云杉顶芽瘿蚊是近几年甘肃定西地区发现的一种危害云杉顶芽生长点的新害虫。幼虫蛀入云杉顶芽取食生长点。分布面积 4 0 0 0 hm2 ,成灾面积 6 6 7hm2 ,受害株率 97.4 % ,枝条顶芽受害率 83.7% ,10 0 cm长枝虫口密度 9.2 4头 ,虫害指数 58.2 1。为害规律 :人工造林、密度越大、海拔 2 750 m左右、山坡下部、坡位南及西南向受害较重。寄生天敌云杉瘿蚊长尾小蜂寄生率达 6 .39%。 Spruce top bud spider mosquitoes in recent years, Dingxi, Gansu Province, found a harmful spruce bud growth point of new pests. Larvae erode spruce shoots feeding growth point. The distribution area was 4 000 hm 2, the area affected was 6 6 7 hm 2, the rate of damaged plants was 97.4%, the rate of damage of top buds was 83.7%, and the density of 10 0 cm long branches was 9.24. The pest index was 58.2 1. Injury law: Artificial afforestation, the greater the density, elevation 2 750 m or so, the lower part of the hillside, south and south slope to severe damage. Parasitic natural enemies Spruce Anopheles long-tailed wasps parasitic rate of 639%.