准确预测松毛虫发生期,可为选定最佳防治时期提供依据。1982—84年,我们在建平县对油松毛虫、落叶松毛虫的发生期进行了研究,现将结果初报如下。一、研究方法 (一)松毛虫上树进度观察从3月20日开始,选择两块有代表性的标准地,每块标准地按棋盘式选取100株标准树,在树干胸径处围上宽4cm的塑料环。幼虫开始上树后,每日9—11时、14—16时检查塑料环下阻隔松毛虫的种类和数量,并将环下幼虫清除。上树结束,统计每日上树 Accurate prediction of the occurrence of pine caterpillars may provide the basis for the selection of the best control period. In 1982-84, we conducted a study on the occurrence period of Dendrolimus tabulaeformis and Dendrolimus caterpillar in Jianping County. The results are as follows. First, the research methods (A) of the pine caterpillars on the progress of the tree from March 20 onwards, select two representative standards, each standard by checkerboard select 100 standard trees, trunk width at the trunk wide 4cm plastic ring. After the larvae start on the tree, check the type and amount of the disengaged pine caterpillars under the plastic ring at 9-11 o’clock and 14-16 o’clock daily, and remove the ring larvae. The end of the tree, the statistics daily tree