38 



BULLETIN 1103, U. S. DEPARTMENT OF AGRICULTURE. 



County and eastward. In South Dakota the infested region was con- 

 tinuous with that in North Dakota, extending westward to the mid- 

 dle of McPherson County through Hand County to Charles Mix 

 County. By the middle of July in South Dakota many of the 

 potato fields were practically dead as a result of " hopperburn." 



In Iowa this insect was recorded as being one of the principal 

 causes of low yields of potatoes. At Oelwein. in Fayette County, 

 the crop was almost a complete failure. 



In the New England and Middle Atlantic States quite serious in- 

 festations were recorded from eastern Vermont and western Xew 

 Hampshire, along the Connecticut Elver Valley, the infestation be- 

 ing continuous with that extending through central Massachusetts 



Fig. 20. — Geographical distribution of the potato leafhopper in destructive numbers in 

 the Fnited States in 1921, shown by shaded areas. Dots are localities of very seveiv 

 infestation ; circles, localities from literature. 



and the greater part of Connecticut and Rhode Island. A similar in- 

 festation extended along the western side of Vermont, running 

 parallel with the Hudson River Valley infestations in New York. 



In New York serious outbreaks were recorded from central and 

 western sections. Long Island, and Ulster County, very severe in- 

 festations being recorded from Chautauqua, Genesee, Wayne, Steu- 

 ben, Onondaga, Ulster, and Suffolk Counties. 



In Pennsylvania serious outbreaks were recorded up the Sus- 

 quehanna River Valley. 



West Virginia recorded an outbreak in the Ohio River Valley con- 

 tinuous with that in Ohio, and also recorded that this insect was 

 much more abundant than usual in Tucker Countv. 



