28 
CORN AND GRASS. 
Gout Fly ; Ribbon-footed Com Fly. Chlorops tceniopus, Meigen. 
CHLOROPS TiENIOPUS. 
2—6, 11, maggot, chrysalis, and fly, nat. size and magnified ; 7 and 8, Ccelinius 
niger; 9 and 10, Pteromalus micans (parasite flies), nat. size and magnified ; 1 and 
12, furrowed Corn stem. 
The attack of the Chlorops , or Gout Fly, is one of the very com¬ 
monest and most regularly recurring of those insects injurious to the 
growing Barley ear and stem that we have in this country; and all 
moderately observant agriculturists cannot fail to know the presence 
of the infestation well, by the swelled and deformed growth of the 
sheathing-leaves of the ear, which sometimes, as in the opposite 
figure, is unable to escape from them, and remains as a stunted plant 
for life. 
More frequently, however, it wholly or partially escapes, and then 
the attack is recognisable by more or less of the lower part of the ear 
having been destroyed by the fly maggot, and a brown or blackish 
channel being observable from the ear down one side of the stem to 
the uppermost knot (see figure). Here the legless whitish maggot 
has fed its way onwards, and there it turns, within the sheathing- 
leaves, to a rusty-brown chrysalis, from which the little stumpy-made, 
two-winged, black-and-yellow flies come out very soon, and may be 
found sometimes, as I have found them myself, in such numbers in an 
infested stack just harvested, that when I have thrust one arm well 
down amongst the straw I could sweep the flies out in such numbers 
that they fell fairly rattling down on the sheet of paper I held below. 
