SB 
818 
C578 
ENT 
CIRCULAR No. 116. Issued February 7, 1910. 
United States Department of Agriculture, 
BUREAU OF ENTOMOLOGY, 
L. O. HOWARD, Entomologist and Chief of Bureau. 
THE LARGER CORN STALK-BORER.2 
(Diatrea saccharalis Fab.) 
By Grorce G. AINSLIE, 
Associate Professor of Entomology, Clemson Agricultural College of South 
Carolina. 
INTRODUCTION. 
In many southern cornfields a heavy wind late in the season, be- 
fore the corn is matured, does great damage by breaking the plants 
off at the surface of 
the ground, thus 
. . > 
ruining them. An 
examination of these 
broken stems will, in 
most cases, show that 
they have been 
greatly weakened by 
the burrows of a 
larva or caterpillar. 
This larva (fig. 1) is 
known as “the lar- 
ger corn stalk-borer ” 
(Diatrwa sacchara- Fic. 1.—The larger corn stalk-borer (Diatrea saccharalis) : 
lis). Its work is a, Summer form of larva; 6, c, hibernating forms of 
1: Eh 1] : itl : tl larve; d, third thoracic segment from above; e, eighth 
argely within ne abdominal segment from above; f, abdominal segment 
stem of the plant and from above; g, same from side. a, b, c, Enlarged; d, e, f, 
oi aN still more enlarged. (Redrawn from Howard.) 
is so concealed that, 
in most cases, unless weather conditions make it conspicuous, the 
presence of the insect passes unnoticed. 
1 
a 
oe 
a@This is practically a revision of Circular No. 16, prepared many years 
ago by Dr. L. O. Howard. Mr. Ainslie was formerly in the employ of this 
Bureau as an agent and expert in cereal and forage insect investigations, and 
this pest was one of the subjects of investigation assigned to him. He after- 
wards did some work upon the species for the South Carolina Agricultural 
Experiment Station in cooperation with this Bureau. , ..(30inu eISUTy ps 
21731—No. 116—10 a 4a, 
FEB 21 1950 
ig Zhe 
