Bionomics of Diamond-back Month, Plutella xylostella(Lepidoptera: Plutellidae) in Southern Region of Korea

남부지방에서 배추좀나방의 발생생태에 관한연구

These studies were conducted to investigate overwintering forms and adult population fluctuation in field condition, and life cycle in field-cage condition of diamondback moth, Plutella xylostella (L.). Plutella xylostella overwintered as all the stages of eggs, larvae, pupae and adults in southern region of Korea. The occurrence which adult moths were attracted by light trap at 5-day intervals, reached their peaks in May, mid-June to mid-July, and late September to early November, and fell in late July to mid-September. Under field-cage condition, they occurred 10-11 generations a year and the period of adult emergence from egg was 11-18 days in July and August, 19-23 days in June and September, 28-34 days in April, May and October, and about 50-100 days in other months. And the longevities of adults were 4-11 days in summer, 7-17 days in spring and fall. A number of eggs laid by individual female ranged from 50 to 240. The females laid more eggs in spring and fall than they did in summer. The period of developmental stages under field-cage conditions was 2-3 days for eggs, 7-8 days for larvae and 4-6 days for pupae in July and August; 4-5 days for eggs, 3-12 days for larvae and 6-8 days for pupae in June and September; 6-18 days for eggs, 13-20 days for larvae and 8-14 days for pupae in March, April, May and October; and 12-40 days for eggs, 50-100 days for larvae, and about 20 days for pupae in winter.

남부지방에서 배추좀나방은 각 태 모두 월동 가능하였다. 유아등에 의한 성충발생소장을 보면 5월, 6월 중순~7월 중순, 9월 하순~11월 상순에 발생량이 많았고, 7월 하순~9월 중순에는 적었다. Field-cage 조건하에서 연 발생세대수는 10~11이었고, 란에서 유화까지 7, 8월에는 11~18일, 6, 9월에는 19~23일, 4, 5, 10월에는 28~34일이었으며, 기타 기간에는 50~100여일 경과하였다. 성충수명은 여름에 4~11일, 봄 가을에는 7~17일이었고, 산란수는 50~240개로 봄 가을에 많으며 여름에는 적었다. Field-cage조건하에서 각 태별 기간은 7, 8월에 난이 2~3일, 유충은 7~8일, 용은 4~6일이며, 6, 9월에는 난이 4~5일, 유충은 9~12일, 용은 6~8일이고, 3, 4, 5, 10월에는 난이 6~18일, 유충이 13~20일, 용이 8~14일이며, 겨울동안은 난이 12~40일, 유충이 50~100일, 용은 20일정도 경과하였다.