514 Report op the Mycologist of the 



In 1894 this trouble was sufficiently common on the eastern 

 portion of Long Island to attract the attention of farmers. In 

 1895 it was so common in the same section that potato buyers 

 were constantly on the lookout for i)otatoes so affected, and of- 

 fered a reduced price for them. Frequently, the " pimply " pota- 

 toes, as they are called, sold for as much as five cents per bushel 

 below the regular market price. In 1896 there has been little 

 complaint from farmers and probably it is not as common as in 

 the preceding two seasons. 



When the pimply potatoes were lirst brought to our attention 

 in 1894, we could find no published account of such a trouble — 

 it appeared to be something new. After an examination of the 

 " pimples " and their accompanying " slivers," the conclusion 

 was reached that they probably result from punctures made by 

 some insect while feeding on the growing tubers. This theory 

 was advanced on page 85 of the previously mentioned bulletin.* 

 For the purpose of learning what particular insect is the guilty 

 one, we made, during the past season, an examination of the 

 growing tubers of Green Mountain (the variety so generally af- 

 fected in 1895), in a field where "pimply" potatoes had been 

 abundant the previous season. Our search was immediately re- 

 warded by the discovery of slender white grubs, which were 

 feeding on the young tubers. A brief examination was sufficient 

 to convince us that these little grubs were the cause of the 

 " slivers," it being easy to find them inside of the tubes of the 

 " slivers." The full-grown grubs were scarcely one-sixth of an 

 inch (4mm.) long. When feeding they bore toward the center of 

 the tuber, sometimes almost, if not completely, burying them- 

 selves in the tuber. They do not, however, penetrate to any 

 great distance, since the " slivers " or canals which they make 

 are rarely more than five millimeters in length, the average be- 

 ing about two and nine-tenths millimeters (one-ninth inch). The 

 portion of the body which is outside of the tuber stands straight 

 out at right angles to the surface of the tuber. Whether this is 

 the customary position in feeding we do not know. Perhaps 

 they take this position only when disturbed. Mr. F. A. Sirrine 



* Page 511 of thi« Keport . 



