Danger From Flies by F. C. RICHARDS

Review and Herald Publishing Association · Takoma Park Station, Washington, D. C. · Apr 21, 1910

Danger From Flies

By F. C. RICHARDS

F. C. RICHARDS, M. D., C. M.

The fly has been with us since the visitation of the plagues upon Egypt in the days of Moses. No wonder we treat it with contempt! It is a contemptible creature, but by all means let us not ignore it, and so permit it to destroy us. Perhaps the fly would never have been regarded with indifference had the people always borne in mind what Moses left on record about flies: “The land was corrupted by reason of the swarm of flies,” he said. Nor had this been forgotten in King David’s day, for he writes in the seventy-eighth psalm: “He sent divers sorts of flies among them, which devoured them.” And Solomon well names these noisome insects “flies of death.” So the people who have been blessed with Bibles did not need to be ignorant all these ages of the destructive character of the common house-fly, the mosquito, the tsetse-fly, and various other insects which David’s “divers sorts of flies” may be understood to include.

How Flies Defile Food

The fly is admirably furnished for the defilement of fluid and food. Each of its six little feet is fitted with a gummy, hairy pad. This enables the fly to stick to glass, and it also causes many objectionable things over which the fly walks to stick to its feet. The legs and body of the fly are thickly studded with short, stiff hairs, which brush through filth one moment and through food the next. In short, it would be difficult to imagine a more successful distributor of disease than the common fly. Of 414 flies which were caught and carefully examined, none were found to be carrying less than 550 germs, while some were carrying as high as 6,600,000, the average for each fly being 1,222,570 germs. When a fly falls into milk or other food, that number of germs may be left in the food after the fly has been removed. And the disease germs left behind may be those which cause typhoid fever, Asiatic cholera, dysentery, cholera infantum, and other intestinal diseases.

Mrs. Fly’s Family

Where do all the flies come from? Let us start with one female fly, and we shall understand soon how it is that flies multiply with such rapidity. A single female fly lays from one hundred to one hundred fifty eggs — some say one thousand or more. Let us take the lowest estimate, one hundred, and let us base our computation on the assumption that only five full-grown female flies develop from the hundred eggs. This allows for a mortality of ninety per cent, and of the remaining ten per cent one half would probably be males. This first generation of five female flies would reach maturity in from ten to fifteen days, depending on weather conditions. From these five in another ten days would be produced twenty-five females; then 125; 625; 3,125; 15,625; 78,125; 390,625; in the ninth generation, 1,953,125 female flies. There would, of course, be an equal number of males, and not only nine but fourteen generations of flies might easily be produced in a single season.

Favorite Breeding-Places

Flies, like other higher insects, pass through four different stages before they are fully grown. These stages are known as the egg, the larva, the pupa, and the adult. The eggs are by choice deposited on horse manure, but if none is available, other kinds of manure or any kind of decaying animal or vegetable matter will answer. In a word, the fly breeds in filth, and comes from that filth to our food. Dr. L. O. Howard found in horse manure 1,200 house-flies to the pound.

How to Fight Flies

1. Destroy their breeding-places. Allow no filth or refuse of any kind to remain where flies can gain access to it. In London, manure can be kept no longer than forty-eight hours on any premises, and then only in covered tanks.

2. Shut flies out of garbage boxes and lavatories. Cover all discharges with dry earth, ashes, or quicklime. (Read Deut. 23: 12-14.) Another excellent way to dispose of filth is to burn it. (See Lev. 4: 11, 12.) Disinfectants as generally used are comparatively worthless.

3. Shut out the flies with screens. Every window and door from basement to garret should be screened in such a way as to shut out all insect pests.

4. Keep all food and drink away from flies. If flies have gained access to a dish left standing on the table, destroy the food; do not eat it. Should a fly fall into baby’s mug, it is cheaper to throw the milk away than to nurse the baby through “summer complaint” or some other diarrheal disorder which may easily be caused by the filth and germs washed from the fly by the milk.

5. To destroy a large number of flies in a room, close it tightly and sprinkle pyrethrum on a tin which has been heated sufficiently to give off a dense white smoke. This smoke is poisonous to flies, but harmless to man.

6. An excellent fly poison consists of formalin, three parts; milk, four parts; water, thirteen parts. Mix and pour in shallow trays which are put in places frequented by flies, but out of reach of animals and children.

Cooranbong, New South Wales.