美国白蛾(Hyphantria cunea Drury)自传入我国后,几年间为害范围已达十个市、县,并有继续蔓延趋势。由于该虫繁殖力强、食性杂、幼虫具暴食性,对林木、果树和蚕业生产威胁极大。同时近年来施用农药数量及浓度不断增加影响生态平衡。而利用核型多角体病毒防治,杀虫效果好,具有作用专一、安全、持久,又不污染环境的特点。我们于1979年8月在丹东市郊区分离到该病毒,经初测对美国自蛾幼虫有较强的感染力。又对病原形态结构和感染力测定进行了较系统地研究,现报道如下。一、材料和方法(一)材料供试病毒:取第一代和第二代罹病之美国 Since the introduction of Hyphantria cunea Drury into our country, the damage range of the Hyphantria cunea Drum has reached 10 cities and counties in the past few years and has continued to spread. Due to its high reproductive capacity, complex diet and larvae, it poses a great threat to the production of trees, fruit trees and sericulture. In the meantime, the quantity and concentration of pesticides applied in recent years have been constantly increasing, affecting the ecological balance. The use of nuclear polyhedrosis virus prevention and control, insecticidal effect, with a role-specific, safe, long-lasting, but also does not pollute the environment. We isolated this virus in the suburbs of Dandong City in August 1979, and the initial test showed a strong infectivity to moth larvae in the United States. Also on the pathogen morphology and infectivity determination conducted a more systematic study, are reported below. First, materials and methods (A) materials for the test virus: Take the first and second generation of the United States