The Grape- Vine 



2&7 



PHYLLOXERA. THE WINGED 

 INSECT 



tubercles, which later become dark and rotten, and on 

 the tubers may be found large numbers of the phyl- 

 loxera itself — minute yellowish-brown creatures, pro- 

 vided with six legs and a strong, tubular proboscis, by 

 means of which they pierce the bark of the root and 

 rob the plant of its sap. These insects, are wingless 

 females, which from March to October lay enormous 

 numbers of eggs which give rise to females exactly 

 similar to themselves. During the summer, however, a 

 second form of insect appears among the root-dwellers, 

 although the eggs from which they are hatched possess 

 no characteristics to distinguish them from the others. 

 The new insect, when mature, is provided with wings, 

 and, after emerging into the air through the soil, flies 

 about the vineyard during the summer and early 

 autumn, feeding upon the juices of the leaves and twigs 

 of the vines. The winged insects or nymphs, which 

 are all females, lay their eggs on the leaves, and in . 

 the next generation we have the appearance of insects 

 of both sexes, male and female, neither of which 



possess wings. The life of these forms is very short, / . \ 



and is taken up with producing a new generation of 

 females, also wingless, which are known as the stock- 

 mothers. These latter attack the tissue of the leaves, 

 forming galls on the under surface, where they 

 take, up their abode. We at last complete the com- 

 plicated life history of this pest, for the numerous 

 progeny of the stock-mothers emerge from the galls, 

 and, descending to the roots, become the root-dwelling 

 forms which once more start the vicious cycle. fJ 



Although the attacks of phylloxera frequently 

 result in the ruin of the vineyard affected, the vigneron 

 is not entirely without remedy. America is the home 

 of the pest, and it seems but just of Nature to provide 

 from the same country the salvation of the afflicted 

 vine-grower. Many of the native vines of America 

 have become immune, as it were, from the attacks of 

 the insect after long ages of susceptibility, and the 

 remedy which has met with the greatest amount of 

 success consists in rooting up and destroying all 

 diseased plants, and planting stocks of the American 

 " phylloxera-resisting " varieties. When once estab- 

 lished, cuttings of the local vines are grafted on to the 

 stocks, so that we have what may be regarded as a 

 composite plant — a plant whose roots are proof against 

 the attacks of the insect, and whose fruit produces a 

 wine which still maintains the local tradition. 



Diseases due to the attacks of fungi have also caused enormous losses to vine-growers. 

 The most important is undoubtedly that caused by Oidium (Erysiphe) Tuckeri. The disease 

 was first noticed in England near Margate in 1845, and in less than seven years it had spread 

 through all the wine-producing countries of Europe. The fungus appears on the surface of 



PHYLLOXERA. WINGLESS 

 FEMALE AND EGGS 



EGGS OF PHYLLOXERA 





