Facts About the Fly by H. C. MENKEL, M. D.

Review and Herald Publishing Association · Takoma Park Station, Washington, D. C. · May 15, 1913

Facts About the Fly

By H. C. MENKEL, M. D.

H. C. MENKEL, M. D.

With the return of warm weather there is also the return of the fly, now recognized by man as his worst enemy in the insect kingdom.

The Fly the Product of Filth

The female lays her eggs preferably upon horse manure, as this seems to be its favorite larval food. It also breeds in human excrement. In the absence of these, it will oviposit in drains, garbage cans, ash-pits, rubbish heaps, and other offensive matter. Herein is its great danger to human beings, for it carries the germs of disease from human and animal excreta to the food supply.

The number of eggs laid by an individual fly at one time is very large,—from one hundred twenty to one hundred fifty,—and a single fly may lay four such batches during the hot season. The eggs hatch in about eight hours, then follow the larval stage of five days and the pupal period of five days, thus making the total developing period about ten days. This makes it possible for the production of eight to ten generations every summer.

The disease-bearing possibilities of the house-fly are most apparent—from the manure pile, the latrine, privy vault, consumptive’s sputum, or decaying matter, it sails gaily through the open window, alighting on the dining-table, and leaves filth on whatever it touches.

The microscope shows that the leg of the fly is covered with stiff bristles, like the head of ripened wheat. The germ-laden filth sticks to these bristles, and is shaken off into the food as the fly trails over it. By actual count it has been found that one fly may leave thirty thousand germs in its tracks.

In another experiment four hundred fourteen flies were examined after being allowed to walk through a culture of typhoid fever germs. Each fly was then placed in a bottle of sterile water and washed by shaking the bottle. The germs in the water were counted, showing how many each fly could carry on its body. The count ranged from five hundred fifty to over six million.

This is exactly what happens when the fly falls into the milk or other fluid foods, and struggles about in the endeavor to free itself. The germs are washed from its body into the milk, which thus becomes a liquid culture of disease germs.

The secretary of the Colorado Board of Health tells of a typhoid epidemic traced to the above cause. “A farmer’s wife had typhoid; the bowel waste was deposited in an open vault within thirty-five feet of the milk-house. The bacilli were carried from this vault by flies, and deposited upon the utensils in the milk-house. This dairyman supplied one hundred forty-two families. Among them occurred fifty-five cases of typhoid fever, from which six deaths resulted.”

In New York City diarrhea carries away about seven thousand infants annually. The infection is conveyed to these babies by the fly. Through the cities of our land there is each year during the fly season a veritable slaughter of the innocents. Enough has been discovered to indict the fly as the most dangerous creature to man. Keep it out of your house as you would a deadly snake.

For several years a “swat-the-fly” educational campaign was conducted with good results. This year we are to have a new slogan, “Starve the fly,” which promises even better results. The only way of combating this insect is to destroy the breeding-places. All refuse should be kept in closed receptacles and taken away from the premises at frequent intervals. No offensive matter must be allowed to remain longer than five days in order to prevent breeding. Manure piles should be screened and have added to them daily a shovelful of chlorid of lime. Make use of disinfectants freely to prevent breeding. Kerosene and chlorid of lime are the best.

To kill the fly a weak solution of formaldehyde gives excellent results. The proportions are two teaspoonfuls of a forty-per-cent solution to a pint of water. Place this where the flies have easy access, and they will drink and fall dead. Kill the fly, prevent his breeding, and screen your houses, your food, and your baby’s bed.

Only an energetic cooperation on the part of all can rid our land of this pest. What has been done with the malaria-breeding mosquito in Cuba and Panama, can be done with the fly in America. Do your part, and do it well.