METHOD: Feeding Behavior CONDITIONS: Green House - 16h light at 27C and 50% RH METHOD NARR: Excised leaflets were arranged in a preference arena, and CPB were allowed to orient freely for the choice preference test. Leaflets ofssed to both surfaces of tuberosum leaflets to determine if resistance was localized in trichomes. Trichomes were also removed to see what effect that would have on choice. The trichome removal experiments were repeated us preference data were recorded after 24 hrs. RESULTS NARR: Adults and larvae preferred tbr in choice tests. Given a choice of the two ber accessions, feeding was reduced and no preference was detected in adults. Choice betwresulted in a decrease in the initiation of feeding and no preference. When ber leaflets were appressed to tbr leaflets, the non-appressed control tbr were preferred. Choice between trichome 'intact' or 'removed' resulted in preferen trichomes removed, and the preference increased as degree of removal was increased. Complete removal of trichome resulted in feeding levels close to tbr. AUTHOR EXPLANATION: The increase in adult feeding with trichomedegree of trichome removal. This work supports the hyothesis that type A trichomes are required for expression of resistance, while type B sugar esters may enhance the effect. The expression of resistance is dependePB.