CHAPTER XXIII 



INSECTS INJURIOUS TO THE GRAPE. * 



The Grapevine Phylloxera f 



THIS insect is native east of the Rocky Mountains, where it 

 has always lived upon wild vines and did not attract attention 

 until it was imported into France about 1859, as it does prac- 

 tically no damage to the native American grapes. It soon spread 

 through the principal wine districts of southern Europe, where it 



caused immense losses and 

 the temporary abandon- 

 ment of vineyards, due to 

 the fact that the European 

 varieties are very suscep- 

 tible and readily succumb 

 to injury by it. It has 

 spread to southern Russia 

 and the adjoining count" 

 FIG. 362. The grapevine phylloxera (Phyl- r i es o f Asia, and Algeria, 

 loxera vastatnx Planchon) : a, true sexual . 



female, the dark colored area indicating and has been carried to 

 the single egg; 6, egg; c shrivelled female New Zea l an d and South 

 after oviposition; a, foot of same; e, rud- 



imentary and functionless mouth-parts. Africa. In this country 

 (After Marlatt, U. S. Dept. Agr.) it is m j ur i ous on l y i n Cal- 



ifornia, where it was imported on French vines about 1874. It 

 was first noticed in Sonoma County and since then has spread to 

 all the principal grape-growing regions north of Tehachapi and has 

 probably destroyed 50,000 acres. 



This aphid exists in several forms, which injure both foliage 

 and roots. On the leaves irregular spherical galls are produced, 

 and the root-inhabiting form produces galls on the roots. The 



* See A. L. Quaintance, Farmers' Bulletin 284, U. S. Dept. Agr. H J. 

 Quayle, Bulletin 192, Cal. Agr. Exp. Sta.; F. Z. Hartzell, Bulletin 331, N. Y. 

 Agr. Exp. Sta. 



t Phylloxera vastatrix Planchon. Family AphididcB. See C. L. Marlatt, 

 Farmers' Bulletin 70, U. S. Dept. Agr., and Quayle, 1. c. 



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