Martinsburg gazette. [volume] (Martinsburg, Va. [W. Va.]) 1833-1855, 1845-10-02

Err, Esq, Editorsof the Western Farmer and
Gardner"
THE UESsIAN FLY--Cecidomyia Des-
tructor.
This is small and too well known
nudge, greatly injurious to wheat. This
minute insect, Of the order OF two-wingsd
flies, Diptera, OF Linnaus, has done OF
late years great deal Of damage TO ous
wheat crops 10 this country, as well as IN
Europe, and ia some places occasloned
dearth aud famine by lis devastatlons.-
We call this fly the Hessian Fly in Amer.
ica, because il was enormously supposed
to have been introduced in straw with the
Hessan troops during he war. The
same, or is not the same, q similar insect
has also appeared in England, and spread
horror among the farmers. Often I'll late
10 the season wheat seems to be IN excel
lent condition, but about the month OF
May the ears will begin 10 hang down,
and the stems to bend, and soon patches
will appear in different parts OF the fields,
which are probably oil a poorer soil than
The others, with the plants en,sngei and
matted together, as though lodged by
heavy rains. This singular appearance
would at IRIS. be supposed to be the effect
OF high winds; but 1t will be found to
spread in fine calm warm days, from the
poor soils TO those richer. and finally 10
the best land, thus biightIng our iairest
hopes. More than two.tnrds OF the straw
is often lodged in less than week, ard
heavy rains will then often complete the
work of destruction, so that wheat fields
will appear as if herds of cattle had gone
over them.
The cause of damage, if sought for,
will soon be discovered, as at the crown
of The root Of each OF the wheat plants, or
at the first JOIN; within the sheai Of the
leaf, whole clusters OF pupe OF this insect
are found. Those plants, The roots OF
which are attacked, die off; and the spot
to which the insects fasten themselves on
the still sof. straw within the shcaf OF the
leaf will be found TO be brown, witheIed
and tough, yet without any apparent
wound. The straw which becomes lodg-
ed produces small ears, with few and i'm
perfect grains. which rIpen with difficulty
aud are of very inferior quality. The
largest OF the insects are about The length
of two lines. Their color is pale green,
with a small black dot above. Some,
generally the strongest individuals, pene-
trate high into the tube ofihe straw, which
they rob of the sap rising up IRON the roots.
The straw in consequence becomes dry
at the first joint, and falls over or leans
on It's neighbor. The upper part OF the
straw receives its nourishment from the
atmosphere alone, and the ears form, but
they will continue 10 sickly condition,
and can only produce small shrivelled
grams. The life of the caterpillar APP
pears 10 be from about "a to 80 days
AS the straw rpens the insects change
their color into brownish hue, shrlvel
up. and finally disappear. II has not
been observed that these insectswere most
abundant in any particular situation or
disposition Of the ground. They appear
in as great numbers on elevated ground
as IN those fields that lie low; and are
not more numerous in those having a
southern exposure than in those that open
to the north. Neither has a rich or Tess
copious manuring any influence on them.
When the pupa case is opened i is ca
SLY observed, partly from the form Of the
pupa, and partly from the unchanged cat.
erplIEer in the pupa state, that IS a small
fly. 1t is extremely tender and small, aud
is scarcely the size of a common mosquito,
Its body is covered with sho.t blach hairs.
The ,horax or throat is much aished, smooth
and SHINING. The scutellum projecting,
rounded posieriorIy, the breast sometimes
golden yellow; the abdomen brown'sh;
the wings blackish; the golden yellow OF
the base is continued sometimes TO the
veins, where it appears lighter, and olssp-
pears by degrees about the middle. The
halteres are yellowsh white the logs
golden yellow at he base Of the thigh.
The female has black streak on the abb
domen. The larva is, according 10 Say,
spindle shaped and whiiish; the posierior
end suddenly diminished the head bent
inwards, and transparent above. A short
green line is remarked within, which is
the intestinal canal. Ii is dirty white be-
low; in younger >pecimens this coloring
appears like une spots on each side, and
has row Of still smaller spots in the mid
die. Whom TIE larva are fully grown,
they unite ia regular cross segments
round the wheat they are then provided
with very small hooks or notches towards
the head, when taken fromthe straw they
are immovable. Their .engih IS three.
twentieths Of an inch. The pupa, or RAJ
Their The pupa case, resembles the full
grown larva, but II is dark reddish brown,
and entirely withou, motion. The perfect
insect appears in May or June; The female
laws her egg from oneto eight 10 number,
IN the autumn, by means OF an ovlposi,or
between the sheaf or the leaf nearest the
root OF the stem, where the Dung lalvs,
as soon as they are Matched, find their
nourishment. Here the larva are said to
pass tho winter with their heads turned
downwards. The injury which these IN
sects occasion, is Of course not observed
till the wheat has grown higher.
The natural enemy of this wheat fly,
is an ichneumon. like insect, still smaller