METHOD: Test Diet CONDITIONS: Lab METHOD NARR: Ber 473340 has two clones named 1726 and 1729 which differ in the type of trichome found on leaves. Types A & B on 1726 while 1729 bears only type A. A no-choice bio-assay was condas well as tbr leaves treated with ber extracts. Consumption was measured by area. Overwintered and first generation adults were also tested. RESULTS NARR: The overwintered beetles consumed ~ half the amt of foliage of fConsumption of tbr treated with ber1726 extract decreased linearly as the extract concentration was increased. The presence of type B exudate on tbr reduced cunsumption of first generation beetles. AUTHOR EXPLANATION: The drp of a long hair, constitute a barrier of concentrated feeding deterent and may be more effective than the extract spread on the surface of the leaf. Results support the conclusion that the trichome B exudate is the active fraction ofract and that the resistance of clone 1729 is based on a different mechanism.