一、发病区自然概况 此病于1982年首次发现于内蒙古自治区红花尔基樟子松人工林。 红花尔基樟子松林区位于呼伦贝尔盟、鄂温克旗的中南部、新巴尔虎旗的东南部,地处北纬47°54′—48°54′,东径119°46′—120°30′。气候属于半干旱大陆性气候,冬夏气温相差悬殊,年平均气温为-2.1℃,一月份平均气温-26.9℃,绝对最低气温可达-49.3℃。冬季长达八个月之久。平均无霜期约为90—100 First, the nature of the incidence of the general situation The disease was first discovered in 1982 in Inner Mongolia Autonomous Region Hong Huerji-Pinus sylvestris plantations. Honghuaerji Pinus sylvestris forest is located in the Hulun Buir League, Ewenki flag in the south-central, the new Baluchi flag southeast, is located at latitude 47 ° 54’-48 ° 54 ’, east longitude 119 ° 46’-120 ° 30’ . The climate belongs to the semi-arid continental climate. There is a great difference between summer and winter temperatures. The annual average temperature is -2.1 ℃. The average temperature in January is -26.9 ℃. The absolute minimum temperature can reach -49.3 ℃. Winter up to eight months. The average frost-free period is about 90-100