126 THE CANADIAN ENTOMOLOGIST. 



During the winter many of them remain torpid, and at that season assume 

 a dull brownish color, so like that of the roots to which they are attached, 

 that they are difficult to discover. They have then the appearance shown 

 at b in figure i6. With the renewal of growth in the spring, the young 

 lice cast their coats, rapidly increase in size, and appear as shown at e, /, g, 

 in the figure ; soon they begin to deposit eggs, these eggs hatch, and the 

 young shortly become also 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 summer 

 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 vine- 

 yards, where they deposit eggs on the underside 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 indi- 

 vidual root lice abandon their underground habits and form galls on the 

 leaves. 



The complete life history of this insect is extremely interesting and 

 curious, and those desirous of further information as to the different modi- 

 fications of form assumed by the insect m the course of its development, 

 will find them given with much minuteness of detail in the 5th, 6th, 7th 

 and 8th Reports on the Insects of Missouri, by C. V. Riley. 



Remedies : This is an extremely difticult 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 claimed by some to be an efficient remedy ; 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 vapor permeates the soil in every 

 direction, 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. 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 



