Two feeding periods of adult cabbage seedpod weevils (Ceuto-rhynchus assimilis) involve different habits. Prehibernation feeding activities are largely on chlorophyll-bearing tissues, usually thickened parts of plants such as stems, leaf veins, or pods. This feeding seems to be confined to the genera Brassica and Raphanus (Cruciferae). Post-hibernation feeding is mostly on nectar of flowers, largely in the genera Brassica and Raphanus, but occasionally on flowers of other crucifers. Larval feeding is on developing seeds within pods, and has been observed only in members of the genera Brassica and Raphanus. B. hirta (white mustard) and B. nitra (black mustard) are apparently immune to larval attack, and B. kaber (charlock) is subject to only very limited attack. B. juncea (Indian mustard) and B. campestris (wild turnip or common yellow mustard) are subject to moderately severe attack. Larval populations in radish pods are not as great as in the Brassicas, but seed damage is considerable. There is considerable variation in the susceptibility of the several garden types of Brassicas to weevil attack, but all are subject to serious damage: Chinese cabbage and Shogoin turnip appear to be the preferred hosts. Cabbage ranks quite high, with considerable variation in vars. Turnip (except Shogoin) and rutabaga seem less susceptible than cabbage, and kale lower than these.