254 



INJURIOUS INSECTS 



with age. From the time it is one-third grown, the 

 little dusky wing-pads may be discovered, though less 

 conspicuous than in the pupa state, which is soon after 



Fig. 155. GRAPE PHYLLOXERA, ROOT-INHABITING TYPE. 



a, Shows a healthy root ; 6, one on which the lice are working, representing the 

 knots and swellings caused by their punctures ; c, a Boot that has been de- 

 serted by them, and where the rootlets have commenced to decay ; 

 d, d, d, show how the lice are found on the larger roots ; f, fe- 

 male pupa, dorsal view ; /, same, ventral view ; fir, winged 

 female, dorsal view; h, same, ventral view. 



assumed. The pupae (fig. 155, e, /), are still more active, 

 and, after feeding a short time, they make their way to 

 the light of day, crawl over the ground and over the 

 vines, and finally shed their last skin and assume the 



