G MONTANA EXPERIMENT STATION Bui. 13it 



greater part of Montana owing to the serious damage which it has 

 inflicted upon cereals and other crops. The following table of losses 

 by percentages of total seeded areas in the various counties for 

 which we had definite information during the season of 1920 will 

 nidicate the seriousness of this pest : 



Hill County 25.1 per cent ■ 



Liberty County -17.1 



Cascade County 35. 



Jefferson County 3G.()1 



Broadwater County 23.9 



Chouteau County. 30. T " " 



Phillips County 16.9 " " 



Teton County 29. " " 



A\'erage 30.4 " " 



When the counties of Pondera, Glacier. lUaine, Juditli I'asin, 

 Lewis and Clark, and part of Park Cnuntv, where it is estimated 

 almost as large a percentage was lost, are included with the above 

 counties, fully one-fourth of the total grain-producing acreage of 

 the state is represented. At $12 per acre, which is the aA'erage A'alue 

 (f farm crops over that territorv, there was a monev loss of 

 $2.0(10.000. Then, considering that the pale western cutworm 

 (.ccurs in practically every other county of the state east of the 

 Continental divide besides those already mentioned, where an a\'erage 

 loss of from 2 per cent to 5 per cent w^as inflicted, the total loss 

 amounts to well above $3,000,000 for the one year 1920. 



To show perhaps a little more clearly what this cutworm has 

 l)een doing, one hundred fields personally inspected during the sum- 

 mer showed a loss of 2,437 acres out of a total of 6,844 in 1919, and 

 in 1920 a loss of 3,382 acres out of 6,844, or 35.7 per cent in 1919 

 and 49.4 per cent in 1920. Mr. George O. Sanford, manager of the 

 Sun River Irrigation Project, has stated to us that of the 15,300 

 acres seeded to crop on the Greenfield P)ench in 1920, 7,345 acres 

 was a total loss and that some damage was done to the remainder. 

 Using the figures he has gi\-en for the average yields on the unde- 

 stroyed acreage — wheat 11.5 I^ushels, oats 20.86 bushels, and flax 

 6.31 bushels — the average value r)f the principal farm crops of that 

 section was at least $15 per acre. Accordingly, using that as a fair 

 \'aluation per acre of the crops destroyed, the pale western cutworm 



