66 HORTICULTURAL SOCIETY OF NEW YORK. 



fornia, where it originated, just as pear-blight, when once intro- 

 duced into California and Colorado, is as contagious and de- 

 structive as in Georgia or Texas. 



The insects that infest grapes know no specific bounds. 

 The rose chafer, the fidia, the leaf-folder, the leaf-hopper, are 

 just as bad in one region as another in which they can endure 

 the winters, and on one species as another with few exceptions. 

 Certain varieties resist, or are distasteful to these insects, and 

 thereby escape, while others are greatly liked and damaged by 

 them. 



The leaf-folder, however, never hurts a vine that has leaves 

 that are glabrous, that is, entirely without pubescence, or down 

 of any kind on the upper side of the leaves. The egg is laid on 

 the upper side and the larva finding no pubescence to tie its webs 

 to, and thus unable to draw the leaf together over it, soon per- 

 ishes in the sun, or is eaten by birds; hence only grapes with 

 leaves more or less downy on upper side of the leaves are dam- 

 aged by the leaf-folder. 



There are some varieties of grapes much less bothered by 

 the leaf-hopper, than others. These generally are the varieties 

 with very firm, dense tissue, such as the Post-Oak grapes of 

 Texas. The fidia and rose chafers make little choice of kinds, 

 and are voracious feeders on the foliage. The Rotundifolia is 

 freest from attack of fungi and insects, in fact almost entirely 

 exempt. 



The Phylloxera comes well under the general rule. It can 

 do little damage to those species of grapes native in the same 

 regions where the Phylloxera is native, yet there is much dif- 

 ference in resistance there. For example, V. rotundifolia is en- 

 tirely immune ; rupestris, vulpina, cinerea, Bcrlandieri, Champini, 

 candic ans, Doaniana, aestivalis and Lincecumii are so high in 

 resistance as to be practically uninjured, though they may be 

 attacked; while Labrusca is low in resistance and is much 

 weakened in clay soils, if infested, and vinifera is entirely non- 

 resistant. It is a native of regions never infested by Phylloxera, 

 until introduced among cultivated vines. 



To have given full lists of resistant and non-resistant va- 

 rieties under each heading of this paper would have been entirely 



