159 



new infestations in Vermont and emphasizes that "[butternut canker] disease has 

 eliminated most of the butternut in the Southern region." Unlike chestnut, butternut 

 will not sprout from the root crown when the top is killed by cankers. Seedlings and 

 young sprouts are killed by the disease in addition to mature trees (Prey and Kuntz 

 1982). Therefore, when butternut canker destroys a population, that particular gene 

 pool is lost forever as there is no possibility for reproduction. 



rvalurat range oj butternut in ttu UnttM ^tat£i 



Tl>c dev-astation of butternut is occurring so rapidly that the species is currendy a Fed- 

 eral Category 2 candidate for listing under the Endangered Species AcL In the north- 

 ern National Forests (Forest Service, Region 9), it has been listed as a sensitive 

 species. In soudiem slates (Forest Service. Region 8), die National Forests in Mississippi 

 consider buiicrnui a sensitive species, and other southern National Forests have reconi^ 

 mended the tree for sensitive species status. 



No known cures exist for the disease. Research to develop a disease-resistant tree be- 

 gan in 1989. years after the first infestation was documented. A few putative resistant 

 trees have been found in various locations and are presently being evaluated 

 (Anderson, personal communication). 



Beech Bark Disease 



American beech (Fagus grandifolta) is an important species in climax forests of eastern 

 North America. The tree is utiUied for lumber and pulp, and provides hard mast for wild- 

 life species. Beech populations in the northeast have been infested with a disease com- 

 plex that has caused extensive mortality or reduced productivity. This disease has now 

 been found as far south as the Great Smoky .Mountains National Park (Rhea, personal 

 communication). The disease complex is composed of tj e exotic beech scale (Crypto- 

 cocnis fagisuga) and fungi of the Nectna genus. ;V. galhgma and/or N. coccirua var. /agi- 

 nata. The fiingi enter the tree through holes in the bark caused by scale infestation. The 

 resulting cankers can kill or dis6gure the infested tree (Houston and Valentine 1988). 



The beech scale was inadvertenUy imported into North America on European beech 

 (Fagus sylvatica) nursery stock (Hawbolt 1944). By 1932. a survey in Maine revealed 



