The European Corn Borer. 31 
be easily confused with the European corn borer. The larger corn 
stalk-borer, however, does not bore into the ears of corn, whereas 
this habit is characteristic of the corn borer. This southern pest 
habitually overwinters only in the rootstock of the corn, whereas 
the corn borer not only winters in the stubble of corn, but may also 
be found in the stalks and ears of corn and in the stubble and stems 
of many other plants previously mentioned as hosts. 
The caterpillars of the larger corn stalk-borer are of two types— 
a summer form and a winter form. The summer form, when full 
Fic. 24.—The larger corn stalk-borer. Natural size. 
grown, is about 1 inch in length, with a dirty white body thickly 
dotted with round or irregularly shaped darkly colored spots. 
Each of these spots bears a short, dark bristle. The head region is 
brownish yellow. The winter form differs from the summer form 
in that the caterpillar is more robust and is slightly shorter, while 
the spots referred to above are nearly the same color as the body. 
In the Gulf strip and on the Mexican border two distinet but very 
similar and closely related caterpillars *° may attaek corn. 
3 Diatraea saecharalis Fab, and Diatraea lineolata Walker. 
