136 



PESTS OF GARDEN AND FIELD CROPS 



stalks of potato plants, frequently killing the vines. Its work is 

 evident usually in midsummer. The adult is a gray snout beetle, 

 with three black spots at the hind end of its thorax. It lays eggs 

 just under the surface of the vines, and the grubs work beyond 

 the reach of poison. Fortmiately, the adults remain in the stalks 

 over winter, and the pest is easily checked for the next season by 

 removing and destrr^ying the vines as soon as the crop of potatoes 

 is harvested. Neighboring weeds also should be destroyed. 



The Lima Bean Stem-borer {Monoptilota nuhilella Hulst) 



In a few sections in the South 

 the stalks of lima beans are at- 

 tacked by a borer, wliich bur- 

 rows inside and causes the for- 

 mation of characteristic galls. 

 The worm is bluish green, and 

 nearly an inch long when full 

 grown. There are probably two 

 generations in the southern 

 part of the insect's range. 



Winter is passed as larva or 

 pupa in the soil. Fall plowing 

 and cultivation will help to sup- 

 press the insect. If stems show- 

 ing the galls of the first genera- 

 tion are removed and destroyed, 

 the numbers of the second gen- 

 eration should be materially 

 reduced. 



The Hop-plant Borer ( Hydrce- 

 cia immanis Grt.) 



The hop-plant borer feeds at 

 three different points in or on 

 the vines in the course of its 



Fig. 123. — Work of 

 the Lima Bean 

 Stem-borer. Orig- 

 inal. 



Fig. 124. — Work 

 of the Hop-plant 

 Borer. Original. 



