Httiupratty of fUinnfaota 
AGRICULTURAL EXTENSION DIVISION* 
Special Bulletin No. 8 
University Farm, St. Paul July 1916 
Published by the University of Minnesota, College of Agriculture, Extension Division, A. D. 
Wilson, Director, and distributed in furtherance of the purposes of the cooperative agricultural ex- 
tension work provided for in the Act of Congress of May 8, 1914. 
SOME INSECT ENEMIES OF CORN 
By Warren Williamson, Division of Economic Zoology 
' ' ♦ 
COMBATING INSECT ENEMIES 
The most important factors in the control of insect enemies of corn and other 
field crops are crop rotation, clean cultivation, and timely plowing. There are, of 
course, special cases which require special treatment, but we must rely principally 
on methods which can be carried on at small expense and which fit in with the 
ordinary farming operations. 
To combat them intelligently, the farmer should know insect pests when he 
sees them and have a practical knowledge of their habits and life history. Famil- 
iarity with scientific names and other technical details is not necessary, but, as one 
writer has said, the farmer should have a “business acquaintance” with the insects 
which attack his crops. 
SYNOPSIS OF INSECTS AND INJURIES 
Injuring Seed in Ground 
Wireworms. — Slender, hard, wiry, shiny, brown or yellowish six-legged larvae, 
about one inch long. They gnaw or bore through the kernels.. 
Seed-corn maggots. — White, footless larvae about one-fourth of an inch long. 
They bury themselves in the seed. 
Injuring Roots 
White grubs. — Large, fat, white worms, or larvae, with six legs, a large brown 
.head and stout jaws; body curved. They eat the roots of the corn. 
Corn root-lice. — Bluish green lice, about one-sixteenth of an inch long, found 
on the roots. Many small brown or yellowish ants usually are found with them in 
the hills. They cause the roots to wither or become dwarfed, but do not eat them. 
Corn root-worms. — Slender, white, six-legged larvae with brown head and 
neck and brown patch on the last segment. They burrow in the roots, and may be 
found by peeling or splitting the roots. 
Injuring Roots and Underground Part of Stalk 
Wireworms. — Previously described. They eat the roots or penetrate the 
stalk 
*State Entomologist’s Circular No. 39. 
