WEB WORMS INJURING THE ROOTS 



113 



The worms feed in a silk tube more or less covered with par- 

 ticles of dirt. They vary in color from yellowish to brown, 

 are three fourths to one inch long when full grown, and their 

 bodies have numerous low tubercles. They hatch from eggs 

 laid by small, active moths which have the habit of resting on 



grass stems with their wings folded 

 around their bodies. The natural breed- 

 ing place is grassland. There are two 

 generations annually, the moths of the 

 second brood appearing in the latter 

 part of summer. Winter is passed by 

 the half-grown worms in the soil. 



Fig. 70. — Larval cu.se of Corn- 

 root Webworm at base of corn 

 plant. Original. 



Fig. 77. — Larval cases of a Corn-root 

 Webworm, Cramhus vulvivagellus Clem. 

 Natural size. The one at the left cut 

 open to show pupa within. Original. 



Fall plowing and cultivation will help to hold the pests in check, but 

 to avoid injury do not plant corn in land that is just broken up from sod. 

 Land that is fallowed in the latter part of summer will not be infested 

 the next spring, for the moths will not lay eggs on bare ground. 



The Corn Root Aphis {Aphis maidi-radicis Forbes) 

 Colonies of bluish green " lice " suck the juices from the roots of 

 corn, and in certain sections feed also on the roots of other plants, in- 



