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“The time for its last transformation having arrived, the pupa, by 
writhing and bending its body, breaks open its puparium or flaxseed 
case, crawls from it, and works its way upward within the sheath 
of the leaf until it comes to some cleft in the now dead, brittle and 
elastic straw. Through this cleft it crowds its body until all except 
the tip of the abdomen is protruded into the air, the elasticity of 
the straw causing it to close together upon the tip of the abdomen 
sufficiently to hold the pupa in this situation secure from falling to 
the ground; and, as if to preserve the body in a horizontal position, 
the feet are slightly separated from the abdomen and directed 
obliquely downwards, with their tips pressed against the side of the 
straw, thus curiously serving, like the brace to a beam or to the arm 
of a signpost, to support the body from inclining downwards. Thus 
securely fixed and now freely exposed to the drying influence of the 
atmosphere, the outer membrane of the pupa exhales its moisture, 
and, as it becomes dried, cracks apart upon the back or upper side 
of the thorax. Out of this opening the inclosed fly protrudes its head 
and thorax, more and more, as it gradually withdraws its several 
members—the antennae, wings and legs—from the sheaths in which 
they are respectively enveloped—a process analogous to that of with¬ 
drawing the hand and its several fingers from a tight glove—until at 
length, entirely freed from its pupa-skin, the fly, now perfect m all 
its parts, usually walks a few steps further up the straw, where it 
pauses for its body and members to acquire more firmness and 
strength by the further evaporation of their moisture, after which it 
is ready to spread its wings and mount into the air.” 
The Hessian-fly is easily distinguishable in all its stages from the 
wheat midge, which belongs to a different genus, Diplosis ( D . tritici 
of Kirby). The wheat midge is orange-colored, has a stouter body, 
with clear, transparent, and much broader wings, and pale yellow 
legs, while the larvae are orange-colored, and live crowded around 
the wheat grains at the top of the plant; they spin a silk round 
genuine cocoon, smaller than a mustard seed, which remains in the 
ground just beneath the surface. So it will be seen that the forms 
and habits of the two insects are very dissimilar, and they need not 
be confounded. 
HABITS OF THE HESSIAN-FLY. 
Having become acquainted with the appearance of this two-winged 
gall-fly in its different stages, we are now prepared to study its 
habits; for an intimate knowledge of how it comports itself as an 
egg, larva, “flaxseed,” and perfect winged fly, is absolutely essential 
to the farmer who would endeavor intelligently to combat this pest. 
Number of broods. —The Hessian-fly is double-brooded; the “flax¬ 
seeds,” or puparia, being found on the winter wheat from late in 
the autumn, through the winter, until the early part or middle of 
April. The “flaxseeds” of this brood, from one to about twenty in 
number, are situated between the stalk and sheathing base of the 
leaf, at the roots of the young grain, slightly beneath the surface of 
the ground. 
