Death to the Rodents. 



423 



chard trees from depredations of pine mice from 1915 to 

 1917 were estimated at not less than $200,000. Similarly 

 heavy losses were disclosed in other States as attention was 

 directed to these direct causes of decreased production. It is 

 estimated that native rodents cause a loss of $150,000,000 a 

 year in the United States in cultivated crops and a similar 

 loss in forage on the pasture ranges, making a total loss of 

 $300,000,000 a year from this source. 



B20742; B20743 



Effect <>f Prairie Dogs on Range Production, 



Upper view, an area which has not yet been invaded by prairie dogs, showing 

 the natural stand of grama grass, one of the most valuable range forage plants. 

 Lower view, from photograph taken at the same time of a near-by area in- 

 vaded by prairie dogs. Here these pests have completely destroyed all valuable 

 forage grasses, reducing the stock-carrying capacity to zero. 



