Belmont chronicle. [volume] (St. Clairsville, Ohio) 1855-1973, 1890-07-10
THE OK MARBLE OR BOT FLY
HOW IT OPERATES AS A PARASITE.
MODE OF TREATMENT

HOW IT OPERATES AS A PARASITE.
MODE OF TREATMENT.
Newspaper Bulletin of the Ohio Agricultural En-
pertinent Station.
In recent bulletin of the Ohio EX-
pertinent Station, Mr.. Clarence NJ. Weed
discusses the injuries and life of the Ok
Marble Fly or Bot Fly. He says that a
recent careful estimate from statistics
gathered by the Farmers ReoieoO, of
Chicago, Ills, indicates that Sc per cent.
of the cattle in Ohio are attacked by the
Ok Marble or Bot Fly (Hypoderma
bovis), and that the average loss ON the
hides due to the injuries of this insect
amounts to one-third their total value,
while the added loss due to the injury to
the beef for food amounts to an average
of 81 per animal. Statistics gathered
from ten of the principal stock-raising
States of the Mississippi Valley, showed
the lowest per cent. of infestation to be
thirty-three in Wisconsin, and the high
est seventy-three, in Illinois.
LIFE-HIsSORY OF THE FLY.
During the spring or early summer
one may often find along the middle of
the backs of cattle, just beneath the
skin, hard lump, usually having in the
center an opening, which sometimes is
more or less of running sore. These
are the warbleS," and the lump is caus-
ed by the presence of whitish or gray
ish maggot. Early in the summer these
maggots wiggie out of the warbles, tail
foremost, and fall to the ground, where,
under such protection as may be at hand,
they shorten for pupation, and soon
change to the pupa or chrysalis state
About month later they emerge as
adult flies, and the females deposit eggs
on the backs of cattle. The eggs hatch
into grubs that work their way into the
skin, where they form the warble cells
Their mouth parts irritate the flesh,
causing an liberation, which not only is
distressing to the animal, but Injuries
the hide and beef, and, in the case of
dairy animals, lessons the quantity of
milk produced.
The beef beneath these MARBLES has a
peculiar, diseased, sickening appearance,
and is commonly called clicked beef"
Such beef always commands a lower
price than that which is unaffected.
REMEDIES.
Every warble maggot destroyed in
spring before it escapes to the ground to
pupate means that one less fly will be
present to lay eggs for the coming brood
This should be carefully borne in mind,
for from it the conclusion is obvious
that if all the maggots now present in
the backs of the cattle of given neigh
borhood are killed, the egg laying brood
of flies will be exterminated and there |
will be no injury next season. There
is perhaps no other important injurious |
insect whose numbers can be so readily |
and the experience of English |
farmers, as published in Miss Ormerod's |
report, shows that by concerted action |
and continuation of the treatment the |
amount of warble attacks may be very
rapidly lessened.
Perhaps the simplest remedy to use
uuiihS SplLlS anu early SulllucI Is u |
squeeze the maggOt out of the warbles
When they are nearly fully grown this
can be done with little trouble; and when |
smaller the opening can be enlarged with |
a pen-knife so as to let them out. A |
pair of medium sized forceps are often
helpful in removing them.
Another simple remedy is to apply to
the opening little oil or grease, which
closes the breathing pores of the mag
got, thus causing it to die. Kerosene
applied to the MARBLES either in autumn,
winter or spring also destroys them, as
does indeed the application of almost |
any oily or fatty substance. DR.. C. V.
Riley says that smearing the animals
backs with this substance {" is the sim
plest and easiest method of destroying
the MARBLES, which it does by closing the
pores on the posteriOr end of
The body. The destruction of the larvae
in this way may be effected by one or
two applications in autumn, and is the
most satisfactory method of controlling
the pest