GRAPE VINESVINE LOUSE. 



333 



Vine Louse (Phylloxera vastatrix). This pest forms galls on both roots and leaves of 

 varieties of the European vine (Vitis vinifera), and, if unmolested, soon destroys attacked 

 vines. The leaf injuries are trifling as compared witn those inflicted on the roots, to the 

 young rootlets of which the insects affix themselves and push their suckers (probosces) 

 through the bark. New cells are formed galls of varied size being developed, 

 some as large as a pea. These galls die, and the roots also, so that the vines are 

 starved, also further weakened by the insects abstracting food from the older roots 

 and leaves. The insect passes the winter on the roots. The effect is to ruin the vines 

 in two or three years, but the insects leave the vines for " fresh pastures" before 



B 



Fig. 106. VINE LOUSE ATTACKS ON ROOT AND LEAF. 



References : A, portion of vine-roots, showing swellings and galls ; a, hibernating larva (root form) ; 6, larva (leaf 

 form) ; c, wingless female ; d, winged female ; /, egg : this and insect forms greatly magnified. B, appearance of 

 attacks on leaf. 



their hosts are quite dead. The eggs are laid in autumn between the crevices of the 

 bark of the roots, and the larvse emerge in spring and pass into mature females with 

 little alteration beyond enlargement. The larvse generally attack the leaves, forming 

 small reddish warts on one surface of the leaf and a small depression on the other, 

 a slit, closed with hairs, forming the entrance to the gall. Wingless insects emerge 

 from the leaf-galls, form new galls, and ultimately pass down to the roots. 



The remedial means of destroying Phylloxera are various, and the most successful for 

 this country is to remove the vines and soil, thoroughly cleanse the house, then plant 

 vines free from nodosities at the extremities of the fibres, and in entirely new borders. 



