210 



ENTOMOLOGY. 



leaves and the other forming small swellings on the root- 

 lets. The root-form is both wingless and winged, the latter 



FIG. 256. The Phylloxera, root-form: a, healthy root; b, one in which the lice are 

 working, their punctures causing the swellings; c, a root deserted by them, the 

 rootlets beginning to decay; d, d, d, d, lice of natural size on the larger roots; 

 e, pupa of the female, g. After Riley. 



very rare; the leaf-form is said to be always wingless. The 

 chief injury is done to the roots, which die under the at- 

 tacks of this minute, insidious foe. 



All direct applications of chemicals, and the removal and 

 burning of the bark of the vines, usually result in failure to 

 kill the few winter eggs to be found; Riley maintaining 

 that the normal mode of hibernation of the species is as a 



