836 
ANNUAL REPORT OF NEW YORK 
JOINT-WORM FLY. A MIDGE LARVA ALSO IN THE WHEAT. 
Upon this subject I would observe that I have in instances 
without number, with the aid only of the common pocket mag¬ 
nifier, noticed the jaws in the larvae of various species of Ceci- 
domyia appearing as two minute black lines meeting at an acute 
angle, in the form of a letter V or sometimes like a Y, and have 
mentioned this in my published descriptions of some of these 
larvae. More recently the larvae of numbers of the gall bees 
have come under my examination, in the larger ones of which, 
the jaws are equally distinct, forming a straight transverse line 
slightly interrupted in its middle. Prof. Cabell is undoubtedly 
correct in regarding this as a decisive character whereby we may 
know whether the larvae we meet with in galls pertain to the 
order Hymenoptera or Diptera. 
But this instead of diminishing our doubts upon the question 
at issue — whether the Eurytoma is or is not a parasite — greatly 
increases those doubts. It sufficiently proves that the worm 
which Prof. Cabell found in the wheat is the real larva of the 
Eurytoma; and Prof. Cabell and Dr. Harris hence inferred that 
I was in error in pronouncing the worm which I found in the 
Virginia wheat from Mr. Rives to be a Cecidomyia. But that 
by no means follows. On the contrary, the very character stated 
renders it quite evident that 1 was correct. I was at that time 
perfectly familiar with the appearance of the mouth in the larvse 
of the Cecidomyiae, and of the Hessian fly in particular. Had 
there been any perceptible variation therefrom in the larva 
examined, I think I could not have failed to observe it and to 
have noticed it in the careful description which I drew up. In 
that description I say, “ The worm is soft, shining, of a uniform 
milk-white color,” not at all yellowish therefore, like the Eury¬ 
toma larva, and no green central cloud as in the Hessian fly 
larva; and observe what follows, “and on its anterior end is a 
a small V-shaped brown line, marking the situation of its mouth.” 
Now this V-shaped brown line is the jaws, their ends coming 
together at an acute angle. It is clear, therefore, that the worm 
sent us from Mr. Rives as being the joint-worm was a different 
species from that which Prof. Cabell found in the wheat the fol¬ 
lowing year, and was undoubtedly a Cecidomyia, as I supposed 
it to be. It was not till some considerable time afterwards that 
I became aware of this. When I was first informed of the dis¬ 
tinctive mark which Prof. Cabell had ascertained to exist 
