_The Survey_, in commenting on Dr. H. G. Beyer’s statement at a
recent conference of the New York Academy of Medicine that the fly is
“not merely a pest but an epidemic,” says:
One fly lays 120 eggs in the season, and as each of these eggs
takes but ten days to reach maturity, it has been computed
that twelve flies surviving the winter will produce 40,000 the
following summer. When to this estimate of numbers is added the
experimentally proved fact that one fly carries upon his legs
alone anywhere between one and six million bacteria, there seems
little exaggeration in Dr. Beyer’s characterization.
Observation has shown that the fly is omnivorous and ubiquitous,
and that, certain unsanitary conditions being fulfilled,
where-ever the fly is, there also are certain diseases. In
regard to these diseases the most startling evidence is given
for typhoid, but careful experiments have shown that no less
than ten others, among them tuberculosis, carbuncle, cholera,
tapeworm and summer diarrhea, have been spread by flies, and
there is good reason to believe that smallpox, leprosy and
diphtheria might be added to the list.
It is the omnivorousness of the fly, together with his choice of
breeding-places, that makes him a menace to health. A fruitful
source of disease bacteria is damp, decaying organic matter,
and it is just such matter, usually stable refuse, that is used
for a breeding-place by flies. Experiments with young flies
fresh from the breeding-ground showed them to have live bacteria
either on the outside of their bodies or in the digestive
tracts. This same decayed organic matter is also the food of the
fly, but with true democracy of taste he is glad to share man’s
food also, and it is this willingness to take his dessert out of
the sugar-bowl after a dinner of decayed fish that constitutes
his chief danger to man.
(2364)
=Pests=--See BARRIERS; PIRACY, BIRD; REMEDY FOR PESTS.
=Pests, Utilizing=--See INGENUITY.