60 



From Mr. Riley's synopsis of experiments and observations we gather the following state- 

 ment respecting the different varieties of grape: — 



EtJROPEAN Vine ( Viiif: vinifera) — Rarely subject to leaf-gall, but it generally succumbs 

 to the attacks of lOot lice after a few years. 



River-bank Vine {F. riparia) — The Cornucopia, Alvey and Othello suffer very little 

 or not at all from Leaf galls, but to a considerable extent from Koot-lice. The Clinton and 

 Taylor are very subject to the Leaf-galls, but from the great vitality of their roots they do 

 not succumb to the attacks of the Root,-lice. The Gold'^n Clinton and Louisiana do not suf- 

 fer much from either. The Marion a good deal affected by the former, but little by the lat- 

 ter. The Delaware suffers considerably from both. 



Summer Grate (F. aestivalis) — The Cunningham, Norton's Virginia, and Rutlander 

 suffer not at all from the Leaf-gall, and very little from the Root-lice. The Herbemont and 

 Gynthiana suffer slightly from both. 



Northern Fox Grape (Labrusca) — The Challenge, Dracut Amber, Israella, Martha, 

 Northern Muscadine and Wilder, are not subject to the Leaf-gall, and only slightly to the 

 root-lice. The Diana, Goethe, Hartford, Isabella, Ives, Maxatawney, North Carolina, Re- 

 becca and Salem are also free from the Leaf-gall, but have the Root-lice more abundant and 

 suffer more from its attacks. The Catawba and lona do not suffer from the Leaf-gall, but 

 are most subject to the Root-lice The Concord has the Leaf-galls but rarely, and dons not 

 suffer much from the Root-lice ; the Creveling also is usually free from the former, but suf- 

 fers much more from the latter. 



Southern Fox Grape. — This species is entirely free from the Phylloxera in any 

 form. 



The above enumeration is founded principally upon Mr. Riley's observations in the cen- 

 tral portion of Missouri ; he has also examined many of the varieties in Kansas, Illinois, New 

 Jersey, Pennsylvania and New York. The Arnold's hybrids, which he has examined, all 

 suffer, he states, but some of them more than others. 



Means of Coping with the Disease. — Grafting the more susceptible varieties on 

 the roots of those that have a greater power of resistance, would probably counteract the 

 disease to a great extent. This plan is ujw being tried on a large scale, but it will be neces- 

 sary to wait a year or two before any positive conclusions can be obtained. 



" In planting a new vineyard the greatest care should be taken not to introduce Phyl- 

 loxera on the young plants, and a bath of weak lye or strong soap suds before planting will, 

 perhaps, prove the be^t safeguard. Remembering that the lice are spreading over the 

 ground from July till fall, and principally in the months of August and September, a 

 thorou2;h sprinkling of the surface with lime, ashes, sulphur, salt or other substance destruc- 

 tive to insect life, will, no doubt, have a beneficial effect in reducing their numbers and pre- 

 venting thcii- spread. 



The insect has been found to thrive less and to be, therefore, less injurious in a sandy 

 soil ; while mixture of soot with the soil has had a beneficial effect in destroying the pest. It 

 is, therefore, recommended for the more susceptible varieties, and that they be planted in 

 trenches first prepared with a mixture of sand and soot. An addition of lime will also prove 

 beneficial. There is every reason to believe that vines are rendered less susceptible to the 

 disease by a system of pruning and training that will produce long canes and give them as 

 nearly as possible their natural growth. 



Natural Enemies. — There are a number of predaceous insects which serve to keep 

 the leaf-lice in check ; but as the injury is mostly done underground it will suffice to enu- 

 merate the principal of these in this connection. The most efficient is a black species of 

 Fringe-wing or Thrips with white wings (Thrips Plyllcixeni'). They are found in several differ- 

 ent kinds of Phylloxera galls, and do more than any other species to keep the leaf inhabit- 

 ing species within bounds." 



The next most efficient aids in the destruction of the leaf-lice are the lace-winged flies 

 (Chrysopa) ; the lady birds (Coccinella) ; certain Syrphus fly larvae ; a few true bugs and 

 other insects. 



The enemies known to attack the Phylloxera underground are, naturally enough, fewer 

 in number. In one instance, Mr. Riley relates, I have found a Scymnus larva at the work 

 six inches below the surface, and there is a Syrphus fly, whose larva lives under-ground and 

 feeds both on the apple-tree root-louse and on this grape root-louse. Wonde rful indeed 



