53 
are assured a midge-fly is this species when it possesses all 
characters. But many flies also pertain to this species which 
fully possess them, some departing from the standard in one, 
in another particular, whereby it happens that no one of 
characters is constant and found in all the members of this 
. All the bright yellow midges which occur in our wheat 
luring the latter half of June may be regarded as the wheat 
i 
LIFE HISTORY. 
fly or perfect insect makes its appearance in ordinary seasons 
h before the middle of June, in the latitude of New York, but 
ching varies with the latitude and the progress of vegetation. 
ool season hastens, a cold season retards insects and vegeta- 
; ike. Under ordinary circumstances this fly lives about three 
but if the season be wet and the fly numerous it is seen 
much longer, sometimes until the middle of August. Mois- 
Lf its life, dryness smothers and suffocates it, consequently it 
remain upon the wheat heads during the heat of the day, 
fits upon the lower part of the stalks until the sun begins to 
, when it returns to its operations upon the heads. On damp 
days the insect is as active in the day as at night, and 
shaded by trees, or wheat on low lands, are the most severely 
ill. If at the time the fly is abroad, depositing its eggs, the 
r be extremely dry, the crop escapes; if unusually wet 
r prevails, the grain will be severely injured. 
le deposition of its eggs the only aim of the fly seems to be 
Lee them in some crevice of the headlet where they will be 
ratively secure from enemies, and sheltered from the sun and 
lich would shrivel them. From the form apd character of 
lipositor it is evident that the fly is restricted to crevices for 
posit of its eggs. They are, perhaps, most commonly placed 
little orifice at the summit of the outermost chaff, but may 
ad in any narrow opening upon the headlets which the fly is 
> discover. Sometimes a single egg is found, but they are 
! r in clusters of from two to ten. The young larvae appear in 
a week after the egg is laid. In whatever situation hatched, 
iust find their way at once to the germ or kernel from which 
erive sustenance. Attaching themselves first at the base of 
j rnel they afterwards, as they increase in size, usually with- 
arther up the side. The larvae mature in about three weeks 
ay often be seen descending to the ground as early as July 
ile some of the parent flies are still depositing their eggs. 
}f the larvae throw themselves to the earth with a skip from 
irds; others crawl down enveloped in a pellicle of water; and 
hers crawl in a serpentine track till the globule of water in 
the larva is moving becomes so large that it is upon the 
>f running down the straw, when the larva lets go its hold, 
carried to the earth. 
a mistake to suppose that only the larvae which go into the 
before harvest live and produce the flies of the following 
Experiments indicate that few if any of the larvae would be 
k 
i 
