The Bridgeport evening farmer., 1916-01-14

Specialists of the U. S. Department
| OF ~ sricultlre are urging cattle own
ers, in tie North as we'll as in the
South, to take steps to tId their cat
| lie of OK MARBLES or 'twol"ce'', the i'm
! portancte Of which to the, cattle in
dustry has been gene ally urderesti
| mated. o.. MARBLES ;Iro the wllitieh
grGbs pIaegots when develop from
the eggs deposited by certain flies
/ know as MARBLE flies or heel tiles
! and which injure tn, hides. reduce
milk flow aad retar~ the growth OF.
monty found just below the skin on
the backs of cattle, in the spring.
Their presence is revealed by local
swellings about the size of pigeons
eggs, each with small central hole
or perforation through which the.
maggot breaths. From this hole the
maggot, when mature, energies to en-
ter the ground and change to the
adult or fly stage. When full grown
the grub is about three-fOurthS of an
inch in length.
In the past trouble from the war
bles has largely been confined to cat,
/ tie in the South, but recently the
Bureau Of Entomology has discovered
that a second Species heretofore not
found in this country but known to
be even a more serious pest, in Eu-
rope, than is our native MARBLE, has
become well established in certain
districts in the northern part of the
United States While it is probable
that this so-ca1Ied European OK war
Bile will not be of as great import
ance in the Southern part of the
United States as the species already
established. there is Veery reason to
believe that unless checked it will
become generally distributed through
out the northern half of the country.
This European species is now gener-
ally distributed throughout New York
and the New England states, and a
few specimens have been obtained
from western Pennsylvania, western
Maryland, southern Michigan, east
ern Iowa and Missouri, and western
Washington. Attention is also direct
ed to the fact that this species is now
generally distributed throughout
southern Canada. The Department,
therefore, is calling attention at this
time to the danger of spreading this
species promiscuously about the coun-
try. and is urging cattle owners to
take the simple means necessary to
prevent its spread
Marbles Damage Hides, Reduce Milk
Production and Retard Growth.
Until recently MARBLES were not re-
garded as serious even in the South,
because it was thought that the loss
they occasioned came principally from
the damage they did to hides Even
this loss in the aggregate, however, is
important, as hides show MARBLE holes
three to six months in the year and
dealers pay from SO cents to $50
less for hides that show even moder-
ate MARBLE infestation. In many cases
the scars left after the holes have
healed cause buyers to cut prices
considerably.
The loss from the MARBLE, however,
is by no means limited to the holes
the maggots cut in the hides Extern
sive Investigations in Germany and
Denmark indicate that the losses
through reduction milk supply in
dairy cattle, the retardation of growth
in young stock, and the loss of flesh
in all classes of animals are tWo-fold
greater than the damage done to the
hides. In some of these tests the
early extraction of the grubs from
the backs Of infested cattle resulted
in an increase of nearly % per cent.
in the milk production. Animals |
from which the grubs had been ex-
tracted showed a gain of more than
; per cent in weight over similar an
inals in which the pests were allow
ed to develop normally.
Methods OF Controlling Marbles
Thus far the veterinarians and en-
tomologists of the Department have
determined no better way of control1- |
ing these pests than through the sys-
tematic extraction and destruction of /
the grubs from the backs of infested /
animals. t
When the larvae are nearly ready /
to leave their host they may be easily I
squeezed out by pressing the swelling
with the fingers but if not SO far de-
veloped it is often very difficult to
get them out by squeezing. In such
cases a slender pair of forceps may /
be used for pulling them out. If the
swelling and its opening are still very
small the best way of extracting the I
grub is to make an incision with a
knife after which the grub can be
out by applying strong pres
sure. Kill the grub when removed
When to Examine Cattle
It is important that MARBLES be re-
moved as early in their development
as posi- BILE. This relieves the tnfest-
ed animals from the irritation and
prevents the enlargement of the exit
holes. While this practice is not ap-
plicab1e to ranch conditions it is easily
put into effect on small farms and inl
dairies. In the Southern States the i
herds should be gone over early in
December and about twice later at.
intervals. In the Northern
States the extraction should be be-
gun six weeks to two months later.
If no grubs are allowed to drop to
the ground and reach maturity the
NJ ~