ROUGH-HEADED CORN STALK-BEETLE. 



zc:^ 



Fig. fi. — The rough- 

 lioaded corn stalk- 

 beetle : I'upa. Eu- 

 larged. 



I 



The pupa (fig. 8) is about three-fourths of an inch long by three- 

 eighths of an inch broad. When it first becomes a pupa it is white 

 but gradually changes to pale brown. During this stage the insect 

 does not feed and is incapable of locomotion and 

 remains throughout its existence in one place in 

 the soil, anywhere from an inch to several inches 

 below the surface. In this stage the insect is de- 

 stroyed easily by cultivating the soil and expos- 

 ing the pupae to the sun and the attacks of birds, 

 poultry, or hogs. 



THE ADULT. 



The beetle (see title page and fig. 1) develops 

 within the pupa and when fully formed ruptures 

 the old pupal skin and crawls forth. At first it 

 is almost wdiite, but gradually changes to an in- 

 tense black. The majority of the beetles emerge 

 during the month of September. 



During the fall the beetles spend most of their 

 time in the ground, but on warm days come to 

 the surface to feed. At this time they do not molest corn, but sub- 

 sist on certain wild grasses which grow^ abundantly in old pastures 

 and waste areas. With the advent of cold weather the beetles pass 

 into a condition of torpor called hibernation, during which they re- 

 main inactive in the ground. With the reappearance of warm 

 weather in late April or early May they become active once more. 

 If food be present, the beetles in most instances remain near the 

 place where they had passed the winter, but when this is lacking 

 they come to the surface and crawl or fly away in search of a more 

 ])romising spot. About this time the young corn is beginning to 

 appear above ground and the beetles, which either have passed the 

 winter in the field itself or perhaps merely wandered into it from 

 some other field where food was scarce, soon discover and attack the 

 young plants. xVs the season progresses and the temperature rises the 

 beetles become more active and their appetites are correspondingly 

 more difficult to satisfy. Mating takes place below the surface of 

 the ground and the eggs are laid shortly after. Thus the life cycle 

 starts once more. The old beetles continue active until about the 

 middle of June, after which they disappear quickly. 



CONDITIONS FAVORABLE TO OUTBREAKS. 



The natural home of the rough-headed corn stalk-beetle consists of 

 low, poorly drained open fields which have not been cultivated for a 



