INSECT PEST SURVEY BULLETIN 
Vol. 20 
Supplement to No. 9 
December JO, 1940 
ESTIMATES OE DAMAGE BY THE EUROPEAN CORN BORER IN 1940 
* * . * 
By A. M. Vance, Entomologist' 
Division of Cereal and Forage Insect Investigations , 
Bureau of Entomology and. Plant Quarantine , 
United States Department of Agriculture . 
The European corn borer ( Pyrausta nubilalis Hbn.) in 1940 caused an esti- 
mated loss of slightly more than $' 6 , 500,000 to the corn crop produced in 2’58 
counties of the Northeastern States and valued at approximately $126,000,000. 
In 1939^ damage by the insect to corn valued at approximately $106,000,000 an< 
grown over a slightly larger and not entirely comparable area in the same part 
of the country was estimated at almost $4,000,000, It is believed that these 
estimates provide a, fairly reliable and conservative picture of the current 
economic importance of the pest. 
The damage estimates in 1940 were calculated in the same way as in previo 
years. The percentage of loss of yield was determined by applying the estab- 
lished damage indices of 3 percent and S percent loss per borer per plant for 
field and sweet corn, respectively, to the da.ta, on county abundance of the cor: 
borer obtained in the fall of 1940.^/ Da.ta on corn production were taken from 
the 1935 Agricultural Census and' seasonal market Quotations on corn were con- 
tributed by the Agricultural Marketing Service of the United States Department 
of Agriculture in Washington and in the field, and by several State and city 
marketing agencies. In the calculations the 1940 quotations for corn ha.rv.es te* 
for grain are preliminary and the prices of sweet corn are averages of daily 
quotations for the crop-marketing season. The following prices for 1940 were 
used: 
Corn harvested for grain, cents per bushel: West Virginia, SO; New Jcrs 
and Pennsylvania, 7^» Connecticut, Rhode island, and Virginia, 77 » New York, 7 
Massachusetts and Vermont, 73 * Kentucky, Maine, and New Hampshire, ~J2‘, Marylai: 
70; Delaware, 6S; Ohio, 66; Michigan, 65 ; Illinois and Indiana, 62 ; and Wiscon* 
sin, 60 , 
Sweet corn, cents per dozen ears} Connecticut, 21; New Jersey, IS; wostc 
New York, 1J; Maine, Massachusetts, New Hampshire, eastern Now York, Ohio, 
Pennsylvania, Rhode Island, Vermont, and West Virginia., 15? Delaware, Maryland 
and Virginia, l4; Michigan, 13; Illinois, Indiana., Kentucky, and Wisconsin, 12. 
See Insect Pest Survey Bui. v, 19, sup. to No. 1, March 15,19^0, 
See Insect Pest Survey Bui. v, 20, sup. to No. 9* December 20, 1940. 
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library 
STATE PLANT BOARD 
