8 Farmers’ Bulletin 1294, 
others feed on the surface of the tassel buds and protect them-' 
selves with a slight silken web. 
As the tassel develops and the feeding borers become larger, they 
tunnel within the tassel] stalk and its branches. This injury so 
weakens the tassel stalk that it frequently breaks over. Such broken 
tassels (Fig. 4), with extrusions of frass or sawdust-like material at 
the breaks, are the most conspicuous signs of infestation in fields 
of growing corn. Field ccunts made in badly infested cornfields 
have shown as high as 80 per cent of such broken tassels. Certain 
corn plants, especially when attacked during an advanced stage of 
their growth, do not always exhibit this particular type of injury. 
Fic, 6.—Portion of cornstalk showing external evidence of 
the work of the European corn borer, (Caffrey.) 
After working in the tassel stem, the borers may continue tun- 
neling downward into the main stalk (Fig. 5), or they may leave 
the upper part of the plant and enter it, or neighboring plants, at 
points lower down (Fig. 5), gradually increasing the size of their 
tunnels as they develop, and working upward or downward, accord- 
ing to their individual preferences. Small holes in the plant with 
sawdust-like extrusions fig. 6) indicate where the borer is at work. 
Instead of feeding upon or within the tassel buds and tassel 
stalks, some of the newly hatched borers habitually migrate to points 
lower down on the plant. Under these circumstances they may enter 
