鸟类对落叶松鞘蛾的抑制作用观察

SUPPRESSION OF THE LARCH CASE-BEARER POPULATIONS BY PREDACIOUS BIRDS IN JILIN

兴安落叶松鞘蛾为东北地区落叶松的主要害虫。1986年3月～1987年10月春秋两季观察:捕食该虫的鸟类有17种。10月间试验用网罩方法阻止鸟类的捕食,到翌年4月调查,未网罩区松鞘蛾密度较网罩区减少33.09％,充分说明自然界鸟类有控制该虫的作用。

In the field studies conducted during 1986 to 1987, seventeen species of birds were found to prey on larch case-bearer, Coleophora dahurica [Lep.: Coleophoridae], a key defoliating pest of larch forest in Jilin Province. In a larch forest stand, 16* trees were covered with a 7x7x4 m wire cage (mesh size=2 cm) in October of 1986 to prevent entrance of birds. Observations in April of 1987 showed that the population density of larch case-bearer in the uncovered check forest was .33.1% less than that on the cage-covered trees, indicating the control effect of birds over the case-bearer populations in nature.