54 



Insects. 



BUSHBERG CATALOGUE. 



Phylloxera. 



TYPE RADICICOLA : a, shows a healthy root ; b, one on 

 which the lice are working, representing the knots 

 and swellings caused by their punctures ; c, aroot that 

 has been deserted by them, and where the rootlets 

 have commenced to decay ; d, d, d, show how the lice 

 are found on the larger roots ; e, female pupa, dorsal 

 view; g, winged female, dorsal view. 



The editors of this Catalogue could not help, how- 

 ever, to doubt the theory of a relative susceptibility, 

 or a greater or less power of resistance, in various va- 

 rieties of our American vines. The Catawba, the Dela- 

 ware, were among those considered most sensitive to 

 the attacks of the insect. But their very existence 

 after so many years of their cultivation in the home of 

 the Phylloxera, and their vigorous and healthy growth 

 in some Phylloxera-infested localities in France, con- 

 tradict this assumption. And now most of those who 

 gave special attention to this question, and have had 

 the opportunity to test it both here and in Europe, 

 are firmly of the opinion that all purely American varie- 

 ties completely resist the Phylloxera, and can succeed 

 in spite of the insect, provided they are placed in loca- 

 tions suitable as to soil and climate. 



We see in the general resistibility of our purely na- 

 tive American vines against the Phylloxera, a remark- 

 able verification of that law which Darwin has so ably 

 established and aphoi istically expressed, as "THE SUR- 

 VIVAL OF THE FITTEST." 



Prof. Riley, in explaining "why the insect is more 

 injurious in Europe than here," says: " There exists 

 a certain harmony between the indigenous fauna and 

 flora of a country ; and our native vines are such as, 

 from their inherent peculiarities, have best withstood 

 the attacks of the insect. The European vine, on the 

 contrary, succumbs more readily, not only because of 

 its more tender and delicate nature, but because it 



has not been accustomed to the disease there being, 

 doubtless, a parallel between this case and the well- 

 known fact that diseases and parasites which are com- 

 paratively harmless among peoples long accustomed 

 to them, become virulent and often fatal when first 

 introduced among hitherto uncontaminated peoples. 

 Then the particular natural enemies of the insect which 

 belong to its own class, and which in this country 

 help to keep it within bounds, are lacking in Europe ; 

 and it will require some time before the closely allied 

 European predaceous species will prey upon and check 

 it there to the same extent. The Phylloxera will, also, 

 all other things being equal, have an advantage in those 

 countries where the mildness and shortness of the win- 

 ter allow an increase in the annual number of its gen- 

 erations. Finally, the differences in soil and in modes 

 of culture have no insignificant bearing on the ques- 

 tion in hand. Though Phylloxera, in both types, is 

 found on our wild vines, it is very doubtful if such 

 wild vines in a state of nature are ever killed by it. 

 With their far-reaching arms embracing shrub and 

 tree, their climbing habit unchecked by the pruner's 

 knife, these vines have a corresponding length and 

 depth of root, which render them less susceptible to 

 injury from an under-ground enemy. Our own method 

 of growing them on trellis approaches more nearly 

 these natural conditions than that employed in the 

 ravaged French districts, where the vines are grown 

 in greater proximity and allowed to trail upon the 

 ground, or are supported to a single stake." 



Again, after speaking of the large numbers of winged 

 females rising from the ground during late summer 

 and fall, he adds : " The winged female Phylloxera is 

 wafted about, and will lay her eggs, or, in other words, 

 deliver herself of her progeny, wherever she happens 

 to settle. If this be upon the grape-vine, well and 

 good the young live and propagate; if upon other 

 plants, they perish. We thus have the spectacle of a 

 species annually wasting itself away to a greater or 

 less extent, just as in the vegetable kingdom most 

 species produce a superabundance of seed, the larger 

 portion of which is destined to perish. Thus in the 

 thickly planted wine districts of France few winged 

 insects would fail to settle where their issue could sur- 

 vive, while in America an immense number annually 

 perish in the large tracts of other vegetation interven- 

 ing between our vineyards." 



Under the stimulus of a large reward (300,000 francs) 

 appropriated for the purpose by the French Govern- 

 ment, innumerable plans have been proposed and 

 experiments made, but no remedy has yet been discov- 

 ered which gives entire satisfaction, or is applicable to 

 all conditions of soil.* Submersion is an efficacious 

 remedy, but to be effective the field must be covered 

 with water one foot deep during eight weeks, Novem- 

 ber and December being considered the proper period ; 

 a less complete submersion is useless, and on most 

 and especially on the best hilly vinelands such sub- 

 mersion is impracticable. A large admixture of sand 

 in the soil is also of service, as the root-louse does not 

 thrive on sandy soils. This was first discovered by 



* La lutte centre le phylloxera. (The straggle against 

 the Phylloxera) by J. A. Barral, 1 vol., Paris, 1883, is the 

 latest and most complete work on this subject. 



