The Bureau of Entomology for a number of years has advised that manure
from horse stables be kept in fly-tight pits or bins. Such pits can be
built in or attached to the stable so that manure can be easily thrown
in at the time of cleaning and so constructed that the manure can be
readily removed. It is desirable that the manure be placed in these
fly-proof receptacles as soon as possible after it is voided. The
essential point is that flies be prevented from reaching the manure, and
for this reason the pit or bin must be tightly constructed, preferably
of concrete, and the lid kept closed except when the manure is being
thrown in or removed. The difficulty has been that manure often becomes
infested before it is put into the container, and flies frequently breed
out before it is emptied and often escape through the cracks. To obviate
these difficulties a manure box or pit with a modified tent trap or cone
trap attached is desirable.
In order to retain the fertilizing value of manure to the greatest
extent it is advisable that air be excluded from it as much as possible
and that it be protected from the leaching action of rains. This being
the case, there is really no necessity for covering a large portion of
the top of the box with a trap, but merely to have holes large enough to
attract flies to the light, and to cover these holes with ordinary
conical traps, with the legs cut off, so, that the bottoms of the traps
will fit closely to the box. The same arrangement can be made where
manure is kept in a pit. If manure boxes or pits are kept fly tight they
are satisfactory under farm or dairy conditions for the storage of
manure during the busy season when it can not be hauled out daily.