The Bulletin. 



27 



they were present above where the ear Avoiild be. As a rule, it works in 

 the lower part of the stalk (especially later in the season) and often close 

 to the ground. In Mecklenburg County it was reported as having de- 

 stroyed a very serious per cent of the stalks in 1913. 



Life-history. — As an enemy of corn, studies of this pest have been 

 published by both Dr. L. O. Howard^ and George C. Ainslie- of Wash- 

 ington, and by Prof. R. I. Smith,-" formerly of the North Carolina 

 Station. Two distinct broods are recognized. The winter is passed in 

 the caterpillar stage below the ground level in the stalks or roots of 

 corn, perhaps also in some other plants. In spring the caterpillars 

 change to the pupa state, from which the adult moths emerge after about 

 two weeks. These moths then lay eggs on the young corn and these 

 hatch into the first destructive Avorms of the season, boring into the 

 stalks and tops of the growing corn, their injuries becoming noticeable 

 from June 10 to 20, at which time the worms are growing rapidly and 



r 



{ ■ 





Fig. 8. — Pupa and adult of larger Corn Stalk- 

 borer, a, adult moth, h, showing wings of 

 male moth, c, pupa. Natural size of moth 

 and pupa indicated by lines. 



(After Howard, Div. of Ent., U. S. Dept. Agr.) 



boring actively in the stalks. In Robeson County (1902) we found 

 grown worms and others that had changed to pupae on June 30th, and 

 from these we reared adult moths July 8th. The first brood of moths, 

 therefore, appeared that year to emerge first half of July, though two 

 years later we received larvae from Mecklenburg County on July 2d ; so 

 in the higher and cooler sections they are probably always somewhat 

 later in reaching maturity. The second brood of worms burrow into the 

 stalks chiefly in the first two joints above ground, and often so weaken 

 the^n that they are blown to the ground. The worms of this second gen- 

 eration become grown by harvest, burrow down the center of the stalks 



^f'ir. 16, second series, Div. l-^nt., V. S. Dept. As 

 Howard, Aug.. 1S9G. 



"Larger Corn Stalk-boror." L. O. 



-Cir. 116, second series. Uur. V.wX., V. S. Dept. Agr., ''Larger Corn Stalk-borer." George 

 N. Ainslie, Feb., 1910. 



"Bui. 107, N. C. Exp. Sta., "Insects of Garden Crops." R. I. Smith. May, 1008, p. .35. 



