The Grenada sentinel. [volume] (Grenada, Miss.) 1868-1955, 1912-06-14
The Horn Fly On Cattle

l..
During the late spring and early
of each year W. receive many
inquiries for remedies against the horn
fly. During very dry seasons this pest
does not often become numerous, but
often after a week or two of wet wea-
Their they are quite serious. Few peo-
pie know how to control this pest. and
fewer still know anything in regard to
its life history, The horn fly, like many
of our serious pests, is an introduced
1t is not a native Of America,
and was unknown to this country pre-
vious to 1887. It has long been a cat
tie pest of Europe. In 1887, the flies
were first noticed in and around Phila-
delphia, Pa. BY 1891 they had reached
Mississippi. They have now been 10
years in this state and are probably to
be found wherever there are cattle.
There are many exaggerated ideas in
regard to the injury caused by these in
sects. They injure stock by irritating
and worrying them. This causes a de-
crease in milk flow, falling off in weight
and a general loss in vitality. Because
people See the flies in immense num-
bers on the horns Of cattle it has been
thought that the horns are injured by
the maggots boring through and enter
ing the heads of the animals. This is
not true, for as long as the flies are on
the horns they are not injuring the an
finals. AZ.
Life History: There are many false
ideas az to where the flies originate.
This much has been found out by nu-
merous careful investigators. The eggs
are laid in fresh cow dung. They are
deposited within a few minutes after
the dung is dropped. 1t takes less than
one day for the egg to hatch, and in
about two weeks from the time the
eggs are deposited the adult flies begin
to emerge. The eggs hatch into tiny
maggots. These maggots feed upon
the manur until they r about LIZ
inch long and then go into the ground
to pupate, that is. to pass the quies-
cent stage. They remain about one
week as maggots and about one week
in the ground as pupae. They then
come out as full grown flies, ready to
bother cattle, to mate, and to lay eggs
for another generation. As only two
weeks are required to complete an.
other generation, it is easy to see how
there can be as many az a dozen gener.
ations each year in a climate such al
we have in this state.
Remedies: Numerous remedies have
been used and recommended by people
handling cattle as well as by entomolo
gists, but as IAN ounce of prevention
is worth a pound of cure" perhaps the
most satisfactory manner of destroying
the insects is to destroy the maggpts il
the COW dung. The eggs are usually
laid during the hottest part of the day
and it is at this time that the cattle
usually congregate in some shady par
of the pasture. A shovelfull Of lime
will destroy the maggots. This is of
ten not practical, but in small pastures,
or where cattle are kept in lots, it doei
not require much labor. Another ever
cheaper method of reaching the same
result, is to spread the manure out il
the hot sur at once 50 that it will dry
out. This prevents the maggots from
maturing. These remedies are especi'
ally useful in the early part of the sum
mer, for by their use the number o.
flies can be greatly reduced SO that il
midsummer they will not be 80 nu
merous.
When the flies appear in large mum
bers, the best method of combating
them is to apply repellapts externally
to the animals. A repellant is som.
substance that is SO distasteful to tn,
flies that they will not come neal it
and at the same time it must not b,
injurious to the stock. Many sub
stances have been used, but only twt
of the most satisfactory ones will b,
mentioned here. l, A mixture of tw,
parts of crude ~cottonseed oil and on,
part of pine tar. This should be ap
piled to the animals with a large pain
brush. 1t can be done best at milking
time if dairy cattle are to be treated
Fish oil may be used instead Of cotton
seed oil. One application will las
about five days. 2, Another prepare
ton that is applied in the same name
as the tar and oil is made as follows
One ounce of crude carbolic acid, 8.
ounce of pennyroyal, IA pound sulphu
and l gallon crude c~ottonseed oil.