B. r. I.— 2C,7. 



INSECT AND FUNGOUS ENEMIES OF THE GRAPE 

 EAST OF THE ROCKY MOUNTAINS. 



INSECT ENEMIES. 



All of the important insect enemies of the grape in the TTnited States 

 at the present time are native American species, feeding originally, as 

 they do at the present day, on various wild species of grapes and 

 related plants. With the planting of vineyards and the extension of 

 the grape-growing industry many species attacked also the cultivated 

 varieties, and some few have become exceedingly troublesome pests. 

 Perhaps no horticultural crop so well illustrates the serious loss wliich 

 may result from native species of insects attacking cultivated varieties 

 of their natural wild food plants as does the grape. As a rule, varieties 

 with a preponderance in parentage of the European grape {Vitis 

 vinifera) are not vigorous growers in the Middle and Eastern States 

 and suffer to a greater degree from insect attack than varieties with 

 parentage of American Adnes, But these latter are not exempt 

 and, with the exception of one or two insects, are equally subject to 

 attack. The principal exception to be noted is the grape phylloxera, 

 an apliide or ''plant louse" wliich infests the roots and also the leaves 

 of the grape and is especially injurious to vinifera or European varieties. 

 Several species of American grapes and some of their hybrids and 

 varieties, and other kinds to a less degree, are resistant to attack from 

 this insect, and these are used as grafting stock for vinifera varieties in 

 California and Europe, where the insect has been and is especially 

 troublesome. It has been suggested that certain species or varieties 

 of American grapes ar^ resistant to the grape root-worm also, and 

 although there is no evidence bearing on the question, the matter is of 

 sufficient importance to warrant careful investigation. 



Of the two hundred or more species of insects known to feed upon 

 the grape in the United States, those treated herein include, with the 

 exception of the phylloxera, those of prmcipal importance, namely, 

 the grape root-worm, grape berry moth, grape curculio, grape leaf- 

 hopper, grape leaf-folder, grapevine flea-beetle, and rose-chafer. 

 Grape insects are not less amenable to treatment than insect pests of 

 other fruit crops, and the vineyardist may confidently expect to be 



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