72 REPORT OF THE COMMISSIONKti OP AGRICULTURE. 



Neither will the claim be seriously entertained that this insect exer- 

 cises an influence in promoting the health of vines when their foliage 

 is protected, either by a glazed or a boarded covering; that the result- 

 ing loss of foliage, disease, and weakness, when the covering is removed, 

 is caused by their active presence, and that they again abandon the 

 plant, and permit it to assume health and vigor when the protective cover 

 is replaced ; if so, then the much-sought-for and highly-valued remedy ^ 

 for the Phylloxera is readily obtained. \ 



The fact that the Phylloxera is found on the roots of sickly or dying 

 grape-vines is not to be taken as conclusive evidence that the destruction 

 of the plant is solely the work of the insect, since the presence of insects 

 upon diseased organisms is of common occurrence both in animal and 

 vegetable life. 



It is a significant fact that, if- we compare the list of varieties said t 

 be least affected by the Phylloxera with the list of varieties least su> 

 ject to mildew, we will find them to be identical. 



The sum of the whole matter, then, appears to bo this : that who 

 a grape-vine becomes weakened from successive yearly attacks of ml- 

 dew, destroying the foliage, so that the wood or shoots fail to thorougty 

 mature their growth, its vitality is so impaired that what little of Te 

 remains is easily vanquished by the Phylloxera. 



It has been recommended to graft the lona, Delaware, Catawba, fld 

 other varieties infested with the root-louse on roots of the Clin*n, 

 Oporto, Concord, and other kinds that resist its attacks, as a mean of 

 securing immunity from its ravages. It may safely be predicted aat 

 the results expected will not be realized. The same causes that en- 

 dered the lona unprofitable on its own roots will render it unprofilble 

 when grafted on the roots of the Clinton ; and it would not be JJ all 

 surprising if the then weakened roots of the usually robust CUton 

 be found badly infested with the Phylloxera. 



If this method of grafting had proved successful, our vineyards t)uld 

 be planted witli the most esteemed grapes of the world ; but th©xpe- 

 riment has often been made, and as often failed. 



If we look into the history of Europen grape-culture during tli past 

 thirty years, we learn that previous to the year 184.G the crops w(e sat- 

 isfactory and the wine-producing interest prosperous. In that ytr the 

 grape-mildew made its appearance near Paris, and soon spread ov( vine- 

 yards in neighboring districts, from whence it traveled with grearapid- 

 ity over the south of France, Italy, and Hungary. In 1851, t had 

 crossed the Mediterranean, invading Algeria, ^yria, and Asiii.^Iinor, 

 destroying the wine-commerce, and bringing ruin to the ownersf vine- 

 yards. In 1852, it appeared in Madeira, and worked such ftvasta- 

 tion, that in 185G, only 200 pipes of wine were produced aaigainst 

 14,000 pipes produced in 1850 in that island. 



The losses incurred and the destruction occasioned to vindirds by 

 this malady were beyond calculation ; thousands of acres w0 aban- 

 doned, and in those not utterly destroyed the vines were wcaened by 

 the disease and produced only inferior crops. About the ye; 1SG3, it 

 was discovered that the roots of diseased vines were 'covere^with ex- 

 crescences, and continued observations proved that this mal^ "was in- 

 creasing with fatal rapidity. / 



In 18U8 a memoir was presented to the French Academy, ^tailing a 

 new disease, which, the writer thought, was " likely to provanore dis- 

 astrous than the mildew. This new enemy was an insecta minute 

 aphide, which formed yellow parasitic patches on the roots oJhe grape- 

 vine." This " new enemy " has since received the name oiPhylloxera 

 vastatrix. 



