早期落叶病毒在我区主要危害落叶松属树种,是由子囊亚门中的球毒菌所引起。属强寄生性真菌。病症发生在叶片上,受害叶片开始在尖端或近中央部分出现直径不超过1毫米,浅黄色的小斑点2～3个,以后病斑逐渐扩大到2毫米左右,颜色变成赤褐色,边缘稍呈淡黄色,7月份病斑增多,扩大,相互连接,多数叶片将近全部或1/2以上变为赤褐色。远看整个树冠呈 Early deciduous virus in our area the main hazard larch species, is caused by the ball of Ascochyta sublobate bacteria. Is a strong parasitic fungi. The disease occurred in the leaves, the victim leaves began in the tip or near the central part of the diameter of not more than 1 mm, light yellow spots 2 to 3, after the lesion gradually expanded to about 2 mm, the color into auburn, slightly edge Yellowish, spot enlargement, enlargement, interconnection in July, most leaves almost all or more than 1/2 turn auburn. See the entire crown from afar