128 STATE POMOLOGICAL SOCIETY. 



INSECTS. 



"We are frequently asked the question : Is grape rot not caused by insects; 

 I have seen the Phylloxera vastatrix at the roots of many of the grape vines in 

 New Jersey, not only in the soil composed of sandy loam, but also in coarse 

 sand, and gravel with a slight admixture of sand. But in some cases where 

 the rot was found in great abundance there was an absence of Phylloxera, and 

 again where rot was found in a much smaller degree I found Phylloxera. It 

 therefore appeared, so far as my observation extended, that Phylloxera had 

 little to do with the rot on this occasion, especially with the rot of the Concord 

 grape. 



There is no doubt, however, that the effect of the phylloxera at the vine 

 roots is to produce great irritation which in some cases very materially debili- 

 tates the plant or vine attacked by it. Indeed all of the vine insect pests are 

 contributory to vine disease more or less, and the only remedy for disease thus 

 caused is the destruction of the insect. 



'^THRIP." 



There is an insect commonly known as **thrip," a little hopping insect 

 which infests the under side of the leaves and proves very destructive to them, 

 especially when great protection is afforded it, as by high wooden fences, walls, 

 or houses. Owing to the sucking propensities of this insect the leaves become 

 blanched and have a scorched appearance, and the total destruction of foliage 

 often prematurely occurs in vines thus protected, especially in cities. AVheu 

 we take into account the importance of the leaves in elaborating food for the 

 vine, the effect of their loss upon its bearing powers may be better compre- 

 hended. 



A plant which remains vigorous until the time of its natural rest occurs, will 

 have stored up in its branches the food necessary for the succeeding year. 



An American mycologist in a late paper on the ^'Peronospora viticola " of 

 the American vine, says : '^One would naturally suppose that a fungus so com- 

 mon as Peronospora, which often is found on every leaf of a vine, would have 

 an injurious effect wyion the grape crop. Such however is not the case. The 

 fungus does not attack the grapes themselves, nor does it at least in New Eng- 

 land, appear until the first of August, and its withering effect upon the leaves 

 is not very evident before September. 



As far as out of door grape culture in the northern States is concerned we 

 are inclined to believe that practically no harm is done by Peronospora viticola, 

 but that on the contrary the fungus is really beneficial. Our native vines have 

 a luxuriant growth of leaves, and the danger is that in our short summers the 

 grapes will not be sufficiently exposed to the sun to ri})en, but the Peronospora 

 arrives with us at a period when the vine has attained its growth for the season, 

 the important point being then to ripen up the grapes which are concealed in 

 the foliage, by shriveling up the leaves. The Peronospora enables the sun to 

 reach tlie grapes without loss to the vine, as is shown by the fact that the vines 

 contnme to live on year after year without ap[)arent injury. 



An unsuspecting person would be apt to suppose from this statement that 

 the fungus Peronospora viticola was a great boon to the grape growers of the 

 New England States, but the growers themselves, who speak from practical 

 experience, tell a very different story; and so also do the scientific horticultur- 

 ists of New England, as well as those of all other sections of the country. The 

 fact is that out of door grape culture is at a discount in New England for 



