196 INSECTS INJURIOUS TO VEGETABLES 



crop. A year or two after the first attack, the beetles usually 

 disappear, since only a few species live in the larval stage on 

 corn. The larvae feed at the roots and in bulbs of the forms 

 of vegetation that have been mentioned, which include nut-grass 

 and various true grasses such as timothy. The greatest injury 

 is due to the perforation of stalks of corn just at or below the 

 surface when plants are only two or three inches high. The 

 beetles sink their beaks deeply through the unfolded blades so 

 that when these unroll little rows of both round and elongate 

 longitudinal holes are left as evidence of earlier attack. As with 

 injury by root-worms and some other insects which live in more 

 or less concealment at or below the soil surface, close scrutiny 

 is necessary in order to detect bill-bugs, and damage which is 

 usually first manifested by the wilting and dying of plants and 

 their stunted growth is apt to be attributed to other causes. 

 The habits of these insects, in common with other snout-beetles 

 when disturbed, of drawing their antennae and legs closely to 

 their bodies, and of their bodies being frequently more or less 

 covered with dirt, are of assistance in their concealment. A 

 common injurious form is shown in figure 124. 



The Southern Corn Bill-bug {Sphenophorus maidis Chittn.) 

 is one of the most pernicious bill-bugs, and a good example of 

 a species that lives in its larval as well as adult stage on corn. 

 It is most destructive in lowlands and occurs in the Gulf region 

 and in Kansas. Of the habits of this species Dr. L. O. Howard 

 says substantially : 



"Wherever the larva had reached full size, the pith of the 

 stalk was completely eaten out for at least five inches. Below 

 ground, even the hard, external portions of the stalk were 

 eaten through, and in one instance everything except the root- 

 lets had disappeared, and the stalk had fallen to the ground. In 

 a great majority of instances a single larva was found in a 

 stalk, but in a few cases two larvae were at work. In no case 

 had an ear filled on a stalk bored by this larva. The stalk 



