Yerington times. [volume] (Yerington, Nev.) 1907-1932, 1914-06-27
ENORMOUS LOSS CAUSED BY
BOT FLIES.
Millions of Dollars Damage to Hides
and Beef.

Between thirtyhve and fifty million
dollars damage to hides and beef is
our annual toll to bot flies, with cat
tie, according to H. f. SEVERN, Pro-
lessor of Entomology at the South
Dakota State College He says: THE
'grubs weaken the cattle, cause them
to fall off in flesh and milk, and de-
crease the value of the hide. The
beef in the immediate vicinity of the
grub becomes moist, and of a green
ish yellow color-and is consequently
known as licked beef"
Now is the time to examine the cat
tie for bot fiies-also known as heel
flies and OK MARBLES. In late winter
or early sring, pass the hand over the
backs of the stock, observing the To-
cation of MARBLES by swellings By ex-
erting pressure on these the grubs
may be forced out OF the skin entire
ly-or partially-and in the latter case
they may be removed with tweezers.
The grubs may also be killed by
forcing oil or grease into the opening
of the skin, but this is less certain
than removing the bots, and has the
further objection that the dead larvae
remain beneath the skin The use
of repellants to keep the mature
flies from laying their eggs on cattle
is thought to be of little value. The
most practical method is to remove
the grubs from the cattle-all the
farmers in a locality working together
to remove the pest Cooperation is
necessary.
A description of the heel-hy of cat
tle-or bot fy-with its life history,
is outlined by Professor SEVERN as
follows:
"The heel-hy is winged in
sect resembling somewhat a common
honey bee in appearance. The flies
are on the wing during the summer
months, and glue their eggs to the
hair of cattle, fastening them usually
to the hair Immediately above the
hoofs. Although the flies can neither
bite nor sting, stock are driven into
frenzy by them, and often dash into
shrubbery or into water to avoid
them. The excitement of cattle at
such times is very similar to that
shown by horses whenever these ami
mails are pestered by chin flies 1t
seems that the bot fies do not ap-
proach stock standing in or over wa
ter and il is no uncommon sight to
see cattle remaining in water for the
greater part OF the day when flies are
abundant.
Either the eggs or the maggots
are carried into the mouths of the
cattle as they lick themselves. In the
former case, the eggs hatch in the
mouth or food tube. In either case,
however, the 'grubs' migrate into the
oesophagus and penetrate its walls,
and from there the larvae work their
way into the muscles, etc, of the neck
and body and finally lodge under the
skin of the back. Here they cut a
hole through the hide and it is through
this hole that the grubs' breathe and
later leave their host
During the time that the larvae is
within the body of the cattle, it is
continually feeding upon the mucus,
pus and blood which collects about its
body By spring the 'grubs are full
grown, and their location may be de
termined by the more or less conspic
uous Jumps which they form. At this
time the feshy larvae are about an
inch long, and of yellowishwhite
color. They now force their way out
of the skin through the hole men
toned above, drop to the ground, and
burrow into it for a short distance
Here they change to blackinsh pupae,
which, in turn, at the end of three
TO six weeks, give rise to adult flies"
-Y-
Kind Word for the Crow.