The House Fly and How to Suppress It | Page 4

of one suffering from
tuberculosis), and that subsequently they may contaminate human
foods with their feet or excreta or vomit spots, the necessity and

importance of house-fly control is clear.
In army camps, in mining camps, and in great public works, where
large numbers of men are brought together for a longer or shorter time,
there is seldom the proper care of excreta, and the carriage of typhoid
germs from the latrines and privies to food by flies is common and
often results in epidemics of typhoid fever.
And such carriage of typhoid is by no means confined to great
temporary camps. In farmhouses in small communities, and even in
badly cared for portions of large cities, typhoid germs are carried from
excrement to food by flies, and the proper supervision and treatment of
the breeding places of the house fly become most important elements in
the prevention of typhoid.
In the same way other intestinal germ diseases, such as Asiatic cholera,
dysentery, enteritis (inflammation of the intestine), and infantile
diarrhea, are all so carried. There is strong circumstantial evidence also
that tuberculosis, anthrax, yaws, ophthalmia, smallpox, tropical sore,
and the eggs of parasitic worms may be and are carried in this way. In
the case of over 30 different disease organisms and parasitic worms,
actual laboratory proof exists, and where lacking is replaced by
circumstantial evidence amounting almost to certainty.

EXCLUDING AND CAPTURING FLIES.
The principal effort to control this dangerous insect must be made at
the source of supply--its breeding places. Absolute cleanliness and the
removal or destruction of anything in which flies may breed are
essential; and this is something that can be done even in cities. Perhaps
it can be done more easily in the cities than in villages, on account of
their greater police power and the lesser insistence on the rights of the
individual. Once people are educated to the danger and learn to find the
breeding places, the rest will be easy.
In spite of what has just been said, it is often necessary to catch or

otherwise destroy adult flies, or to protect food materials from
contamination and persons from annoyance or danger; hence the value
of fly papers and poisons, flytraps, and insect screens.
THE USE OF INSECT SCREENS.
A careful screening of windows and doors during the summer months,
with the supplementary use of sticky fly papers, is a protective measure
against house flies known to everyone. As regards screening, it is only
necessary here to emphasize the importance of keeping food supplies
screened or otherwise covered so that flies can gain no access to them.
This applies not only to homes but also to stores, restaurants, milk
shops, and the like. Screening, of course, will have no effect in
decreasing the number of flies, but at least it has the virtue of lessening
the danger of contamination of food.
Insect screens for doors and windows should be well made and must fit
tightly, otherwise they will not keep insects out. It is equally important
that they be made of good and durable screen cloth. Copper insect
screen cloth, although a little higher in price, will prove more
economical in the long run, as it lasts many years. If, however, the cost
of copper screen cloth is objectionable, steel screen cloth, either painted
or galvanized, can be used. Painted steel screen cloth will last one or
more years without repainting, its durability depending upon the
climate. In humid regions, of course, it will rust more quickly than it
will where the climate is dry. The same may be said of galvanized steel
insect screen cloth.
Insect screen cloth made with 16 meshes to the inch is recommended,
for 16-mesh screen cloth will keep out flies and most mosquitoes[9]
and other small insects which at times are found almost everywhere.
[Footnote 9: Where the yellow fever or dengue fever mosquito occurs,
18-mesh screen cloth (or 16-mesh screen cloth made from extra heavy
wire) should be used.]
FLY PAPERS AND POISONS.

[Illustration: FIG. 8.--Conical hoop flytrap side view. A, Hoops
forming frame at bottom. B, Hoops forming frame at top. C, Top of
trap made of barrel head. D, Strips around door. E, Door frame. F,
Screen on door. G, Buttons holding door. H, Screen on outside of trap.
I, Strips on side of trap between hoops. J, Tips of these strips projecting
to form legs. K, Cone. L, United edges of screen forming cone. M,
Aperture at apex of cone. (Bishopp.)]
The use of sticky fly papers to destroy flies that have gained access to
houses is well known. Fly-poison preparations also are common. Many
of the commercial fly poisons contain arsenic, and their use in the
household is attended with considerable danger, especially to children.
This danger is less with the use