STATE AGRICULTURAL SOCIETY. 
833 
JOINT-WORM FLY. FLIES HATCHED FROM THE STRAW. 
substance of the sheath, near its base. On separating the sheath 
from the culm and drawing it aside, the worm is not exposed to 
view: it lies in the texture that is thus separated, and can only 
he seen by cutting into the elevated or blistered spot already 
spoken of, which spots are equally manifest on the inner as they 
are upon the outer surface of the sheath. 
Dr. Harris on reading the above description observed that this 
joint-worm occupied the identical situatipn in the straw with an 
insect which some years before had infested the barley in Massa¬ 
chusetts, from which he had obtained what was supposed to be 
the parasitic destroyer of the real culprit, and which he had 
described under the name Eurytoma Hordei. A correspondence 
upon this subject took place between us, and we mutually con¬ 
cluded the parent of this joint-worm would prove to be a Ceci- 
domyia of the same species, probably, with that which had 
infested the barley. 
In March of the following year Mr. Ruffin forwarded to Dr. 
Harris a quantity of the diseased straw, which he, to be more 
secure in having specimens of the perfect insect obtained there¬ 
from, divided into two unequal parcels, the larger one of which 
he transmitted to me. An examination of these samples showed 
that this insect was not constantly confined to the substance of 
the sheath above the joints, where I had previously found it, but 
was sometime lodged in the joints themselves, whereby their 
texture becomes swollen and distorted; and in a few instances 
the cells containing the worms are found to be in the walls of the 
central stalk or culm, wholly inside of the sheath. 
These straws placed upon moist earth in a glass jar, the most 
natural situation I could give them, and kept in a stove warmed 
room, began to give out the flies profusely on the 28tli of April, 
between which date and the 6th of May when the hatch termi¬ 
nated, upwards of a hundred specimens were obtained. To my 
great surprise no Cecidomyia flies were disclosed. They were 
all alike and on careful inspection all were found to be females, 
very similar to if not identical with the Eurytoma Hordei from the 
Massachusetts barley. The parcel which Dr. Harris retained, 
was placed in a dry jar, and yielded him a few days later, fifteen 
of the same flies, all females save one. These results, in connec¬ 
tion with the fact that no other insect but this had been obtained 
from the Massachusetts barley, could not but excite our strong 
[Ag. Trans.J 53 
