PROGRESS REPORT ON THE EUROPEAN CORN BORER 
27 
eluding the base or stubble. During this tunneling operation large 
quantities of yellowish-white frass, mixed with silken strands spun 
» 
Fig. 8.- 
-Cornstalk, external view, showing extruded frass and entrance to burrow 
of larva of the European corn borer 
by the larva, are pushed out of the entrance hole and suspended 
there by the silken strands or collected below in the axils of the leaf 
blades. (Fig. 8.) These masses of frass are very conspicuous and 
