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柳毒蛾(Leucoma candida)属毒蛾科,幼虫为害杨、柳等树,在保定,室内饲养一年可发生四代。1983年5月至9月,我们分别在保定、望都、易县、承德、宣化等地的杨树上采集到感染NPV的柳毒蛾病死幼虫。有的地方幼虫发生流行病,病死虫用腹足倒挂于树枝、树干上;有的死于裂开的树皮内。病死虫体肥肿,内部组织液化,表皮易破裂,裂开后流出灰褐色浓体液。取浓体液在相差显微镜下观察,可见到折光性很强的多角体。室内用1×10~7PIB/ml浓度浸叶饲喂2—3龄幼虫,初步结果表明,柳毒蛾NPV对该宿主幼虫具有较高的致病
Leucoma candida is a genus of moths, larvae damage poplar, willow and other trees in Baoding, indoors can occur four generations a year. From May to September 1983, we collected the dead larvae of the blight on NPV in poplars in Baoding, Wangdu, Yixian, Chengde and Xuanhua, respectively. Occurrence of larvae in some places, dead worms with belly and foot hanging upside down on the branches, the trunk; some died in the cracked bark. Diseased dead worm body, internal tissue liquefaction, epidermal easily rupture, split out after the gray-brown concentrated liquid. Take concentrated solution under phase contrast microscopy, we can see a very strong polyhedron. The second and third instar larvae were infested with 1 × 10 ~ 7PIB / ml indwelling leaf in laboratory, and the preliminary results showed that NPV of larva was highly pathogenic to this host larvae