190 



INSECTS AFFECTING FIELD CROPS 



yellowing of the head and of the stalk above the infested point, 

 generally three or four inches above the ground. This is followed 

 by a breaking down of the plant. Just below the point of breaking 

 the maggot can generally be found within the stem. 



Control. If straw is stacked, many hibernating insects will not 

 be able to reach the surface of the stack. Burning or feeding up 

 the straw will, of course, destroy all wintering forms. In regions of 

 spring-sown wheat, burning the stubble in the fall, where possible, 

 is a good remedial measure, as is also the plowing under of stubble. 

 The latter method is the most practical in the northern states. 





Y 



FIG. 209. The frit-fly: a, imago; 6, larva or maggot; c, puparium containing the pupa. 

 All much enlarged. (After Lugger.) 



The Wheat-head Army Worm (Meliana albilinea Hbn.). 

 This is one of the cut-worm moths. The female lays her eggs on 

 leaves of different grains, timothy and other grasses. The worms 

 are observed at work in June and July and have been found 

 entering the pupal stage in the middle of the latter month. 



Injury. Timothy sometimes suffers seriously. Four-fifths of 

 the timothy seed crop has been known to be destroyed during one 

 season, and the hay crop seriously injured. On wheat the worms 

 eat the kernels of the grain, allowing the chaff to fall to the ground 

 (Fig. 210). 



