银杏大蚕蛾的发生规律及防治措施

银杏大蚕蛾在湖北地区1年发生1代，以卵越冬，幼虫4-5龄为危害盛期。采取人工摘除虫茧、幼虫3龄前树冠喷Bt乳剂、树干钻孔注射内吸剂以及保护天敌等综合防治措施，能有效地控制该虫的发生与危害，虫口密度由原来的5-8头/100叶下降到0.8/100叶，防治效果达90％以上。

Study on the Occurrence and Control of Dictypoloca japonica

Dictyoploca japonicas reproduce once a year in Hubei province. They live through the winter by their eggs. The fourth to fifth instar larvas are most endangered. Some practical counter -measures, which can obviously control the reproducing and harm of the Dictyoploca japonicas, are extirpating insect cocoon, spraying Bt emulsion on the crown of trees before the third instar larvas, boring in the bole and injecting inside emulsion and protecting natural enemy. The test result shows that the insect density can be reduced from 5-8 insects every 100 leaves to 0.8 insects every 100 leaves.