714 NEW YORK STATE MUSEUM 



young plants in wheat fields, it is very likely to be this notorious 

 pest. 



The puparium or " flaxseed " stage is so well known that a 

 description is hardly necessary. The " flaxseeds " are about -J 

 inch long, of light brown color and occur near the base of the 

 plants. One very much enlarged is represented at f in fig. 1. 



The slender, delicate, greenish white maggots are also some- 

 what familiar to the wheat grower and a detailed description of 

 them in this connection is hardly necessary. The full grown 

 larva is about J inch long and it is usually found in the field 

 between the sheath and the stem of the young plants. 



The eggs have been sufficiently characterized in a following 

 paragraph treating of their deposition. 



Food plants. The food plants of the Hessian fly are of con- 

 siderable importance because if it is able to subsist on a num- 

 ber of grasses and grains its control is manifestly much more 

 difficult. The Hessian fly was early recognized as a pest of 

 wheat, rye and barley, and despite the fact that records are 

 occasionally met with of its occurrence in timothy and other 

 grasses and grains, the weight of evidence seems to indicate that 

 it does not live to any extent at least on anything but the above 

 crops. It is possible that at exceedingly rare intervals, com- 

 paratively speaking, a few may mature on timothy, but in some 

 instances at least related species have been confounded with it. 



Life history. Normally there are two generations in this latitude 



though there may be several supplementary ones. The adult fly 



may deposit from 100 to 150 eggs, according to Marchal, placing 



them between the ridges on the upper surface of the blades of 



young wheat. Individuals of the spring brood occasionally 



thrust their eggs beneath the sheaths of the lower leaves. The 



process of oviposition has been carefully described by Mr Her- 



rick as follows: 



While depositing her eggs the insect stands with her head 

 toward the point or extremity of the leaf, and at various distances 

 between the point where the leaf joins and surrounds the stalk. 

 The number found on a single leaf varies from a single egg up 

 to 30 or even more. The egg is about ^ inch long, cylindric, 

 rounded at the ends, glossy and translucent, of a pale red color, 



