Technical Abstract: Extracts of glandular trichomes from Medicago sativa were tested for their ability to disrupt the settling behavior of the potato leafhopper, Empoasca fabae. Erect and procumbent glandular trichomes were mechanically isolated from stem sections of the resistant genotype 'G98A', and nonglandular trichomes were collected from the susceptible cultivar 'Ranger'. Isolated trichomes were extracted with chloroform, acetone, and ethanol, and the resulting crude extracts were applied to the surface of a sachet containing an artificial diet. Leafhoppers were then offered a two-way choice between crude trichome extracts from G98A and Ranger. All three of the G98A solvent extracts caused various degrees of diet rejection, resulting in the crude Ranger trichome extracts being preferred over the G98A extracts. Overall, the fewest leafhoppers settled on the ethanolic extracts. Additional bioassays documented a dose response associated with the G98A ethanolic extracts when compared against the Ranger trichome extracts and also a solvent control. No difference in preference behavior was detected between the Ranger trichome extracts and a solvent control. GC-MS analysis revealed a homologous series of nonvolatile fatty acid amides CnH2n+1NO (n = 19-23) unique to the G98A glandular trichome extracts.