MacKenzie M, Iskra A J
USDA Forest Service, Morgantown. WV. 26505.
Plant Dis. 2005 Feb;89(2):203. doi: 10.1094/PD-89-0203A.
Beech bark disease (BBD) is a two-part disease complex. It first requires the feeding of an initiating insect scale and is only fully developed when scale-altered bark becomes infected by one of two Neonectria species. In Ohio, there was a 19-year lag between discovery of the initiating scale insect and the development of BBD. In September 1984, the BBD-initiating scale (Cryptococcus fagisuga Lind) was discovered in the Holden Arboretum, Geauga County, OH (2). Nineteen years later (December 2003), A. Iskra discovered the exotic BBD-causing fungus, Neonectria coccinea (Pers.:Fr.) Rossman & Samuels var faginata Lohman, Watson & Ayers, on American beech (Fagus grandifolia Ehrh.) in the Holden Arboretum. In 1934, Erlich (1) reported that there was normally a delay of at least 1 year between the appearance of the scale and the first appearance of the Neonectria spp. fungus. In the years immediately after the first report of the scale in Ohio (2), pathologists and arboretum staff made frequent visits to the site in an attempt to find Neonectria spp. fruiting. After a decade of searching, these visits became more infrequent. However, it was on one of these visits that A. Iskra found the fungus. He found it on only four trees, none of which had the extensive bark cankering common in chronic Neonectria spp. infections. In North America, the two species of Neonectria that have been involved in BBD mortality are the native N. galligena (Bres.) Rossman & Samuels, or the exotic N. coccinea var faginata. In the absence of beech scale infestations, reports of the native N. galligena infecting American beech are few. Yet, in West Virginia, western Pennsylvania, Michigan, and possibly North Carolina, the fungus first associated with the killing front has been the native N. galligena and not the exotic variety, N. coccinea var faginata. To our knowledge, this is the first report of BBD in Ohio and it is unique because the associated fungus is the exotic variety. References: (1) J. Erlich. Can. J. Res. 10:593, 1934. (2) M. E. Mielke et al. Plant Dis. 69:905, 1985.
山毛榉树皮病（BBD）是一种由两部分组成的病害复合体。它首先需要一种起始介壳虫的取食，并且只有当被介壳虫改变的树皮被两种红颈菌属真菌之一感染时才会完全发展。在俄亥俄州，从发现起始介壳虫到BBD的发展有19年的时间间隔。1984年9月，在俄亥俄州乔加县的霍尔登树木园发现了引发BBD的介壳虫（Cryptococcus fagisuga Lind）（2）。19年后（2003年12月），A. 伊斯克拉在霍尔登树木园的美国山毛榉（Fagus grandifolia Ehrh.）上发现了外来的导致BBD的真菌，即红颈菌（Neonectria coccinea (Pers.:Fr.) Rossman & Samuels var faginata Lohman, Watson & Ayers）。1934年，埃利希（1）报告说，介壳虫出现和红颈菌属真菌首次出现之间通常至少有1年的延迟。在俄亥俄州首次报告介壳虫后的几年里（2），病理学家和树木园工作人员经常前往该地点，试图找到红颈菌属真菌的子实体。经过十年的搜寻，这些访问变得不那么频繁了。然而，正是在其中一次访问中，A. 伊斯克拉发现了这种真菌。他只在四棵树上发现了它，这些树都没有慢性红颈菌属真菌感染中常见的广泛树皮溃疡。在北美，与BBD致死有关的两种红颈菌属真菌是本土的N. galligena（Bres.）Rossman & Samuels，或外来的N. coccinea var faginata。在没有山毛榉介壳虫侵扰的情况下，关于本土的N. galligena感染美国山毛榉的报告很少。然而，在西弗吉尼亚州、宾夕法尼亚州西部、密歇根州以及可能的北卡罗来纳州，最初与致死前沿相关的真菌是本土的N. galligena，而不是外来品种N. coccinea var faginata。据我们所知，这是俄亥俄州首次报告BBD，而且它很独特，因为相关真菌是外来品种。参考文献：（1）J. 埃利希。《加拿大研究杂志》10:593，1934年。（2）M. E. 米尔克等人。《植物病害》69:905，1985年。
