THE EFFECTS OF WILD CRUCIFEROUS HOST PLANTS ON MORPHOLOGY, REPRODUCTIVE-PERFORMANCE AND FLIGHT ACTIVITY IN THE DIAMONDBACK MOTH, PLUTELLA-XYLOSTELLA (LEPIDOPTERA, YPONOMEUTIDAE)

The wild crucifers, Rorippa indica and Lepidium virginicum, are known to serve as host plants for the diamondback moth (DBM), Plutella xylos tella, but they are less suitable than the preferred cultivated crucif erous plant, cabbage, in terms of adult body size and fecundity. The l ife history traits and flight activity of DBM adults grown on various host plants were investigated. The adults thus reared on each host pla nt were divided into three size groups (small, medium and large). In g eneral, female adults grown on the wild crucifers were less fecund and lived longer than those reared on cabbage. Flight activity was higher in adults grown on wild crucifers than in those reared on cabbage. Ma le adults flew longer than females. Fecundity, longevity, flight activ ity and morphometrical characters of adults were positively correlated with pupal weight in individuals reared on the same host plant. A neg ative relationship was found between fecundity and flight activity in females of the same size group, but a positive one was observed in fem ales reared on the same host plant.