The citizen. (Frederick City, Md.) 1895-1923, 1915-04-16
SIMPLE TRAP FOR HOUsE-FLY
Will Practically Prevent Breeding OF
This Summer Pest.

This Summer Pest.
A maggot trap which will practl-
cally prevent the breeding OF the
house-fy is described in a new bulle-
tin of the U. S. Department of Agr-l
culture, No. 200, "A Maggot Trap In
Practical Use; An Experiment In
House-F'Iy Control" The invest1ga-
tors who carried on this experiment
at the Maryland Agricultural College
declare that during August and Sep
TENDER at least SO per cent OF the
larvae breeding in the manure were
destroyed, and although the trap was
not so efficient when the weather BE-
came colder, even then it greatly re
duced the number of flies.
The principle of the trap is simple,
it is easily to construct, and expense
is said to be probably less in the long
run than the investment which many
farmers now make in screens for their
dwellings, and sprays and fy-nets for
their live stock. In its toughest out
lines the trap consists of a concrete
basin with a latticed wooden platform
erected upon it to hold the manure.
The basin is connected by a drain pipe
with a small concrete cistern. The
bottom of the basin is filled with wa
ter into which the maggots breeding
in the manure drop, as they are about
to turn in the pupa or chrysal1s
stage, and are drowned. At frequent
intervals the water is run off into
the cistern and is then pumped back
on the manure pile. In this way all
the liquid manure is saved.
The successful operation Of this trap
rests upon several facts connected
with the habits Of the house-fy which
have been thoroughly established by
observation. The adult fly lays its
eggs in fresh manure. There they
remain until the larva stage is al
most over and the insects are about
to enter the pupa or chrysalis stage.
At this time a pronounced tendency
TO migrate is evident. In consequence
if the manure is placed upon plat
form with latticework bottom the
larvae, while migrating. will fall
through these openings into the wa
ter in the basin below. In the case
OF the experiments at the Maryland
Agricultural College a careful count
showed that between July 25 and Oc-
tober ! about IL, 900 larvae were kill
ed in this way. This, however, does
not include the number that were
picked up from the basin by sparrows
or poultry. Altogether it is estimated
that during the warm weather the eff
cheney Of the trap was probably SO
per cent Later, when the tempera
Jure was lower, the traps success
was not so marked This was &C
counted for by the fact that when the
air is much colder than the manure
heap the larvae Will not attempt =
leave the heap and therefore will moi
1all into the basin
Another difficulty experienced arose
from mosquitoes using the water in
the basin and the cistern to breed in
This was overcome by cleaning out
the basin al regular intervals and by
SpTiDkling little oil over the sur
face Of the water in the cistern.
Properly constructed, such q trap
offers no obstacles 10 the convenient
| and economical handling Of manure
Il is essential, however, that each
days addition to the heap should be
sprinkled with sufficient water ito
keep the manure moist but not enough
TO cause teaching. The details Of the
construction Of the trap are contain
ed in the bulletin already mentioned
This particular trap was designed TO
hold the manure produced by three
horses for three months. but there is
no reason why larger quantities
should moi be treated in the same
way. by building larger traps or by
building several OF smaller size.