134 Flies [CH. 
after favourable ‘seasons, and that late sown oats are 
always liable to be attacked. 
Gout Fly (Chlorops taeniopus). 
This fly attacks barley, wheat, rye, and certain 
grasses. In this country the injury to the barley crop 
is often very serious. 
In a badly attacked plant the shoots are swollen 
considerably suggesting the name “gout.” The ears 
are usually unable to force their way through the 
leaves which become spirally twisted at the top (see 
Fig. 40). A groove is eaten out along the upper 
part of the stem and the lower grains are usually 
shrivelled. The plant itself is stunted and distorted. 
On cutting open a diseased plant at the earliest stage 
of an attack a small maggot may be found feeding on 
the upper portion of the stem. This larva of the gout 
fly is somewhat similar to the frit fly maggot, only 
considerably larger. One maggot only is usually 
present in each shoot. When fully grown it measures 
from }-3, inch in length (see Fig. 41.4). It has a semi- 
transparent, shining, fleshy appearance and is yellowish 
in colour. It possesses no legs and is segmented. 
The contents of the gut can be seen through the body 
wall. At the pointed anterior end are a pair of small 
black jaws, and at the posterior end a pair of spiracles 
protrude. If we examine a diseased plant later in the 
season we shall find that the maggots have changed 
into pupa cases. The pupa case is slightly smaller and 
of a brownish colour (see Fig. 41 B). 
From these the flies hatch out in August and 
September. They may be hatched out by keeping 
puparia in a bottle covered with muslin. They are 
