146 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



about one-fortieth inch long. The eggs are laid singly just beneath 

 the surface of the soil and hatch in from seven to ten days, those 

 laid early in the season requiring considerably longer. The 

 larvae become full grown and pupate about a month later, the 

 adult beetles of the first generation appearing during May and 

 early June in the Gulf States and in late June and early July in the 

 District of Columbia and Kentucky. Thus the complete life cycle 

 requires from six to nine weeks in the spring. Eggs are laid by the 

 first generation of beetles, the Iarva3 being found on the roots of 

 corn from midsummer until fall, when the second generation of 

 beetles is found in October and November in Kentucky. In the 

 Gulf States there are undoubtedly three complete generations, 

 though they have not been carefully followed.* The beetles 

 assemble in the late fall on clover and alfalfa upon which they feed 

 until winter sets in, and often come out and feed during warm 

 spells in January and February in the Southern States. 



Control. Although rotation of crops will not be as effective in 

 the control of this species as in the case of D. longicornis, it will 

 undoubtedly be found of value to avoid planting corn in succession 

 where injury is probable. By planting late, after the beetles have 

 laid their eggs, injury has been avoided in Georgia. Liberal seed- 

 ing, using ten grains of seed per hill, will give a sufficient stand 

 free from attack, so that by thinning a good stand may be secured. 

 Fields which are well infested with Johnson grass, or other thick- 

 stemmed grasses, should be avoided, for as already indicated the 

 beetles will be attracted to them before the corn is up. Both 

 on account of the feeding habits of the larvae and the migratory 

 habits of the beetles no insecticide treatment commends itself as 

 practicable. 



The Corn-root Webworm f 



Injury. When young corn-plants are seen to stop growing, 

 become deformed, and to die off in such numbers as to frequently 

 necessitate replanting, upon examination of the roots the injury 

 will sometimes be found to be due to the work of a small caterpillar. 

 Two or three, very often five or six, and sometimes as many as 



* In the Northern States, where this species is not a pest of corn, but is 

 common on cucurbs and garden plants, there is probably but a single genera- 

 tion with a life history very similar to that of the striped cucumber-beetle, 

 which see. 



f Crambus caliginosellus Clem. Family Crambidce. 



