ECONOMIC VALUE OF OUR BIRDS 51 



particularly valuable species of spruce and pine has 

 its particular curse, from the Engelmann spruce 

 bark-beetle of the far Northwest to the southern 

 pine-beetle of Georgia and Florida. The deadly 

 seven are as follows, and their areas of destruction 

 are indicated by their names: 



Western pine-beetle, 

 Montana pine-beetle, 

 Engelmann spruce-beetle, 

 Douglas fir-beetle, 

 Southern pine-beetle, 

 Black Hills beetle, 

 Eastern spruce-beetle. 



These species cover all the areas of coniferous 

 forests in the United States. 



Corn. Of the cereal crops, corn is destroyed, 

 root, stem, leaves and fruit, by the following 

 insects : chinch-bug, corn- root worm, bill-bug, wire- 

 worm, boll-worm or ear-worm, cutworm, army- 

 worm, stalk-worm, grasshopper and plant-lice, in 

 all about fifty important species. Of all the cereal 

 crops, Wheat is the one that suffers most severely 

 from insects. Its three deadliest enemies are the 

 chinch-bug, Hessian fly and plant-louse. In the 

 year 1900, the Hessian fly caused, in the states of 

 Ohio and Indiana alone, the loss of 2,577,000 acres 

 of wheat ! 



The Hay and Forage crops are attacked by 

 locusts, grasshoppers, army-worms, cutworms, web- 



