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EUROPEAN CORN BORER 
( Pyrausta nubilalis (Hbn.)) 
Life History 
Although the European corn borer attacks many cultivated crops and 
weeds, it is discussed here mainly as an enemy of corn, its favorite host 
plant. The eggs are laid overlapping one another like fish scales, in 
masses of 15 to 20 or more on the under sides of the corn leaves, and hatch 
in 4 to 9 days. The tiny borers immediately crawl to protected places 
on the plants, where they feed on the tissues of the immature leaves and 
tassels, and eventually bore inside the stalks and into the ears. They 
become full grown in about a month and, after providing an exit for 
the adult moth, change to pupae inside the burrows, either at once or 
after an inactive period. In 10 to 14 days the adult moths emerge from 
the pupal cells and lay about 400 eggs each on corn or other plants that 
they may find in an attractive stage of growth. The moths live from 10 
to 24 days. They are active fliers during the evening or night and may 
migrate several miles. These insects pass the winter in the borer stage 
inside infested stems of corn or other plants, and here they change to 
moths late in the spring or early in the summer. There are one or more 
generations a year, depending on the length of the growing season in 
different latitudes. 
Control 
A. Destroy overwintering borers by disposing of infested cornstalks — 
1. By feeding to livestock direct or as silage or in finely cut or 
shredded form. 
2. By plowing under clean in the fall or in early spring before the 
moths emerge, using attachments such as trash shields, wires, or 
chains to insure burial of all stalks. 
3. By burning infested plants completely, where other methods of 
disposal cannot be used. 
B. Plant as late as practicable, but only within the normal planting 
period adapted to the locality. Moths of the first brood lay their 
eggs on the earliest planted corn. 
C. Plant resistant or tolerant kinds of hybrid corn. No immune strains 
are available, but hybrids differ in their resistance and tolerance. 
Select types that will mature when planted moderately late. Con- 
sult your county agent or your State experiment station on the best 
hybrids to plant in your locality. 
I >. Modify cropping practices. 
1. Avoid sowing fall wheat or other small grain in standing corn 
or corn stubble. Plow the cornstalks under clean or cut them 
at ground level and remove them before seeding small grain. 
2. Dispose of all early sweet cornstalks in fields and gardens im- 
mediately after harvesting the ears, by feeding, ensiling, or plow- 
ing them under. Dispose of cobs and other remnants from the 
cannery in the same manner. 
E. Use insecticides where profitable. Consult your county agent or 
State experiment station for current recommendations. 
Apply as many of the measures suggested above as may be practicable 
under local conditions. Community application of these methods is 
necessary for most effective control. Control of this insect is essential 
to the maximum production of corn so urgently needed for food and 
feed purposes. 
Reprinted by the Office for Food and Feed Conservation. 
April 1948 U. S. Government Printing Office 
For Sale by the Superintendent of Documents, Washington 2.1, 
I). C. Price, 5 cents. 
