[Y WOl 



203 



Rotation 



beetles hibernating in winter in the soil of the fields. One genera- 

 tion is produced annually. 



Control. Practice spring plowing and cultivation, 

 of crops and clean cultivation are advised. 



The Western Corn Root Worm. This worm or grub (Dia- 

 brotica longicornis Say) is two- 

 fifths of an inch long. It is 

 slender, and is whitish or 

 yellowish, with a black or 

 brown head. It produces a 

 small, greenish beetle one- 

 fourth of an inch long (Fig. 2 19). 



Life History. The beetle 

 lays its eggs in the soil of corn 

 fields in the fall and then dies. 

 The winter is passed in the 

 egg stage, the eggs hatching 

 after corn is planted hi the 

 spring. After that time until 

 fall the grubs are found at the 

 roots of the corn. The beetles, 

 in late summer and until cold 

 weather appears, are found on 

 or about the silk of corn and 

 on late summer flowers, such 

 as thistles, golden-rod, and red 

 clover. They disappear at once 

 on the advent of cold weather. 



Injury. By mining hi the 

 main roots of the corn, the 

 worm checks the plant's 

 growth and may cause its 

 death. 



Control. Practice crop ro- 

 tation. Corn planted the year 

 following another kind of crop 

 will not be injured. 



The Army Worm. The full-grown caterpillar of this species 

 (Heliophila unipunda Haw.) is nearly two inches long. It is 

 either of a dark gray or dingy black color. It has three narrow, 

 yellowish stripes above and a smaller, darker one at each side. 



FIG. 218. The sugar-cane beetle. (U. S. 

 Bu. Ent.) 



