14 UNIVERSITY OP CALIFORNIA EXPERIMENT STATION. 



strips are usually eaten out in a direction parallel with the axis of the 

 root, or in a spiral direction. The "frass" or eaten bark is left in their 

 paths and is characteristic of their injury. The furrows made are from 

 one tenth to one fifth of an inch wide, and in cases of severe injury 

 all the bark may be eaten away from the roots. 



This feeding is continued from the time they hatch in the spring 

 until the vine becomes dormant in the fall. By September 1st some 

 of the larvae were found nearly full grown, while others were not more 



FIG. 10. Grape leaf showing characteristic work of the beetle. 



than half grown. In the case of the latter, their growth is completed 

 by feeding during the following spring, which accounts for some of the 

 larvae being found as late as the last of May. The first observed appear- 

 ance of the young larvae in the Lodi section in 1907 was on May 30th, 

 this being about a month after the first appearance of the beetles. 



The larvae were found as far down as two and a half feet, and no 

 doubt go farther than this, since in some of the vines there were no 

 roots to speak of nearer than a couple of feet from the surface. The 

 larvae were found within a radius of fifteen inches from the main central 

 root, and no doubt the majority occur within a radius of a couple of 



