﻿THE GRAPE LEAFHOPPER IN THE LAKE ERIE VALLEY. 3 



study by Prof. C. W. Wood worth. In 1901 Slingerland made a very 

 complete study of the life history of the eastern form, Tij-phlocyba 

 comes Say, and of remedial measures for its control, in the vineyards 

 of Chautauqua County, N. Y., publishing the results in 1904. In 

 1908 Prof. H. J. Quayle conducted a similarly thorough investiga- 

 tion of the western form in the vineyards of California. Investiga- 

 tions of more recent date have been carried on in Chautauqua 

 County, N. Y., by F. Z. Hartzell, in 1912, and by the Bureau of 

 Entomology, United States Department of Agriculture, at North 

 East, Pa. (See Johnson, 1911 and 1912, in Bibliography.) 



ORIGIN AND DISTRIBUTION. 



Since TypMocyba comes and its several varieties are of common 

 occurrence on native grapevines in the wild state almost everywhere 

 that the grapevine is found throughout the United States and Canada, 

 and since -this species is not recorded as occurring in Europe, it is 

 doubtless a native American species. 



It was first recorded from Missouri in 1825, and since that date 

 it has been reported as occurring in destructive numbers in nearly 

 eveiy State in which cultivated grapevines are grown, either in a 

 commercial way or for home use. The following statement by 

 Slingerland in regard to its occurrence is taken from Bulletin 215 

 of the Cornell Experiment Station, pages 84-85: 



In nearly all discussions of the insect enemies of the grape dining the past seventy- 

 five years, the grape leaf hopper has been put in the front rank with the most destruc- 

 tive ones. The records show that it has deserved a prominent place in the rogues' 

 gallery of grape pests in Massachusetts since 1828, in New York since 1856, in Illinois 

 since 1871, in Michigan and California since 1875, in Ohio since 1888, and in New 

 Mexico, Colorado, North Carolina and Minnesota since 1890. Destructive local 

 outbreaks have also occurred in other States. 



FOOD PLANTS. 



During the growing season of the grapevine the grape leafhopper 

 apparently confines its attacks entirely to the foliage of this plant. 

 Early in the spring, however, before the grape leaves commence to 

 unfold, the adult leafhoppers feed on the new foliage of almost any 

 and all plants with which they come in contact, whether it be the 

 foliage of trees and shrubs in woodlands or the weeds and grasses in the 

 more open sod and pasture lands. The following is a list of trees, 

 shrubs, and weeds the foliage of which showed evidence of feeding 

 by the adults in the spring of 1912: Beech, maple, wild cherry, wild 

 apple, hawthorn, dogwood, wild plum, hornbeam, hackberry, honey- 

 suckle, wild grape, Virginia creeper, raspberry, thimbleberry, black- 

 berry, strawberry, goldenrod, nettles, wild columbine, and a great 

 variety of weeds and grasses. Along ravines and woodlands border- 

 ing badly infested vineyards, where large numbers of the adults 



