334 The Ohio Naturalist. [Vol. XI, No. 6, 



of which we have about a hundred species, now known, in North 

 America, and well worth being studied, are of much smaller size, 

 the mussels being 1.5 to 20 mill, long when mature; their hinges 

 are more complete; the mantle is less open and the siphons are 

 closed, and tubes; the four branchiae are differently arranged; the 

 young are developed in a special, brood pouch on the inside of 

 the inner branchiae on each side; the young, when mature, are 

 much larger than the glochidia of the Unionidae and fully 

 developed. 



New Philadelphia, Ohio. 



THE OCCURRENCE OF APPLE BLOTCH IN OHIO. 



W. O. Gloyer. 



In the early part of September of this year there came an 

 inquiry to the Department of Botany of the Ohio Agricultural 

 Experiment Station from an orchard grower of Sharon, Noble 

 County, seeking advice in regard to the blotched appearance of 

 some of the apples found in his orchard. Examination of the 

 specimens, by Mr. Arzberger, of this department, revealed the 

 presence of the Apple Blotch, PhyUostlcta soUtaria, E. & E. This 

 disease was reported by Scott* in 1909 as being quite prevalent 

 in our southern states, causing a great deal of dainage in the 

 orchards infected. Investigations in the orchards in the vicinity 

 of Wooster showed its presence on a local variety of apple known 

 as "Butter Apple." All the trees of this variety in the orchard 

 were infected to about sixty per cent of their crop, while other 

 trees under similar conditions were immune. 



Inquiries and inspection of the orchards in our southern 

 counties revealed the fact that the apple blotch was quite prev- 

 alent in sprayed as well as unsprayed orchards. Usually one 

 variety in an orchard .suffers to a great degree while the remainder 

 of the orchard is not infected. In one orchard, for instance, 

 twenty barrels of Pippins were infected to about ninety per cent, 

 while the other varieties were immune. The investigations in 

 Lawrence, Gallia and Jackson Counties showed that Phyllosticta 

 solitaria occurred frequently on Smith's Cider, Baldwin, Ben 

 Davis, Stark, Pippin, and Rome Beauty. Often, as was the case 

 with the Pippin, the entire crop was laiined by this disease. The 

 disease has also been found in Wayne, Noble, and Athens Counties. 



The fungus is not only found on the fruit, but its presence is 

 also noted on the leaves and twigs; nevertheless, the disease is not 

 suspected in the orchard unless the disease has made itself evident 

 on the apples. The dark-brown stellar spots (Figs. 1 and 3), 



U. S. Bull. 144, Bureau of Plant Industry. 



