METHOD: Chemical Assay CONDITIONS: Green House - 16h light at 18-27C and rh between 60-90% METHOD NARR: Trichome exudates were collected from type A and B trichomes. Whole-leaf sesquiterpenes were collected and purified. ID of determined using GC-MS. The influence of extracted sesquiterpene fractions on settling behavior of M. persicae was determined using a test arena. Numbers of aphids present on each of the feeding areas were determined afterB-caryophyllene and D-Cadinene were to major components identified in type A trichomes. Two minor components were a- Copaene and E-B-Farnesene. Concentrations of sesquiterpenes (SQT) from type B trichome exudate varied conside 0.34% had a repellent effect on aphids. At 0.25% the SQTs failed to discourage settling. AUTHOR EXPLANATION: There were qualitative and quantitative differences in sesquiterpenes (SQT) from sib-mated plants, suggesting a genetic brences. Results indicate that SQTs other than E-B-farnesene alter aphid behavior. Authors hypothesize that the SQTs are not produced by type B trichome glandular cell. Rather they are readily taken up from the environmeichome tip and slowly released again.