The role of pre- and post-imaginal experience in the host-finding and oviposition behaviour of the cabbage moth

The influence of pre- and post-imaginal experience on the orientation, land ing, and oviposition of the female cabbage moth, Mamestra brassicae (L.) (L epidoptera: Noctuidae) was studied in a wind tunnel. The results of experim ents on the influence of pre-imaginal experience do not support the Hopkins host selection hypothesis because the females' responses to host plants we re not affected by the plant species used for feeding the larvae. The femal es were initially attracted to and landed on chrysanthemum whether or not t hey were fed on this plant species. In addition, the oviposition preference for cabbage plants was not changed by the larval feeding regimen. Imaginal experience influenced the females' subsequent orientation/landing response s: exposure of the females to chrysanthemum plants for 5 min decreased thei r subsequent responses to this species, but subsequent responses to cabbage were not changed when the females were exposed to cabbage plants. Overnigh t exposure of females to chrysanthemum or cabbage plant decreased the subse quent orientation/landing on the same species offered in non-choice tests. A similar effect was observed in responses to chrysanthemum plants after ov ernight contact, and possibly to cabbage plants, in the two-choice tests. O vernight exposure to cabbage or chrysanthemum had no effect on subsequent o viposition: females from both treatments oviposited more often on cabbage.