The Colorado statesman., 1914-04-11
TO DESTROY FLIES
Maggot Trap Possible Solution
of the Fly Problem.
United States Department of AsricuI-
ture Makes Successful Expert
ments That Should Be of In
terest to Health Officers.

WaSnlngton.-A trap to destroy the
maggots of the typhoid or housefy be-
fore they develop into winged insects
is possible solution of the fly prob
lem and one that should interest health
officers, sanitarians and others who
might make use of 1t on manure heaps
where this common pest breeds. The
department of agriculture's scientists
in their preliminary experiments with
such trap have succeeded in destroy
ing from 20 to 80 per cent of the mag
gots in pile of manure. This method
of attack differs from those which
have been generally used, Fly poisone
have been made to tempt the appetite
of the adult fly, or fly-tight receptacles
have been used to keep the adult fe-
male from laying her eggs in manure.
The newer method is based on the
knowledge of certain habits of the un-
developed fly maggot.
The maggots of the typhoid fly, it
has been discovered, have a habit of
migrating from their breeding places
into drier portions of the manure heap.
This seems a distinct move on their
part to permit the adult fly to issue
from the refuse in the easiest and
quickest manner. The efficiency of
the new trap is based on the regularity
of this deep-seated habit.
A large galvanized iron pan, measur-
ing five by three feet, with sides four
inches high, was made. In this stood
container on legs eight inches high.
This container measured four by two
by two feet The sides and bottom
were of heavy wire, one-fourth-inch
mesh, supported by a light wooden
framework. Twelve cubic feet of
manure well infested with eggs and
larvae were placed in this container
and sprinkled with water. Water was
also poured into the pan below to the
depth of about one inch. Surrounding
and covering both pan and container
was a fly-tight inclosure made of
large cage, six by six by six feet. This
prevented further infestation of the
manure, and an arrangement of traps
at the top of the cage made it possible
to capture and keep q record of any
flies that might emerge. AT the time
for the emergence of flies the sides of
the cage were darkened with black
cloth in order to drive the flies into
the traps at the top. Each day the
maggots were collected from the pan
and counted, and each day the manure
in the container was sprinkled thor
oughly with water and the pan was
washed out and again partly filed with
water to drown the larvae which fell
into 1t.
The experiments of the departments
entomologists showed that from 9S to
SO per cent. of all the maggots in the
manure pile were destroyed, if the
manure was kept moist. From COM
paratively dry manure about seventy
per cent were destroyed.
These experiments, as yet, have
been tried only on a comparatively
small scale. The question Immediately
arises whether the trap which appears
so successful on a small scale can be
adapted to the handling of manure in
a practical way on large scale Every
consideration points to the probability
that it can and that 1t will afford IAN
additional weapon of great value"
However, the final verdict as to the
value of the maggot trap must wait
upon the solution of certain practical
problems. To point out some of these
here is to suggest lines for further in
vestigation.
Q) In the first place, there must be
determined what form, size and con-
struction of trap will give the best re-
suits. The answer to this will depend
largely on the particular conditions OBJ
tanning at any given stable, such as
the amount of manure produced daily,
the arrangements for drainage, etc s. 1t
will also depend ON the answer to the
following problems:
(2) How deeply may manure be
heaped in a trap without Interfering
with the migration? 1t will probably
be found that the depth will make lit
tie difference, provided that the
manure is kept moist, and provided
that avenues of escape are afforded at
the sides as well as at the bottom.
(3) How long must manure be kept
in maggot trap before it is entirely
free from larvae? This is a very i'm
portant question from a practical
standpoint, and one will find scant sug-
gestion as to the answer in the litera-
ture on the life history and habits.
The housefiy breeds preferably in
horse manure, but it has never been
determined just how long a given lot
of manure continues to be an attrac-
tive place for egg laying, nor for how
long a period fly larvae will continue
to appear in it. 1t is obvious that the
maggot trap would not be practical If
the infestation of the manure were
daily renewed for long time. Under
ordinary conditions the drying of the
surface of a heap of manure probably
limits the period of egg laying to the
first day or two of exposure. But in a