越冬代棉大卷叶螟的种群动态

对棉大卷叶螟Sylepta derogata Fabricius第5代、第6代室内种群饲养结果显示,该虫的有效越冬虫源为第5代滞育的老熟幼虫,滞育率24.4%～33.1%,第6代棉大卷叶螟的发生对第2年的种群基数影响不大。滞育老熟幼虫的越冬存活率为60.0%～71.9%。次年越冬代羽化的成虫雌虫少,雄虫多,单雌产卵量平均为163.4～198.8粒。

Population dynamics of the overwintering generation of Sylepta derogata

By rearing the fifth and sixth generation of Sylepta derogata Fabricius with two cotton cultivars Simian-3 and Sumian-12 in laboratory,it was found that the effective overwintering insect into next year came mainly from the fifth generation of S.derogata,with the diapause rate 24.4%～33.1%.The occurrence of sixth generation of S.derogata had little effect on the population size in the next year.The survival rate of diapaused larvae was 60.0%～71.9%.In the next year,the number of females coming from overwintering larvae was less than that of males,and the everage number of eggs per female was 163.4～198.8.