24 
distance. In Hancock county, in Western Illinois, late in June, not oxt 
two or three per cent, of the heads were blighted m the fields won 
infested, and a still smaller ratio were damaged in the rye adjacen 
In every case the head was destitute of kernels, and its growl 
had often been arrested before it had reached full size. On strij 
ping down the sheath of the upper leaf, the stalk was alwaj 
found eroded and withered for a distance of an inch or so abo^ 
the internode, and the stem could, of course, be readily pulled 01 
from the enclosing sheath. In Prof. Kiley’s notes of the work . 
this brood near St. Louis, Missouri, he remarks: “In most fiea 
about one per cent, of the ears w 7 ere thus affected, but in two fielc 
near Hermann from three to four per cent. w T ere injured in tbj 
manner. Upon examination, I found that the last or ear-bearii 
joint could invariably be pulled out of its sheath with but a slig. 
effort, and that it was perfectly yellow and dry, while the lower ei 
bore an irregular and gnawed appearance. Upon splitting open t. 
first joint of the stalk, a space of about a quarter of an inch w 
found to be completely corroded, so to speak, and filled with exci 
mentitious matter.” Prof. Lintner says: “The heads were entire 
destitute of kernels. Within some of the husks the remains of tj 
blossoms were discoverable, showing that their development h; 
been arrested before the formation of the grain. Upon removfj 
the investing sheath, the stem was found to be discolored. a: 
shrunken, and quite dry for three or four inches above the joiij 
and near the joint it was so eaten and shriveled as to be uttei 
useless for the purpose of conveying the sap.” 
It will be seen that the injury done by this insect in fall a 
spring, while similar in its effect to that of the Plessian fly, is quj 
different in character. Both insects, indeed, infest the same part 
the plant at the same season, but the Hessian fly does not gnaw 
tear the substance of the stalk. It seems to depend rather upon t 
effect of the pressure of its body imbedded within the sheath 
arresting the flow of sap and causing it to exude from the stem. 
The second attack of the bulb worm is not only made in a c 
ferent way, but at a different point from that of the Hessian 1 
the latter still confining itself to the lower part of the stalk, a 
damaging the wheat, as before, through the irritation caused by 1j 
presence of the larvae within the sheath; while at this time, i 
already related, the bulb worm attacks the plant and destroys 
stem above the upper joint. 
NATURAL ENEMIES. 
The fact is well known that to the aid of parasites we owe 
preservation of our wheat crops from continuous injury by the if 
sian fly,—parasites which effect their purpose by piercing 
bodies of the larvae imbedded in the plant, and depositing in e: 
a minute egg which afterwards develops a maggot that devours i 
host. The wheat Oscinidae of Europe are also kept within boul 
by a parasite of similar habit, known under the name of Ccelit I 
niger, and the presumption was consequently ver}' strong that sc: 
corresponding enemy of our own species would be found. 
