论文部分内容阅读
美国白蛾传入我省后主要靠化学药剂防治,对于发生时间集中,虫口密度大的害虫收到了一定的防治效果。但对于那些发生量小,虫口密度不大,幼虫还没有扩散的地区,靠人工摘除网幕也能收到良好的防治效果。美国白蛾幼虫四龄前多聚居在网幕内,集体觅食,四龄以后才出网分散觅食。第一代幼虫一般在树的中下部枝梢上结网;第二代幼虫一般在树的中
After the American white moths were introduced into our province, they were mainly controlled by chemical agents. For those pests that concentrated in time and had a high density of insects, they received some preventive and control effects. However, for those occurring in small quantities, insects density is not large, larvae have not spread in areas, by manual removal of the screen can also receive good control effect. American white moth larvae before the age of more than live in the net, the collective foraging, only after the age of four out of the network dispersed foraging. First-generation larvae generally mesh on the middle and lower shoots of trees; second-generation larvae are generally found in trees