根据分离培养和接种试验结果 ,认为白榆死亡是由白榆干枯病感染流行造成 ,病原菌为茎点霉菌。其发展蔓延具有明显的流域特征 :河谷台地、沟坝地、山坡基部发病较重 ;山顶、梁峁地和山坡中、上部发病轻。红足壮异蝽的危害能加重病害的流行和扩展 According to the results of isolation, culture and inoculation, it is concluded that the death of Ulmus pumila was caused by the prevalence of the infection of white-elm dry blight, and the pathogen was Phytopsis. Its development has obvious characteristics of drainage basin: valley terrace, ditch dam, hillside base heavier incidence; the top of the mountain, Liang Gusi and hillside, the upper part of the incidence of light. The dangers of red-footed Bugs can exacerbate the epidemic and spread of the disease