34 USEFUL BIRDS. 



for fourteen years following the civil war was estimated at 

 fifteen million dollars per year.^ 



In 1873 the injury to the cotton crop reached twenty-five 

 million dollars, and later averaged from twenty-five million 

 to fifty million dollars annually.^ Now a new enemy, the 

 Mexican cotton boll weevil (Anthonomous grandis) , threatens 

 equal destruction. 



The Rocky Mountain locust {Melanoplus spretus) began 

 to destroy crops as soon as the country it inhabits was set- 

 tled, and is still injurious. From time to time its enormous 

 flights have traversed a great part of the Mississippi valley. 

 It reached a maximum of destructiveness from 1874 to 1877, 

 when the total loss fi-om its ravages in Kansas, Nebraska, 

 Iowa, Missouri, and neighboring States, including injury by 

 depression of business and general ruin, was estimated at 

 two hundred million dollars." 



In those years this devastating insect swept over the Missis- 

 sippi valley. "Wherever its vast flights alighted or its young 

 developed, they destroyed nearly all vegetation, ruining 

 great numbers of farmers, causing a famine in the land, and 

 driving many people to emigration. This was an extreme 

 calamity, such as is not likely to occur again. 



A still larger but more widely distributed loss from insect 

 pests, however, is still borne annually by the American 

 people. Dr. Lintner states his belief that the annual and 

 periodical injury caused by cutworms in the United States 

 is greater than that caused by the Eocky Mountain locust. 



In September, 1868, Prof. D. B. Walsh, editor of the 

 American Entomologist, estimated that the country then 

 suffered to the amount of three hundred million dollars 

 annually from the depredations of noxious insects. By the 

 census of 1875 the agricultural products of this country were 

 valued at two billion, five hundred million dollars. Of this 



' Fourth Report of the United States Entomological Commission, hy C. V. 

 Riley, 1885, p. 3. 



^ Report on the Rooky Mountain Locust, by A. S. Packard. Ninth Annual 

 Report of the United States Geological and Geographical Survey of the Terri- 

 tories, 1875, p. 591. 



s Report on the Rocky Mountain Locust, by Riley, Packard, and Thomas. 

 First Report of the United States Entomological Commission, 1877, pp. 115-122. 



