INSECTS INJURIOUS TO SMALL GRAINS 123 



and clover lands, to the number of three hundred each. Eggs 

 are laid for another brood in September, the maggots from which 

 live over winter. 



Remedies. Injury to wheat-land may be largely prevented 

 by plowing early in September. 



No satisfactory remedy for the maggots is known when 

 injuring clover, timothy, or grass, although large numbers have 

 been destroyed by driving a flock of sheep over infested 

 land. Dr. S. A. Forbes states that " close trampling of the 

 earth by the slow passage of a drove of pigs would doubtless 

 answer the same purpose, which is that of destroying the larva? 

 lying free upon the surface or barely embedded among the roots 

 of the grass." 



Several of our common birds as well as a number of ground- 

 beetles feed upon the maggots and flies. The maggots are 

 also sometimes attacked by a fungous disease which in the 

 damp soil in which they live doubtless grows and spreads 

 rapidly. Altogether these different enemies keep them so well 

 in check that they rarely become of importance. 



The Hessian Fly * 



The Hessian fly is much the most destructive of any of the 

 insects attacking wheat, to which its injury is practically con- 

 fined; 'for though it occasionally injures barley and rye, it has 

 never been reared on other grains or grasses. Its name was re- 

 ceived from the fact that it was first noticed on Long Island in 

 1779, near where the Hessian troops had landed three years before. 

 It now occurs over the main wheat-growing area of the eastern 

 United States between parallels 35 and 45 westward to the 100th 

 meridian, on the Pacific coast, in Canada, and in many other parts 

 of the world where wheat is grown. Xot infrequently it destroys 

 25 to 50 per cent of the whole crop in some localities, and it has 

 been estimated that 10 per cent of the crop of the whole count ry 

 is lost from its ravages. 



Life History. The adult flies are little dark-colored gnats about 

 * Mayetiola destructor Say. Family Cecidomyidw. 



