484 THE SMALL GRAINS 



the females are wingless or have wings greatly aborted. Eggs are 

 deposited about May 1, near the beginning of the young wheat 

 spike, not far above ground. The adults of the second brood are 

 much larger, and consist entirely of winged females. They are 

 therefore able to fly and are the migratory brood. Eggs are de- 

 posited in or near the joints of the culm, usually near the second 

 joint from the spike. The worms reach the pupal stage within the 

 straw in the fall, and emerge as adults the next spring. 



These insects are attacked by several parasitic flies, 

 which check their multiplication greatly. The remedy 

 for the straw-worms is in burning the stubble which har- 

 bors the over-wintering stages and in crop rotation. 



529. The bulb-worm (Meromyza americana, Fitch) in 

 the adult stage is a minute yellowish-green 2-winged fly, 

 quite different from the Hessian fly, and found on all 

 the small cereals and other grasses. It is not nearly so 

 destructive as the Hessian fly, but sometimes causes con- 

 siderable loss. It occurs throughout eastern North 

 America, from Canada to Texas. There are at least 3 

 broods in the latitude of Ohio, and maybe one or more 

 additional broods in the South. 



The fall brood passes the winter in the larval stage at 

 the crown of the cereal plant. Adults emerge the next 

 June, and deposit their eggs, often several in a row, near 

 the edge of the sheath of the upper leaf. The resulting 

 larvae or maggots feed on the succulent portions of the 

 culm, just above the last joint, and cause the upper 

 portion of the straw to wither and die, and the spike 

 to turn white. The adults of this second brood 

 leave the straw in July and August, and breed in 

 volunteer grain or grasses, and start a third brood in 

 time to infest the winter grain in September and 

 October as before. 



