66 



thirty days ; it should be undertaken in September or October, when it is said that the 

 root lice will be drowned, and the vines come out uninjured. 



Bisulphide of carbon is claimed by some to be an efficient remedy j it is introduced 

 into the soil by means of an augur with a hollow shank, into which this liquid is poured ; 

 several holes are made about each vine, and two or three ounces of the liquid poured into 

 each hole. Being extremely offensive in odor and very volatile, its vapour penetrates the 

 soil in every direction, and is said to kill the lice without injuring the vines. This sub- 

 stance should be handled with caution, as its vapour is very inflammable and explosive. 

 Carbolic acid mixed with water, in the proportion of one part of acid to fifty or one 

 hundred parts of water, has also been used with advantage, poured into two or three 

 holes made around the base of each vine with an iron bar to the depth of a foot or more. 

 Soot is also recommended, to be strewed around the vines. 



It is stated that the insect is less injurious to vines grown on sandy soil ; also to 

 those grown on lands impregnated with salt. 



Since large numbers of these insects, both winged and wingless, are known to crawl 

 over the surface of the ground in August and September, it has been suggested to 

 sprinkle the ground about the vines at this period with quicklime, ashes, sulphur, salt or 

 other substances destructive to insect life. The application of fertilizers rich in potash 

 and ammonia have been found useful, such as ashes mixed with stable manure or sal- 

 ammoniac. 



A simple remedy for the gall-inhabiting type is to pluck the leaves as soon as they 

 show signs of the galls, and destroy them. 



Several species of predaceous insects prey on this louse. A black species of Thrips 

 with white fringed wings deposits its eggs within the gall, which, when hatched, produce 

 larvae of a blood red colour, which play sad havoc among the lice. The larva of a 

 Syrphus fly, Pipiza radicum, which feeds on the root louse of the apple, see figure 79, 

 has also been found attacking the Phylloxera. Another useful friend is a small mite, 

 Tyroglyphus phylloxera, P. & R, see (Fig. 80), which attacks and destroys the lice, and 



Fig. 80. 



associated with this is sometimes found another species, Holophora arctata, Riley, of a 

 very curious form, reminding one of a mussel. In (Fig. 81), this minute friend is repre- 

 sented highly magnified in the different forms assumed by it. 



These lice are also preyed on by 

 the larvae of a Scymnus, a small dull 

 coloured lady bird ; also by several 

 other species of the lady-bird family, 

 and by the larvae of lace-wing flies. 



To guard against its introduction 

 into new vineyards, the roots of young 

 vines should be carefully examinee 1 



Fig. 81. 



before planting, and if knots and lice 



are found upon them, these latter may be destroyed by immersing the roots in hot soap 

 suds or tobacco water. 



Our native American vines are found to withstand the attacks of this insect much 

 better than do those of European origin, hence by grafting the more susceptible varieties 



