05 



healthy material to feed on. During the winter many of them remain torpid, and at that 

 season assume a dull brownish colour, so like that of the roots to which they are attached 

 that they are difficult to discover. They have then the appearance shown at 6 in figure 77. 

 With the renewal of growth in the spring, the young lice cast their coats, rapidly increase 

 in size, and appear as shown at e,J, 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 pro- 

 duced, 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 neighbouring vineyards, 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 individual root 

 lice abandon their underground habits and form galls on the leaves. 



The complete life history of this insect is very curious and interesting, but would 

 occupy too much space to fully detail here. Those desirous of pursuing this portion of 

 the subject further, and of informing themselves as to the different modifications of form 

 assumed by this insect in the course of its development will find the desired information 

 given with much minuteness of detail in the 5th, 6th, 7th and 8th Reports on the Insects 

 of Missouri, by C. Y. Riley. 



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. Flood- 

 ing 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 



Fig. 78. 



5 D.) 



