稻纵卷叶螟自然种群生命表的研究及其在测报上的应用

STUDIES ON THE NATURAL POPULATION LIFE TABLE OF RICE LEAF ROLLER AND ITS USE IN PREDICTION

1981—1987年,研究了稻纵卷叶螟的自然种群生命表。经回归系数b值法(Podler等,1975)分析表明,一至二龄和三龄幼虫期是影响种群数量变动的关键时期,捕食性天敌及气候因子所导致的害虫失踪是数量变动的关键因子。并根据生命表资料和对关键因素建立亚模型的方法,组建了自第三代迁入蛾量起预测当代三龄幼虫数量的预测式。本模型在郑州地区应用准确率达80％以上,有效地指导了防治。

In 1981—1987,the natural population life table of rice leafrollerCnaphalocrocis medinalis(Guenée)were studied in paddy fields,inZhengzhou,Henan Province.The results of b value analysis(Podler &Rogers,1975)showed that the main population fluctuating stages werein lst—2nd instar and 3rd instar of larva,and the key factors contri-buting to mortality of the two larva stages were predators and adverseweather condition.A prediction model for the 3rd instar larva densityof the 3rd generation relying on the immigrated moth number and so onof this generation was established.The accuracy rate of forecast asused in Zhengzhou region was more than 80%,it is quite available forthe control of this insect.