INSECTS INJURIOUS TO SMALL GRAINS 



139 



worm is fatal to the plant affected, as no grain at all is produced, 

 and while the second generation of the same has a less disastrous 

 effect in the field, it nevertheless reduces the grade and weight 

 of the grain." Though the straw-worm occurs over much of 

 the same territoiy in the East as the joint- worm, it is rarely so 

 injurious. 



Life History and Description.* " There are two generations 

 of the insect annually, the adults of the first generation differing 

 considerably in appearance from those of the second. To the 

 farmer they will all look like minute or large, shining black ants, 



FIG. 101. Wheat straw-worm: adult of fall generation, much enlarged. 

 (After Howard, U. S. Dept. Agr.) 



with or without wings, their legs more or less banded with yellow, 

 and having red eyes. Individuals of the first generation emerge 

 in April from the outstanding straws and stubble. They are 

 very small, most of them are females, and many are wingless. 

 The females deposit their eggs in the young wheat plants, the 

 stems of which at this time extend but little above the sur- 

 face of the ground. The egg is placed in or just below the 

 embryonic wheat head and the larva or worm works within 



* From Circular 106, Bureau of Entomology, U. S. Dept. Agr., by F. M. 

 Webster and Geo. I. Reeves. 



