Vermont farmer. [volume] (Newport, Orleans County, Vt.) 1870-1877, 1874-01-23
Parasitic Insects Of DOnees-
tic animals,
And thor Destruction.
A Paper read at the Farmers Meeting OF
the Board OF Agriculture, &C., by DIR. II.
A. Cutting, of Lunenburgh, state GeolO-
gist.
iConclnded.l

tconotudedJ
Another variety of bot fly, Estrus boris
having very hairy body, with large head,
yelowish face, brown eyes, and black anten-
nae with wings Of smoky brown, lays its eggs
on the backs of cattle, mostly on younger
ones They seem apprehensive Of trouble
when the fly approaches, and if possible will
get into water and as it is one Of the pecu-
liariiies of this fly never to fly over water,
the creatures are there perfectly protected.
Where those flies are abundant, as in some
parts of Europe, the cattle will be perfectly
furious running or gadding away, as they
call il, which peculiar actions Of the cattle
led people to call it the 'gad Ay."
In this country, the fly or perfect insect
appears during the summer season, from
June to September, and the females, after
pairing, lay their eggs in the hair, near the
skin, on the backs of the cattle. The eggs
soon produce larvae which eat their way in
to the skin Of the animal and quite through
into its flesh, where they remain during the
winter.
After entering in this manner they gradu.
ally increase in size, in their burrows, eating,
and in fact, living upon the pus formed by
the inflammation their presence excites. In
this way they produce assesses under the
skin, their burrows running directly down.
ward with the posterior portion Of the body,
in which their breathing spiracles are stuat-
cd near the opening, so as to obtain the nee
essary amount Of air. The mouth is situat-
ed at the lower end of the insect, and is fur
nished with minute suckers, by means Of
which it sucks in the food upon which it
lives, aud with which it is surrounded.
1t is when nearly full grown in the spring
Of the year that they are most commonly no.
ticed At this time they can easily be re-
moved by squeezing the flesh surrounding
them. They will be found more frequently
upon yearlings than upon any other cattle.
Their color when young is nearly whito, but
darker as they advance in age. When full
grown, which is late in the spring, they work
themselves out of their burrows backward,
enarging the hole little by little every day
until they get out, when they fall to the
ground, and change in day or two to the
pupa state, their dried up skin forming a
black cover, or pupa case. In this case, i'm
bedded slightly in the EARTH they remain in
the dormant state from six to ten weeks,
when the top Of the case comes of and full
grown perfect fly comes forth, ready to de-
post its eggs as before stated. Farmers
generally think that this hot is no real in
jury, and do not much regard it, but it is
quite otherwise.
The presence of few larvae will do little
or no harm, but many times the creatures
suffer to such an extent that they will be.
come poor, lose their appetite, and finally
die. The skin will be removed, hundreds Of
holes upon the back will show what is be.
meath yet the farmer will remark at is
!, always So" and believe some other disease
caused the creatures death, overlooking the
4 real cause. Some kill the maggot, or wor'
A nil, by inserting hot wire but they can b.
A as quickly squeezed out and much more safe
o ly, or their deposit can be prevented by to-
\ bacoo wash, or any puugent smelling powder
In fact it is stated that little brushing
;. even once in two or three days, while thu
flies are about, will fully prevent the trouble
4 Another fly of this species, Gstrus gas
4" terophitus eQii, has large head, light yel
n low face and legs, antenne rust colored, alb
domcn Of reddish yellow with black spots
!. its wings whitish, having golden tint. II
# deposits its eggs upon the hair Of the horse
y and they are productive of the bots in horses
but it is hardly yet settled whether it is o
+ any disadvantage to the horse. There ar
q many books however that consider the bot
a in horses grave affair, often producing sick
ID ness and death, yet it seems that scentiii
examination has shown few facts, viz
4. that the bot never gnaws or eats the horse
h. stomach until after the horse is dead. Tha
ne it subsists upon the juices of the stomac
v. alone, and though large number nigh
cause indigestion, to a certain extent, as
10 general thing it is more nearly Harmless
TO than any other parasite. Mr. Bracy Clarl
whose careful and laborious investigation
to entite his opinion t. great respect, believe
is the effect Of bots to be healthy rather thu
otherwise
70 The female fly in approaching the horse ft
lis thepurpose oflaying its eggs, carries her bod
Id nearly upright in the air, the Protrudcd ov
nd postor, or egg-tube, being curved inwar
be aud upward Suspending herself for ie
seconds before the part Of the horse on while
nd she intends to deposit the egg, she suddenl
he darts upon it and leaves the egg adhering
the hair she hardly appears to settle, b.
Il merely touches the hair with the egg hel
no out on the extreme point of the oyposito
the egg adhering by means Of glutno
~ liquor with which it is covered, She thu
on leaves the horse at small distance prepar
second egg and posing herself before Il
1t part, deposits it in the same way. The
quOr dries, and the egg becomes firmly glue
to the hair. This is repeated until four
,n- five hundred eggs are sometimes placed {
ere one horse The skin of the horse is usual
thrown into tremulous motion on the tou'
Ic- of the insect, which merely arises from 4
nd very great irritability of the skin and cuta
eous muscles at this season Of the year, occ
led stoned by the heat and continual teasing
the flies, till at length these muscles appe
N act involuntarilv IN the SLIGHTEST ton