4 FARMERS’ BULLETIN 640. 
joint. Where excessively abundant, the larve will frequently be 
found on the lower stem ranged one behind the other, the anterior 
end of one pushed slightly under the posterior end of the one in 
advance. Very often this position 1s maintained throughout the 
entire development of the larva (figs. 4 and 5), and the flaxseeds 
(figs. 6 and 10) still retain the same relative position. 
The fall generation of larvee and the overwin- 
tering flaxseeds are to be found just above the 
roots (fig. 10), except in cases where the young 
plant has become disintegrated and separated 
at the point of attack in the fall or the plants 
have been heaved out by the action of freezing 
and thawing, in which case they may be scat- 
tered about on the surface of the ground. 
The young make their way down the plant 
head foremost, and so remain until before 
ae eee san iy: 12%" pupating, when they reverse their position 
Much ealarged. (Author's it in the flaxseed and are then situated head 
ao upward, and thus pass into the pupal stage. 
Before the fly issues, however, if the flaxseed ts not situated con- 
veniently for its escape, the pupa will push itself, if possible, to such 
a point, and frequently empty pupa skins may 
be observed protruding from under the sheaths res a 
of the leaves. 
The fly itself is not easily observed until 
one becomes familiar with its appearance, and 
this will account for the great variety of insects 
that are continually mistaken by farmers for 
the Hessian fly. Much of this difficulty may 
be obviated if farmers will look for an insect 
like that shown in figure 1, but very minute 
and somewhat resembling a very small mos-  Fre.5.—The Hessian fly: Larva 
quito. During warm days, in the egg-laying raced, Gah hee 
season, the flies may be observed flying about _ still more ealarged at right. 
in the young wheat, alighting upon the leaves. (A™HorsHiusization.) 
In cooler days, or in early morning while a heavy dew is on, they will 
be down among the leaves, or even on the ground. 
LIFE HISTORY. 
At present all indications point to the probability that the Hessian 
fly has two generations, at least during favorable seasons, over its 
entire area of distribution in the United States. 
In the South the two generations are the most widely separated, 
while in the North, in the regions of spring-wheat growing, one seems 
to follow the other in quick succession. 
