abamectin 0.15 EC Miticide/Insecticide has been evaluated for spider mite control on cotton in the San Joaquin Valley for several years and is in the final development stage prior to receiving official EPA registration. Results show that abamectin provides excellent control of all three species of spider mites common to the San Joaquin Valley (Tetranychus urticae, T. turkestani, and T. pacificus). Abamectin has been tested on the major varieties of cotton grown in the San Joaquin Valley at recommended, and in some instances, exaggerated use rates and frequencies of application with no evidence of phytotoxicity. Results from 1987 and 1988 testing under an EUP with temporary tolerance in replicated commercial ground trials confirm earlier research work. The data show that abamectin provides good reduction of initial spider mite populations and superior residual spider mite control compared to the commercial standards, dicofol and propargite.