The author previously mentioned that there might be a causal relation between the quantities of cultivation of the host plants and the tendencies of food preference of the common cabbage butterfly larvae. To ascertain this relation, the present experiment was planned. The common cabbage butterflies were reared successively for ten generations with cabbage for food. Tendencies of food preference of the fifth instar larvae (LC) between the cabbage and radish leaves were examined at the second, fifth and ninth generations. Also the larvae which were reared by radish (LR) for only one generation following the culture of one or five generations on cabbage, were examined similarly. The results are : 1. The larvae (LC) at the second or fifth generation cultured on cabbage showed no clear preference between the cabbage and radish leaves. This behavior bore some resemblances to that shown by the larvae collected directly from field at Sasayama. The larvae at the ninth generation preferred decidedly the cabbage leaves, which seemed to indicate that the change in the tendency of food preference had been established (Tables 1,2,3). 2. When the larvae, whose parents had been reared by cabbage, were cultured by radish, they preferred the radish leaves. Whereas when the larvae, whose ancestors had been reared by cabbage for five generations, were cultured by radish, they showed no clear preference between cabbage and radish leaves (Tables 4,5). 3. Therefore, a conclusion may be suggested that the larvae reared by a specific host plant successively for a certain generation will prefer that host plant.
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