GRAPE PESTS AND THEIR CONTROL 



207 



Fig. 37. The grape 

 root-worm. 



r. 



Fig. 38. Root- 

 worm beetle. 



void of rootlets and bark channeled by the pest. vSo plain 

 is the work of the root-worm that the grower never need be 

 at a loss as to the cause of vines injured by 

 this pest. The ^^\)rms feed during the latter 

 part of the growing season, reaching full growth 

 at this time. The next June 

 they transform intopupse and in 

 late June or early July emerge 

 as adult beetles. 



The presence of the adult bee- 

 tles is more easily detected on the foliage than is 

 that of the larvse on the roots, for the feeding 

 beetles ravenously devour the upper sides of the 

 leaves, leaving chain-like markings, shown in 

 Fig. 39, their destructiveness decreasing some- 

 what after a few days 

 from their first appear- 

 ance. A fortnight after 

 the beetles begin their 

 attack on the foliage the 

 female begins laying 

 her eggs, to the number 

 of 200, placing them 

 under the rough bark 

 of trunk and cane. 

 These hatch in late 

 July or August and 

 the young grubs at 

 once seek the roots. 



Two methods of con- 

 trol have been devised : 

 destruction of the bee- 

 tles before the\' la\' _ , . . , . , , 



, . ' " Fig. 39. Injuries caused by beetles oi the 



their eggs; and de- grape root-worm. 



