INSECTS. 125 



a loss of from one-half to an entire crop. The 

 Hessian fly is a wheat insect, but it will also breed 

 in a few other grains. 



The adult insect is a small fly about one-eighth of 

 an inch long, and dark in color. Like all flies, it 

 passes through four distinct stages egg, larva, 

 pupa, and adult. The pupa stage for this fly is 

 known as the "flaxseed stage," owing to its resem- 

 blance to that seed. 



The second, or maggot, stage is the one that 

 does the damage. Eggs are laid by the adult on 

 the leaves or stems of wheat. They hatch in a few 

 days, and the white maggots eat the tissue and 

 suck the juices from the stalks. Sometimes their 

 injuries cause enlargements to grow on the stems 

 at the point of attack. If the injury is great, the 

 plant falls to the ground. 



Most wheat plants respond to the injury by send- 

 ing up new, shoots; but these, in turn, are generally 

 infested, so that only a partial crop is the result. 

 Hardy varieties, that is, those with hard, flinty 

 stems, sustain the least injury because the straws 

 .do not bend easily at the injured points. 



No remedy has been found to save a field when 

 once infested with the Hessian fly, but careful 

 measures may save succeeding crops. Since the 

 flies work on the lower joints of the stem, they 

 may be left in the field by cutting the wheat high. 

 If the stubble is then burned, they may be destroyed. 

 Another effective measure is to plow under the 



