采用 L9(34 )混合正交设计 ,对 3个施药时期、 3种药剂、 3个浓度梯度进行化学防治落叶松红瘿球蚜效果比较 ,筛选出防治该虫的最佳时期、最佳药剂和最佳浓度。防治试验结果表明 ,用50 %抗蚜威可湿性粉剂防治该虫效果最好 ,防治最佳时期为越冬虫产卵前期 ,即 5月下旬至 6月上中旬 ,防治最佳浓度为 1∶ 2 0 0 0倍 ,且成本较低 The orthogonal design of L9 (34) was used to compare the chemical control effects of three chemical pesticides and three concentration gradients on the larch population of Aphis gossypii Glover. The optimum period for controlling the insects was screened out. And the best concentration. The results of the prevention and cure test showed that 50% of the pirimicarb WP had the best control effect. The best control period was the pre-oviposition of the overwintering pests, that is, from late May to the middle of June, the best control concentration was 1: 2 0 0 times, and the cost is lower