据报道河北省雾灵山林管局六里坪林场,从1978年开始在树干上围挂塑料帽用于除治松毛虫虫源树及虫情测报,并在3.5亩独立小区内进行防除试验,试验结果有虫株率能降低98％以上。每亩工料费合计1.50元。北京西山林场在树干上挂塑料帽阻止幼虫上 It is reported that Wulingshan Forest Management Station in Liuli Ping Forest Farm in Hebei Province, from 1978 onwards in the trunks hanging plastic cap for the removal of pine tree caterpillars and insect detection of insects, and 3.5 acres of independent community control tests, The result of the experiment is that the worm strain rate can be reduced by more than 98%. Fees per acre total fee of 1.50 yuan. Beijing Xishan Forest hangs plastic caps on tree trunks to stop larvae