SummaryFour introductions of Sohmum berthaultii wild species and seven S. tuberosumxS, berthaultii hybrids were evaluated by antibiosis and antixenosis laboratory tests with potato tuber moth. Some morphological and chemical traits related to the trichomes were analysed. Two clones of the wild species S. spalwipilum and five of S. pinnatisectum, characterised by high tuber resistance, were tested for leaf resistance, both by antibiosis and antixenosis assays. The genotypes with high density of trichomes A and with high cxudate PPO activity, showed a moderate negative effect on pupal weight and fecundity in the antibiosis tests. Trichomes B exudate showed a strong repulsive effect on oviposition of adult in the antixenosis tests. The S. pittnatisectttm clones revealed a good leaf resistance level, whereas the S. sparsipihtm clones showed lower levels of antibiosis and antixenosis.