74 



A similar study of the temperature records of these two sets of 

 counties shows that the mean temperature of the uninfested area for 

 June, July, and August, 1914, was 78.9 degrees F., and that of the 

 infested area was 79.5 degrees, the latter counties averaging only .6 

 of a degree warmer than the former — a difference much too small 

 to have any noticeable effect on the yield of crops. Evidently the 

 weather of the season could have given no advantage to the corn 

 crop of the uninfested counties. 



Thus satisfied that these two areas might be fairly compared and 

 that any marked difference shown by them in the yield of crops sub- 

 ject to chinch-bug injury must be due to the insects themselves, I 

 have compiled the reports of the 1914 corn crop, published by the 

 State Department of Agriculture in its crop report for December of 

 that year. From these I find that the average yield per acre in the 

 infested counties was 18.1 bushels and that in the uninfested coun- 

 ties it was 25.2 bushels, a difference of 7.1 bushels per acre which I 

 could attribute only to chinch-bug injury. The total area of corn 

 in the seventeen counties thus injuriously infested was, by the same 

 crop report, 947,582 acres, and the total loss of corn at the above 

 rate per acre was 6,727,432 bushels, which, at sixty cents a bushel, 

 the minimum current price of corn that fall, amounted to $4,036,699. 



This, however, is not all. The December report of the State De- 

 partment of Agriculture shows not only the quantity of the crop 

 but its quality as well, on a scale of ratios in which a fair average 

 quality is rated at 100 percent. Comparing the quality ratios of the 

 corn crop in our two sets of counties separately, I find that the corn 

 of the infested counties was graded at 60.8 percent of an average, 

 while that of the uninfested counties was 85.9 percent, a difference of 

 virtually a fourth in favor of the corn of the uninfested counties. We 

 shall have, therefore, to make a further reduction of fifteen cents a 

 bushel in the market value of the product of the infested counties, thus 

 increasing our loss of corn by a fourth, and bringing the total loss in 

 1914 for these seventeen counties up to $5,045,874. • 



Corn is but one of three important crops subject to destruction 

 by chinch-bugs, the others being wheat and oats. A similar use of 

 the crop reports to that above described gives a yield of wheat per 

 acre in 1914 of 19y 2 bushels in the uninfested counties and 16 bush- 

 els in the infested counties, a difference of 3y 2 bushels per acre at- 

 tributable to chinch-bug injury. The total acreage of wheat in the 

 infested counties was 516,589 acres, and the average price per bushel 

 August 1 was seventy-five cents. From these data we obtain a loss 

 of $1,356,039 in wheat due to chinch-bug injury. The loss in oats is 

 much less important. This crop in the infested counties occupied only 

 16,422 acres, with an average yield per acre of 6.1 bushels less than 

 that in the counties uninfested. An average price of forty-one cents 

 per bushel August 1 gives us a total loss of $41,071 for 1914. 



