THE HESSIAN FLY, 3 
the ‘‘flaxseed,”’ the color varying with age, the posterior segments 
terminating in a compressed cylindrical, very minutely hairy ovi- 
positor, capable of great extension. The male (fig. 2) is smaller, 
more slender, and in color generally darker than the female, the 
abdomen terminating in a somewhat intricate organ composed of 
a set each of outer and inner claspers. 
The egg (fig. 3) is very minute, being only about one-fiftieth of an 
inch in length, cylindrical, roundingly pointed at the ends, glossy 
translucent, and slightly reddish, this color deepening with develop- 
ment. 
The larva or maggot (fig. 4), when newly hatched, is a little smaller 
than the egg, with a slightly reddish tinge; later, as it increases in 
size, it is at first white and afterwards greenish white, clouded inter- 
nally by flaky white. 
After the larva has reached its full growth and the skin has hard- 
ened and turned brown, forming a covering known as a puparium, 
the insect is known as the flaxseed (fig.6). There 
is at this time a minute, brown, forked process on | | | 
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the underside of the anterior end of the larva, 
known as the “‘breastbone”’ (fig. 5), the use of 
WHERE TO FIND THE DIFFERENT STAGES. Fig. 3.—Egg of Hessian fly, 
greatly enlarged; section 
which is not fully understood. It is not present, 
however, until the larva enters the flaxseed state, 
Within this ‘‘flaxseed”’ it transforms first to a 
pupa (fig. 7), and from this to an adult fly. The 
term ‘‘flaxseed’’ is applied partly because of its 
brown color and partly because it 1s more or less 
flattened, thus giving it somewhat the appear- 
ance of a flaxseed. 
From the foregoing descriptions it will be ob- — ofleafof wheat, at right, 
5 : te Sane showing eggs as usually 
served that during the life of this insect it is deposited, less enlarged. 
found in four very different forms, so entirely — (Auther’sillustration.) 
unlike in appearance as to confuse the average farmer. 
The eggs (fig. 3), which may be easily seen by one with fairly 
good eyesight, are generally placed in the grooves of the upper surface 
of the leaves, though they are occasionally found on the underside 
of the leaf. When the young wheat plant is just pushing through 
the ground, the egg is sometimes placed on the outside, because no 
leaves are available. 
The young larva is slightly smaller than the egg, and as soon as 
it is hatched it makes its way down the leaf and behind the sheath. 
In case of young wheat it descends to just above the root, but after 
the plants have begun to joint it can go no farther than the base of 
the sheath belonging to that particular leaf, which is always at the 
