HIBERNATION AND FLIGHT ABILITY OF THE CABBAGE WEBWORM, HELLULA-UNDALIS IN JAPAN

The hibernation ecology and flight behavior of the cabbage webworm, He llula undalis were studied from 1983 to 1987 in the field and by labor atory experiments. Overwintering of H. undalis was estimated to be suc cessful in the southern parts of the Kanto district along the Pacific Ocean and of the Hokuriku district along the Sea of Japan; this specie s was able to hibernate in the last instar larval or pupal stages. H. undalis could not overwinter under adverse field conditions when expos ed to a temperature below 0-degree-C for more than 10 days during the winter. The flight ability was determined using a flight mill; the pot ential flight distance was 40 km for female and 50 km for male adult m oths. However, on the basis of studies on the relationship between the flight behavior and reproductive success of females, and on the fligh t behavior in mark-recapture experiments with males, it was concluded that the flight characteristics of H. undalis were not adequate for lo ng-distance overseas migration.