4 MASS. EXPERIMENT STATION BULLETIN 368 



Cieager (9) reports that, according to his experiments, the most common 

 method of fungus entrance is through wounds in the leaves. 



McCormick (18) reports that Ccphalosporium wilt is the disease most fre- 

 quently found in specimens of elm received at the Connecticut Agricultural 

 Experiment Station. She also reports the survival and apparent health of two 

 trees eleven years after successful inoculation, although the causal fungus has 

 been isolated consistently from both trees during the period since inoculation. 



Beattie (4) reports that while the disease seems to be very prevalent in the 

 United States, it is unknown in England. 



A map and table, showing the geographical distribution of the disease and the 

 number of trees known to be affected in Massachusetts during 1935 and 1936 

 were published by the junior author in 1937 (14). 



A pycnidial stage of the fungus has been reported by V'errall and May (25), 

 and they have placed it in the genus Dothiorella. Creager (9, 10) also reports 

 pycnidia as being abundant both in nature and in laboratory cultures. Reports 

 on the finding of pycnidial stages of fungi associated with some other diseases 

 affecting woody parts of elms in the United States include Phomopsis sp.^, Coni- 

 othyriiim nlmi (12), Sphazropsis ulmicola (13), and Vermicularia sp. (12). 



Figure 2. The Black Areas Show Geographical Distribution of Ccphalosporium sp., 1935-1939. 



FIELD OBSERVATIONS 



Limited field observations by the writers have been supplemented by extensive 

 field notes of trained scouts and other collaborators. During the five years 

 1935-1939 the Shade Tree Disease Laboratory at Massachusetts State College 

 received approximately 7000 specimens for diagnoses. Of this number approx- 

 imately 75 percent were collected from elm trees. The total number of trees 

 found to be infected with Cephalosporium sp. was 501. Figure 2 shows the 

 geographical distribution of the fungus within the state. 



The disease is characterized by a gradual wilting and drying of the leaves, 

 especially on the terminal twigs. In the summer the appearance of yellowed 



^Richmond (23) proved ascigerous form of this Phomopsis to be Dinf)oi-llie sp. 



