MENACE OF THE HOUSE-FLY.

New Zealand Herald, Volume LVIII, Issue 17780, 13 May 1921, Page 6

MENACE OF THE HOUSE-FLY.

FROM STABLE TO SUGAR BASTN.

A terrible indictment of the house-fly was the most striking portion of a. lecture on sanitation given by SurgeonGeneral McGavin, in Wellington, this week. In detailing the "abominable habits of this filthy beast," Dr. McGavin traced the life history of the fly, from the hatching in stable refuse, which was chosen because of its natural warmth and its prompt supply of food for the larvaa and the young fly, and then explained roughly the insect's anatomical structure. Its proboscis led to a stomach and also to a large " crop" which held several days' supply of food, which it filled at suitable opportunities. As the only digestive glands were the salivary glands, the fly could digest carbo-hydrates (starches, sugars), but not proteins (such as meat). It had, therefore, to get its proteins in a pre-digested form, and got them in latrines and other filthy places. It got starch and 6ugar in the kitchen and the dining room, and visited the places alternately. To moisten the sugar and other soluble dry foods it used some of the! liquid proteid food from its crop, with the certain result of contaminating the human food on which it fed; and there were in a fly's "crop" many of disease germs. " People sometimes say the fly is clean because it cleans its feet and legs. So it does; you can anv day, especially on sugar basins. But what we should concern ourselves with is not the cleanliness of the fly, but what it does with the dirt it gets off. The very fact that a fly cleans its feet is proof that thei'e is something on them that even a fly will not tolerate!" Dr. McGavin referred to the fewness of the natural enemies of the fly, and their relative inefficiency. Ths flybrejLso fast that one female will produce in a few generations an unimaginable number of progeny, so that by killing even a single, fly 6no performed a duty to the State.