50 ON THE CECIDOMYIA DESTRUCTOR, OR HESSIAN FLY. 



If the larva remains in tbe same place and position, from the time of its ex- 

 clusion from the egg to the pupa state, how does it get from near the root to 

 the third joint, and sometimes, although rarely, above it, as the facts prove? 



Again, I would ask, if the perfect fly appears in June, lives only a short 

 time, and in that time the female deposites her eggs, where are those eggs placed? 

 surely not in the old and dying stalk of wheat from whence she has derived 

 her subsistence ; and I know of no other plant on which she feeds. Mr. Say 

 continues, " the insects from these eggs," deposited in June, '' complete the 

 history by preparing for the winter brood;" we are here left in the dark re- 

 specting the home and food of this second brood, since there is no wheat grow- 

 ing from June until September, when the grain is again planted. 



Had the information of Mr. Say, respecting the history of the insect, been 

 as accurate as his knowledge of its appearance, he would not have left room 

 for these doubts. The eggs described by Mr. Say, I am compelled to believe, 

 were those of some other insect, which he has mistaken for those of the Hes- 

 sian Fly, as they appear to have been found where his previous impression led 

 him to search for them. 



My first observations were made in June, 1836, when the Hessian Fly was 

 making its ravages around us. The insect was then in the pupa, as shown by 

 Mr. Le Sueur's beautifully correct drawings, in the first volume of the Journal 

 of the Academy of Natural Sciences, illustrating Mr. Say's description of the 

 insect. The pupae were scattered from the root to the third joint of the straw, 

 and the wheat was beginnidg to ripen, although still soft. In a few days the 

 flies made their appearance in countless numbers, hovering over and settling 

 on the ears of wheat, where they were, no doubt, depositing their eggs in the 

 grain, thus securing a home and future food for their progeny. In about ten 

 days they had all disappeared, and the impoverished grain ripened for the 

 harvest. 



In 1837, a field was sown so late that the grain did not vegetate until the 

 following spring. I watched it closely, but could not observe that any injury 

 was sustained until the beginning of May. Then I detected the worm in the 

 root, and, in many instances, in the old grain, where it had originally been de- 

 posited, but seldom or ever above the first joint of the straw. I am not pre- 

 pared to say positively at what time the worm passed into the pupa, but be- 

 lieve it to be about the beginning of June, From this field I preserved a 



