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BULLETIN 19, U. S. DEPARTMENT OE AGRICULTURE. 



work a great amount of injury has not been observed. The other 

 species most commonly found associated with T. comes is T. tricincta 

 Fitch (fig. 6,5). This species, when present, is more likely to be found 

 on the foliage of Delaware, Catawba, Brighton, and some of the wild 

 species of grapevine growing along ravines or in woodlands. It 

 is readily distinguished from comes by the larger size and by the 

 fact that it has three broad black bars situated as follows: One 

 just back of the head, another about midway across the elytra, and 



Fig. 6. — The two species of grape leafhopper most common in vineyards of the Great Lakes Region: 

 a, Typhlocyba comes; b, Typhlocyba tricincta. Greatly enlarged. (Original.) 



the third at the tips of the elytra. Nymphs of tricincta (fig. 7) 

 have two black spots back of the eyes and two on the thorax. 



While making trips through the vineyard areas along the shore of 

 Lake Erie as far west as Sandusky, Ohio, it was observed that in the 

 Ohio vineyards east of Cleveland Typhlocyba tricincta was present in 

 greater numbers than in the vineyards of Chautauqua County, N. Y., 

 and of Erie County, Pa., although more than 80 per cent were still 

 Typhlocyba comes. In the vineyards west of Cleveland T tricincta 



