506 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



When established on the roots they feed freely and grow rapidly, 

 becoming nearly full grown !)}' fall. In the fall they descend 

 several inches into the soil and make small earthen cells, in which 

 they hibernate. In the spring they return to the roots nearer 

 the surface, and those not already full grown feed until growth 

 is completed. They then make small earthen cells 2 or 3 inches 

 below the surface of the ground in which they transform to pupa). 

 These cells are easily broken open and the pupse are thus crushed 

 or killed by stirring the soil in cultivation. The pupa, shown 

 in Fig. 364, e, is one-quarter to one-third inch long, whitish, with 



FIG. 364. The tender pupa of the grape root-worm in its earthen cell, enlarged 

 natural size at n. (After Slingerland.) 



the head, thorax and tip of the abdomen pinkish, and with spines 

 on the head, appendages, and abdomen as illustrated. The pupa3 

 are most abundant in New York during June, the pupal stage 

 lasting about two weeks. 



Control. Extensive experiments made by several investigators 

 have shown that the beetles may be very largely destroyed by 

 thorough spraying with arsenate of lead just as they appear. 

 By applying the poison when they are first noticed feeding they 

 may be killed off before many of the eggs are laid, and sprayed 

 vineyards have shown a reduction of over 90 per cent of the eggs 

 found on untreated vines. Arsenate of lead should be applied at 



