834 
ANNUAL REPORT OF NEW YORK 
JOINT-WORM FLY. PROF. CABELL’S INVESTIGATIONS. 
suspicions that this fly was itself the real depredator upon the 
wheat and not a parasite which had in such a multitude of 
instances killed the destroyer to come out thus in its stead. 
But as all the family of insects to which this species pertains 
were currently regarded by authors as parasitic, and we were 
acquainted with American species of this same genus Eurytoma 
which we had conclusive evidence were parasites, we could not 
but hesitate in adopting this view. 
Prof. J. L. Cabell, of the University of Virginia, residing in 
the midst of the region where it was so destructive, was simul¬ 
taneously directing his attention to this insect. In the spring 
of this same year, 1852, from different parcels of wheat he bred 
flies to more than a hundred in number, obtaining the same insect 
in every instance. In examining the worms in the diseased 
straw he met with two kinds, one being yellowish, smooth and 
sluggish; the other white, hairy and very active in its move¬ 
ments. This last was evidently a parasite. In several instances 
it was found in the same cell with an individual of the first kind, 
and feeding upon it, but at all times it was found in an exceed¬ 
ingly small proportion of cases, not more than one in twenty or 
thirty. Prof. Cabell embodied the results of his investigations 
in an article which was published in September, 1852, in the 
Southern Planter, vol. xii, pp. 271, 272, in which the fly obtained 
from the joint-worm was announced to be the Eurytoma Hordei, 
Harris, to which he adds that everything concurred in confirming 
his first impression that the mischief to the wheat was occasioned 
exclusively by this insect, and that he was obliged to hold to 
the opinion, at least until another fly was produced, that ento¬ 
mologists have made a premature generalization in ascribing 
exclusively carnivorous habits to the group of insects to which 
the Eurytoma belongs. 
It will readily be seen that the question whether this Eurytoma 
was a phytophagous or a carnivorous insect, a vegetable feeder 
or a flesh eater, whether it was the real parent of the joint-worm 
or its most inveterate foe, and consequently whether it should 
be combatted and destroyed or cherished and protected, was no 
less interesting in a scientific than it was important in a prac¬ 
tical point of view. IIow could the real fact be ascertained ? 
I felt confident that il 1 was personally present where this joint- 
worm abounded, I could assuredly observe it so closely and obtain 
