HESSIAN FLY. 
13 
then found that the maggot, of which the chrysalis was sent, was the 
cause of the attack ; and in the report of the attack from near Perth 
there is similar mention of the broken-down stalks and small brown 
pup^e found at the injured part. 
On examination in the fields near Hertford, on the 30th of July, I 
found the stems doubled sharply down a little above the joint, as 
shown in fig. 1, No. 1, and between this double and the joint below 
there lay, closely pressed to the stem and covered by the sheathing- 
leaf, the flax-seed-like chrysalis-cases, figured on the right hand of the 
bent stem. The injury is caused by the fly-maggots lying at the same 
spot sucking the juices from the stem, which is thus weakened, and 
presently, although both the stem and the ear above are more or less 
stunted, yet the weakened piece of stem cannot bear their weight, and 
it bends sharply down at the injured part. Sometimes a gall or some 
amount of swelling of the stem occurs just above where the maggot 
fed, but in the specimens I examined this was rarely noticeable. I 
am told by Mr. John Marten, of Albion, Illinois, U. S. A., an economic 
entomologist who has especially made a study of this attack, that the 
specimens I showed him corresponded in absence of gall with the 
condition of those in Illinois. 
