THE HOUSE FLY OR TYPHOID FLY
In the house fly we find one of man's most deadly foes. War can not
compare with the campaigns of disease and death waged by this most
filthy of all insects. In our recent strife with Spain we lost a few
lives in battle, but we lost many more in hospitals due to contagious
diseases, in the transmission of which this pest played a most important
part.
The fly is dangerous on account of its filthy habits. It breeds in
filth, feeds on filth in open closets, slop-barrels, on the streets and
in back alleys and then comes into the house and wipes this germ-laden
filth on our food or on the hands or even in the mouths of helpless
babies. Who has not seen flies feeding on running sores on animals, or
on "spit" on sidewalks? These same flies the next minute may be feeding
on fruits or other food materials. We rebel when pests destroy our crops
or attack our stock, but here we have a pest which endangers our very
lives, and the lives of those dear to us.
If the fly confined itself to filth we could overlook it as it would
help to hasten the removal of filth. On the other hand, if it avoided
filth and remained in our home we could not overlook it, but we could
feel safe that it was not apt to do us a great deal of harm. But, like
the English sparrow, one minute it is here and the next somewhere else;
from filth to foods and then back again to filth. In this way it carries
disease germs upon its feet and other parts of its body and by coming in
contact with food material some of these germs are sure to be left on it
and cause trouble later. The fly's method of carrying disease is
different from that of the mosquito where the germ is carried inside its
body.
[Illustration: House fly; a, larva or maggot; b, pupa; c, adult; e, egg.
All enlarged. (Modified from Howard Bur. of Entomology. U. S. Dept.
Agri.)]
The presence of flies in the home is usually a sign of untidiness; but
it means more, it means that disease and often death is hovering over
the home. We are too apt to consider the fly simply as a nuisance when
we should take it more seriously. The child should be led to realize
that the fly should not be tolerated in the home, that it is dangerous
and that it can and must be destroyed.
The house fly may pass the winter either as the adult fly in cracks and
crannies about the home, or in out-buildings or it may remain as a
hard, brown, oval pupa in stables and manure piles when, with the first
warm days of spring, it escape from this case as the fly ready to lay
eggs for the first colony. The fly breeds largely in horse manure either
in stables, manure piles or in street gutters where manure is allowed to
collect. Each female lays a large number of eggs and since it requires
less than two weeks for the pest to mature, we are soon overrun with
flies in the summer where steps are not taken to control them. The
maggots are often so abundant in stables that they can be scooped out
with a shovel. This ceaseless breeding continues from spring until the
first frost in the fall.
[Illustration: Favorite breeding places of house fly. Such places should
be kept as clean and neat as the front yard.]
In the control of the fly and prevention of trouble from it there are
three important steps to take. First of all, go to the source of the
trouble and do away with or screen all breeding places. Then, by keeping
in mind the fact that the fly is comparatively harmless as long as it is
kept from filth laden with germs, do away with all open closets,
uncovered slop-barrels and other filth. As a further precaution keep it
from the home by the use of screens and when necessary "swatters." Do
not make the mistake of trying to control the pest with the "swatters"
alone. In the country too often manure is permitted to accumulate about
the barn during the summer with a view of using it on wheat ground in
the fall and this furnishes ideal conditions for the fly to breed.
Another source of constant danger especially in the rural districts is
the presence of open closets or worse still the presence of no closet at
all. This is without doubt the most dangerous accessory of the farm.
More screens should be used in the home and greater care in keeping them
closed.
[Illustration: An open closet to which the house fly has free access.
Such a closet is the most dangerous accessory of any home.]
STUDY OF THE FLY AND ITS WORK
Observe first of all the feeding habits of the fly. What foods in the
home is it most fond of? Make a list of all the food materials it is
found to feed on. Where and on what is it found feeding out doors? Do
you find it feeding on filth and if so, on what? Do you find it about
the barn? Where is it usually found in the barn? How can the fly carry
filth to food materials?
In studying the breeding of the fly determine where it lays its eggs and
where the maggots are found. Examine fresh manure in the stable and see
if you can find small white maggots about half an inch long and as large
around as the lead in a pencil. If you do, place some of them with some
fresh manure in a glass jar and see what becomes of them. In a few days
the maggots will disappear and in their places small oval, brown
bean-like objects will appear. A few days later these will crack open at
one end and the fly will crawl out. Keep records of the length of time
it requires for the pest to pass from one stage to the other. If maggots
cannot be gotten put some fresh manure in the jar and catch a number of
live house flies and put them in with the manure and watch for results.
Collect a jar of fresh manure with maggots and sift over it a little
powdered borax and see what happens to the maggots. Where horse manure
can not be properly disposed of, cheap borax is used to throw over piles
of manure to destroy the maggots and prevent the flies from breeding in
it. Write a brief description of the different stages and make careful
drawings of these. Do not mistake the house fly for other flies often
found on food in the home.
Collect a few flies and put them in a bottle and drop in with them just
a few crumbs of sugar and watch them feed. They cannot chew but a little
saliva from the mouth dissolves a little of the sugar which is then
lapped up as syrup. Notice what a peculiar sucker they have for drawing
up liquids. How can they crawl along in the bottle with their backs
toward the floor? Examine the tip of their feet for a small glue pad
which sticks to the glass. These glue pads and the sucker are well
fitted for carrying filth. Examine the fly carefully and write a brief
description of it. What color is it? How many legs? How many wings? Are
these transparent? Behind the wings there is a pair of small stubs which
is all that is left of the hind pair of wings. Are the eyes large? Can
you find a pair of small feelers? Why can you not pick up a fly like you
would a grasshopper? Is their eye sight good? Why are they always most
abundant on a kitchen screen door? Can they smell?
What are the fly's worst enemies? Will the toad eat them? Do chickens
eat them? Have you ever seen chickens scratching in manure and feeding
on the fly maggots? Put a few drops of formaldehyde, which you can get
from a druggist, in a few spoonfuls of sweet milk or sugar syrup and let
the flies eat it and see what happens to them. This is one of our best
poison baits for flies which get in the home or collect about the dairy.
Formaldehyde is a poison and when used in bait it must be kept out of
reach of children. Just about frost, in the fall, watch for the
appearance of inactive flies on walls, windows and other parts of the
house. These have been attacked by a parasitic disease. These are often
found sticking to walls and other objects about the room in the winter,
and are commonly thought to be passing the winter.
* * * * *
"_The insect we now call the 'house fly' should in the future be
termed the 'typhoid fly,' in order to call direct attention to the
danger of allowing it to continue to breed unchecked._"
--L. O. HOWARD.