INSECT ENEMIES OF WHEAT 175 



THE CHIEF LOSSES are occasioned in the Ohio and upper 

 Mississippi valleys, and on the Atlantic coast highland. It 

 does more damage to wheat than to any other crop, and the 

 average annual loss is about 5 per cent of the crop. 1 In years 

 when the chinch bugs were unusually severe, the damage to 

 wheat in single states has been estimated to be from ten to 

 twenty million dollars. The losses are great because of the 

 wide distribution of the pest, its prevalence to some extent 

 every year, and its enormous multiplication in favorable sea- 

 sons. 



REMEDIES. (1) Burning over the land; especially should 

 this be done on waste and grass lands, and all rubbish should 

 be burned. Grass is not injured by being burned over after 

 the ground is frozen. It has been thought that the chinch bug 

 was kept in check by the annual prairie fires in the early years 

 of our country, the hibernating bugs being thus killed. Chinch 

 bugs and other insects injurious to growing grain are practi- 

 cally unknown on the Pacific coast, where the large wheat 

 fields are regularly burned over every year by burning the 

 straw. (2) Trap or decoy crops, such as millet or Hungarian 

 grass; these should be plowed under. When the young insects 

 hatch, they easily reach the surface, but will perish if no 

 crops are near. (3) Rotation; this involves a system disas- 

 sociating small grains from corn. (4) Plowing; deeply plow- 

 ing under the bugs collected on the edge of a field is help- 

 ful. (5) Spraying; the edge of the field infested may be 

 sprayed with a very strong oily insecticide, even if the crop is 

 killed with the bugs. (6) Protecting furrows. (7) Coal-tar 

 barriers. (8) Artificial spreading of parasitic fungi; consid- 

 erable work has been done in this line, with the conclusion that 

 it is of little value. The bug is practically exterminated for 

 the season, however, by wet weather and various fungous dis- 

 eases which this causes. (9) Many bugs are also destroyed by 

 birds, especially quails. 2 



The Wheat Midge (Diplosis tritici Kirby) belongs to the 

 same order of insects as the Heesian fly, but in appearance and 

 habit it is entirely distinct. It is believed to be identical with the 

 notorious wheat midge of Europe, and it may also have been in- 



1 Yearbook U. S. Dept. Agr., 1904, p. 466. 



2 Webster, The Chinch Bug; Howard, The Chinch Bug. 



