ATTACKING THE ROOTS. 237 



these eggs hatch, and the young ones shortly become egg-laying 

 mothers like the first, and, like them, also remain wingless. 

 After several generations of these egg-bearing lice have been 

 produced, a number of individuals about the middle of sum- 

 mer acquire wings. These also are all females, and they 

 issue from the ground, and, rising in the air, fly, or are carried 

 with the wind, to neighboring vineyards, where they deposit 

 eggs on the under side of the leaves among their downy 

 hairs, beneath the loosened bark of the branches and trunk, 

 or in crevices of the ground about the base of the vine. 

 Occasionally individual root-lice abandon their underground 

 habits and form galls on the leaves. 



The complete life-history of this insect is extremely inter- 

 esting and curious, and those desiring further information as 

 to the different modifications of form assumed by the insect in 

 the course of its development will find it given with much 

 minuteness of detail in the fifth, sixth, seventh, and eighth 

 " Reports on the Insects of Missouri/ 7 by C. V. Hi ley. 



Remedies. This is an extremely difficult insect to subdue, 

 and various means for the purpose have been suggested, none 

 of which appear to be entirely satisfactory. Flooding the 

 vineyards, where practicable, seems to be more successful than 

 any other measure, but the submergence must be total and 

 prolonged to the extent of from twenty-five to 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 stated by some to be an efficient 

 remedy ; it is introduced into the soil by means of an auger 

 with a hollow shank, into which this liquid is poured ; several 

 holes are made about each vine, and two or three ounces are 

 poured into each hole. Being extremely offensive in odor 

 and very volatile, its vapor permeates the soil in every direc- 

 tion, and is said to kill the lice without injuring the vines. 

 This substance should be handled with caution, as its vapor 

 is very inflammable and explosive. Alkaline sulpho-carbon- 



