117 
eating off the green straw just above the upper joint. I could 
see no striking difference in the appearance of the puparium, 
but yours was outside of the stem and underneath the sheath. 
(Evidently this was an exceptional case). I believe our insect 
always pupates in the stem among the frass and refuse left by 
the larve. That these flies are closely allied if not identical, 
I am convinced, but I hesitate to say that yours is typical 
Meromyza americana, and Fitch’s description does not solve the 
problem.” A careful comparison has convinced me that the 
insects bred from Minnesota wheat-straw are identical with 
those bred from more eastern and southern straws, and that 
the flies vary among themselves to a sufficient extent to account 
for extreme differences that may occur. 
THE HESSIAN FLY. 
(Cecidomyia destructor Say.) 
The history of this destructive fly in more southern regions 
is briefly as follows: there are ordinarily two broods which 
appear during May and June, and later during September and 
October. The fly is a small two winged insect, dusky in color, 
and about one-eight of an inch in length (Fig. 60). The male 












Fig. 60. Hessian Fly. 1. Adult female; 2, | Male abdomen; 38 Pupa removed 
from “‘Flax-seed”’; 4, 5 Larva; 7, ‘“Flax-seed”’ in position. 
is very slender, and the female, when ready to deposit her 
eggs, a little stouter. The eggs, oval and bluntly pointed at 
each end, are about one-fiftieth of an inch long, and of a dull 
