II S E 0,5 PEST SU 2V U Y 3 
Vol. 22 Supplement to Ho. 3 
ESTHETES 0E DAMAGE TO COBIT 3Y THE EUROPEAN COM SOPER IIP 1941 
By A. 'M. Yance, Entomologist 
Divisio n o f Cereal and F orage Insect Investigations 
Burea,u of Entomology and Plant Quarantin e 
United States De part ment of Agricu l ture 
It is estimated that the loss from damage by the European corn borer 
( Fyrausta n ubllalis (Hbn. )) in 1S41 to the corn crop qoroduced in 258 counties 
surveyed within 18 of the infested northeastern States, and valued at approx- 
imately $270,000,000, was nearly $5,000,000. This estimate includes only the 
258 counties surveyed of the 555 counties known to be infested in the United 
States. It wa.s reached by the same procedure used in the preparation of simi- 
lar estimates in previous years, as follows; (l) Established-damage indices 
of 3-, 5-, and 3-percent loss per borer per plant to corn for grain, canning 
sweet corn, and| market sweet corn, respectively, were applied to populations 
of the insect found in each county surveyed in the fall of 1941 to obtain 
percentages of less in the types of corn represented. (2) Values of the 
corn crop in each county were estimated, and the money damage caused by the 
borer was calculated by applying to them the estimated percentages of loss. 
To obta.in these values, data on corn production and current market prices 
were procured from the 16th Agricultural Census (1940), from reports of the 
Agricultural Marketing Service of the United States Department of Agriculture, 
and from various State and citjzr organizations which generously supplied 
needed information. The 1941 quotations used for corn harvested for grain 
were preliminary. In the case of sweet corn, an effort was made to evaluate 
the crop on the basis of the proportion used for market and canning purposes, 
in the various counties surveyed within named States* and for this reason 
sweet corn crop values and losses in 1941 are no f ckr^ck.y comparable with 
previous estimates, (3) The county data were ocm'o: nek to show the money loss 
of corn for grain and of sweet corn for each State and for the surveyed area 
as a whole. 
In table 1 are presented the data on the value of the corn crop and the 
losses caused by the European corn borer in 1941 within the counties surveyed 
in each and all of the 18 States. These damage estimates wore prepared on the 
basis of 7,514,174 a.cres of corn harvested for grain, with an estimated crop 
value of $257,805,954, and 168,846 acres of sweet corn, with an estimated crop 
value of $12,405,200. The combined acreage of grain and sweet corn was 
7,683,020, and the estimated crop value of both totaled $270,211,154, The 
estimated total loss caused by the European corn borer to the corn crop in the 
area surveyed in 1941 was $4,935,990. Of this amount, 86.3 percent, or 
$4,260,248, occurred in corn harvested for grain, and 13.7 percent, or $675,742, 
in sweet corn. 
uBV ^ Y board 
t 1 Fi-AKT 
June 1, 1942 
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