GRASSHOPPERS AND OTHER INJURIOUS INSECTS OF 1911 AND 1912. 



47 



The Fly which produces the Wheat Stem Maggot is much 

 smaller than the housefly, yellowish or greenish yellow in color. It 

 lays its eggs on the plants in the spring and after hatching the 

 maggots enter the stem. Feeding as they do above the upper joint, 

 sap cannot enter the heads and the latter die before 

 the grain matures. Late in July or early in August 

 these maggots change, within the straw, to puparise, 

 from which in time come the flies which mate and 

 lay eggs on wheat. It is also said to attack several 

 grasses. In the volunteer grains and wild plants the 

 maggots spend the winter, turning into puparia in 

 the spring, the flies emerging a little later. 



Nothing can be done, of course, when "bald 

 heads" are seen in the grain, it is then too late for 

 Fig. 32. Qaii-iike dis- action. In stacked grain the insects which are away 



tortions of Wheat '' 



Stem caused b y f rom the surface, toward or at the center of the 



presence ot joint 



worm. stack, nevcr escape, and these perish. Hence, as re- 



gards this insect, threshing from the stack is better practice than 

 threshing from the shock. Early threshing, say the last of July or 

 in the first week in August, doubtless kills many of the flies. After 

 harvesting, all volunteer plants and will stuff growing over the 

 field and particurally along fence rows, should be plowed under. 

 Rotate, after wheat, barley and rye, with some crop other than 

 these grains. Corn might well follow wheat. Field men report 

 that the injury from these insects last summer was largely confined 

 to "Velvet Chaff" while "Blue Stem" was almost free from injury. 



