印度谷螟的季节消长及其防治

A STUDY OF THE POPULATION DENSITY FLUCTUATION OF INDIAN MEAT MOTH AND OF ITS CONTROL

印度谷螟是四川为害贮粮和食品的重要害虫。本文研究了该虫在核桃干果中的季节消长、影响因素及其防治.结果表明,印度谷螟在重庆室温条件下,全年发生四代,7～9月的二、三代种群数量较大。越冬幼虫在10℃以下经90天左右50%个体死亡,16℃以上发育成蛹或羽化.成虫交配率和繁殖力在26～30℃时较高.取食葡萄干和核桃仁有利该虫的生长发育.麦蛾茧蜂春季寄生率约为14%,夏秋季为9～25%。一个寄主幼虫出2～7头寄生蜂幼虫.

An investigation was made of the fluctuation pattern of the population density of In-dian meat moth,an important pest infesting stored products in Sichuan,and the factorsthat influence its development in the four years from 1988 to 1991.Four generations werwfound to occur in a year,feeding on walnut kernels at room tempertures.Great populationdensity of the 2nd and 3rd generations were observed during the period from July to Sep-tember.When the larvae in hibernation were subjected to a temperatureof 10℃ or lowerfor 90days or so,about 50% of them died.At temperatures higher than 16℃ ,theoverwintered larvae might develop into pupae or adults.The moths showed highest matingcapacity and fedundity at 26—30℃.The survival rate and reproduction capacity of the in-dividuals feediog on raisins and walnut kernels appeared to be higher.A parasite,Braconhebetor,was found to attack the larvae of the Indian meat moth,the parasitised percentagebeing ca.14% in spring and 9—25% in summer and autumn.A dead host's body mightsend out 2-7 parasite larvae.Possible control methods for the pest are discussed.