LARGER CORN STALK-BORER. 3 
riddling the more tender leaves with aimless burrows. If the bur- 
row reaches the tender terminal bud where the future joints are 
being formed, further growth at that point ceases and the plant be- 
comes stunted and misshapen, with no tassel. As the plant continues 
to mature, the larva “grows out,” as the farmers say. It is more 
likely that it is not the larva itself but the evidences of its work 
that ‘‘grow out’’; but for whatever reason, the caterpillar soon leaves 
the more leafy portion of the plant and attacks the stalk at or near 
the ground. Here a hole is cut through the outer wall of the stalk 
Fie. 2.—Work of larger corn stalk-borer, showing mutilation of leaves of corn by larve. Greatly reduced. 
(Author’s illustration. ) 
and the larva burrows upward for a short distance, after which it 
seems to run aimlessly through the pith, frequently even leaving the 
stalk entirely and reentering it at another point. Turning upward, 
the caterpillar, when fully grown, bores toward the outsideand 
cuts a circular hole in the outer wall of the stalk. Then, after 
spinning a few loose threads across this opening to keep cut unde- 
sirable visitors, it retreats a short distance, plugs the burrow below 
with digested pith, and in the chamber thus created slowly changes 
to the next or pupal stage (fig. 4, ¢). 
