Spaulding: Tree Diseases in the Eastern States 151 



Myxosporium acerinum Peck 

 Practically the entire season of 191 1 the office of Investigations 

 in Forest Pathology has received specimens of various species 

 of maple which were apparently killed by Myxosporium acerinum. 

 The writer found it in various parts of Vermont upon sugar 

 maple. It is especially noticeable upon street and park trees. It 

 starts upon small branches the size of one's finger but works 

 back until larger ones are affected. Soon it gives the affected 

 tree a ragged appearance and becomes noticed. All the cases 

 seen seemed to have been entirely of the present season's stand- 

 ing. The only feasible method of combating this disease seems 

 to be that of pruning out the affected parts and burning them. 



Phoma piciena Peck 

 A new disease of Norway spruce (Picea excelsa) has for sev- 

 eral years been attracting the attention of pathologists. The 

 writer's attention was called to it by the superintendent of New 

 York State Forests in 1909, but no specimens were seen. Selby 

 has also mentioned a disease which is probably the same one. 

 Peck in his last report named the fungus Phoma piciena which 

 occurred on leaves of red spruce {Picea rubra) in the Adiron- 

 dacks. This summer several specimens of diseased Norway 

 spruce were sent into the office and secured by the writer from 

 the vicinity of Baltimore and Washington. These bore abundant 

 fruiting bodies of a fungus which came nearer to Peck's new 

 species than to any other. Inoculations are being made in the 

 greenhouse. The disease is quite destructive, often completely 

 defoliating large trees and causing their death. Apparently the 

 only practical treatment is that of burning the fallen needles and 

 spraying with suitable fungicides to prevent further spread of 

 the disease. 



Office of Forest Pathology, 

 Bureau of Plant Industry, 



U. S. Department of Agriculture. 



