136 PESTS OF GARDEN AND FIELD CROPS 
stalks of potato plants, 
evident usually in midsummer. 
frequently killing the vines. Its work is 
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. 
Fortunately, the adults remain in the stalks 
over winter, and the pest is easily checked for the next season by 
removing and destreying the vines as soon as the crop of potatoes 
is harvested. Neighboring weeds also should be destroyed. 
The Lima Bean Stem-borer (Vonoptilota nuhilella Hulst) 
Fic. 123.— Work of 
the Lima Bean 
Stem-borer. Orig- 
inal. 
In a few sections in the South 
the stalks of lima beans are at- 
tacked by a borer, which 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 ( Hydre- 
cia immanis Grt.) 
The hop-plant borer feeds at 
three different points in or on 
the vines in the course of its 
Fic. 124.— Work 
of the Hop-plant 
Borer. Original. 
