55 



Injuries to Corn. — With the exception of the southern species men- 

 tioned above, the injuries to corn are done entirely by the beetles, and 

 are commonly limited to the first year after grass. In some cases where 

 freshly drained swampy tracts have been broken up, the injury may 

 continue in diminished quantity the second year, provided that the crop 

 has not been sufficiently well tilled to kill out thoroughly all the coarse 

 native sedges and grass-like plants. The adults of all the species feed in 

 substantially the same manner, as far as observed, and inflict a similar 

 injury on the plants they infest. Placing itself head downward, with 

 its stout legs embracing and firmly grasping the stalk, the beetle applies 

 the tip of its beak straight against the surface, cutting the outer tissue 

 with the jaws, the action of which is distinctly audible. Gradually, with 

 an occasional twisting motion of the head, it sinks two thirds or more of 

 its snout into the stalk, and then, slightly rolling its head from side to 

 side with clocklike regularity, it uses its beak as a lever to split the stalk 

 and pry the edges of the slit apart. It pauses from time to time to eat 

 out the soft tissues within, and by moving forward and backward and 

 twisting to the right and left, it hollows out an interior cavity much 

 larger than the surface injury would indicate. Then, pulling the head 

 strongly backward with the compressed beak inserted, the stalk is split 

 upward as a boy would split a stick with a knife. In this way a slit an 

 inch long may be made in the stalk of corn, beneath which all the softer 

 parts have been eaten out. 



The injury thus done varies in position from a little below the surface 

 of the ground to the middle or upper two thirds of the larger leaves. 

 The beetles are often seen at work on young stalks, head downward, 

 with the beak inserted its full length. They are always on the lower part 

 of the plant, from an inch above the ground to a little be'ow it, and two 

 or three of them are sometimes seen on a single stalk. They are not 

 easily alarmed when thus engaged, and a plant may even be cut away 

 if care is used, without disturbing them. Although they cling closely 

 to it, they can readily be picked off with the fingers, and when thus 

 detached they do not seek to escape, but feign death for a little time. 



The effect on the corn plant of such injuries varies according to the 

 size and number of the beetles. A small species like the abundant 

 parvulus (Fig. 27) may do little more than to leave a trace of its visit in 

 the form of a series or two of oblong parallel holes across one of the 

 leaves; but the larger species, especially if several beetles attack the 

 same plant, may so rag and deform the young leaves that no ear is 

 matured, or may kill the plant outright. 



While there is in Illinois a little general and unclassifiable injury to 

 corn by the bill-bugs, by far the greater part of it occurs under one of 

 three conditions. If swamp lands are broken up from grass in spring 

 and planted to corn the same year, and especially if the common reed 



