MORE ABOUT THE GRAPE-VINE PEST. I6i 



We have seen that the Southern Fox (vulpma) is the only species 

 that is totally exempt from both leaf and root lice. This species is of 

 no value whatever in the latitude of St..Louis, and does not flourish 

 above latitude 35°. It cannot, therefore, be made of any avail here, 

 and it is doubtful whether, in the blighted French vineyards, they will 

 be able to profit much by its immunity. I fear that it will hardly 

 flourish even in the extreme southern portion of that country ; while 

 the great difierence between its wood and that of the other cultivated 

 species must render it difficult to successfully graft these upon it. 



Other Preventive Measures. — In planting a new vineyard the 

 greatest care should be taken not to introduce the Phylloxera on the 

 young plants ; and a bath of weak lye or strong soap-suds before 

 planting will, perhaps, prove the best safeguard. 



Remembering that the lice are spreading over the ground from 

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

 a thorough sprinkling of the surface at this season with lime, ashes, 

 sulphur, salt, or other substance destructive to insect-life, will no 

 doubt have a beneficial efiect in reducing their numbers and prevent- 

 ing their spread. 



The insect has been found to thrive less, and to be, therefore, less 

 injurious, in a sandy soil ; while a mixture of soot with the soil has 

 had a beneficial efiect in destroying the pest. I have therefore recom- 

 mended, for the more susceptible varieties, that they be planted in 

 trenches, first prepared with a mixture of sand and soot : an addition 

 of lime and ashes 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. Numerous instances 

 are on record, and have come under my notice, of thrifty vines grown 

 upon trees, or upon houses, with scarcely any pruning, and generally 

 in firm, compact soil; while in the same neighborhood the same kinds 

 of vines, in open culture, have been sickly or have failed. 



Natural Enemies. — There are a number of difierent predaceous 

 insects which serve to keep the leaf-lice in check ; but, as the injury is 

 mostly done underground, it will suffice to enumerate the principal of 

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

 fringe-wing, or thrips, with white wings (Thrips phylloxerm of my MS.). 

 The Q^^^ which is thrice as large as that of the louse, ellipsoidal and 

 with a faceted surface, is deposited within the gall among the more 

 legitimate inhabitants ; and the young Thrips, which difier from their 

 parents not only in lacking wings, but in being of a blood-red color, 

 with only the extremities and the members black, play havoc with the 

 lice. They are active, supple creatures, and turn up menacingly the 

 posterior part of the body when disturbed. They are found in several 

 different kinds of Phylloxera-galls, and do more than any other spe- 

 cies to keep the leaf-inhabiting grape Phylloxera within bounds. 



VOL. V. — 11 



