THE HOUSE FLY.

New Zealand Herald, Volume XLIX, Issue 1514, 9 November 1912, Page 1 (Supplement)

THE HOUSE FLY.

it ARBAOES,

Muse A domestic* is the Latin name of that well-known anarchist, the oommon house fly. . It belongs to a laTge and widelyscattered family known as tho diptera, or winged insects. For a part of the year it lives in every home from Alaska to Cathay; but, clearly, it is under no government of its fellows. The ant, with patient care in the cause of order, has established an efficient police, and an unwritten constitution which, 'for the purposes of good government, might cause the despair of a Roman jurist. The bee ia always garnering, and, undeterred by the spoiler, lie is always searching for fresh treasures. But the house fly has. come down the centuries in no wise hindered by the cares of life; the empty travel free, and it has neither storehouse nor barn. Buskin accuses it of irreverence : tho seeming " irreverence" is the strict impartiality we find everywhere in Nature.

I The jura common a. of Nature are more ! universal than our social laws?—the house fly is as much at home in a king's palace as it is in a peasant's cot, for it is no respecter of persons. From its first origin — the fermenting filth in which it is hatched and throughout the scope of its after activities—tho life round the house fly has been closely studied in recent years. It has been followed everywhere with the microscope, and it now stands unmasked as one of the worst enemies of mankind : an enemy moro universal than famine and more unrelenting than war. It is difficult to rouse public interest in a campaign against house flies. Dr. Howard, of the United States Department of Agriculture, at the meeting of the American Association for the Advancement of Science, held at Baltimore, proposed a change of name to typhoid fly for the purpose of educating public opinion and of sounding an alarm. It is true that people will fear and fight a typhoid fly where they would regard a house fly with in- ' difference. The indifference is surprising because the fact that house flies are dis-ease-carriers is a part of the knowledge not of our day alone, but of all the days.

The Greeks and the Romans knew that flies were the- heralds of disease. In Exodas.we axe told that/ " there came a grievous swarm of flies into the house of Pharaoh, and into his servants' houses." Clearly, it was an unhealthy season in Egypt, and we remember the significant sequel—the murrain of cattle and the death of the first-born. In the 6anitary regulations of the camps of Israel in the wilderness there were by-laws against flies necessary when we remember the rat© at which they multiply. An egg of the house fly is hatched in eight hours, the duration of larval life ia five days, fox- five days longer it lives as a pupa in a cylindrical case,' which is formed when the larvce shrinks from its own skin; from this case, which pupa opens with the pressure of an inflated bag, the fly emerges on the tenth day fully equipped for its mission of mischief. About 120 eggs aTe laid at a time, a generation is renewed in 10 days,, and there are 10 generations every summer. The; totals would become uncanny. Flies lay their eggs in tainted dust and ferment-, ing vegetable matter, but, if given their choico, they always prefer stable refuse. It is estimated that 90 per cent, of the flies that invade our houses *vre bred in stables, and it may readily happen that the flies in a given neighbourhood come from the same source. Mr. Newstead, lecturer on economic entomology at the University of Liverpool, found that the female house fly will lay her eggs on any fermenting organio refuse, such as spent hops or barley malt, kitchen refuse, paper, sacking, straw, etc., and that the larv® will feed upon textile fabrics, such as woollen and cotton garments, if they are kept, warm and moist. The rate of increase is taken from Dr. Howard's estimate for th© city of Washington, a low estimate for Auckland, because hard frosts kill many millions of eggs and larvae at Washington, while our flies multiply throughout the year. Mr. Jepson, research (jcholar in entomology at the University of Cambridge, found that even in the English winter house flies multiply and prosper exceedingly if they are fed in arti-ficirJly-warmed places. The house fly is distinguished for strength and activity, and is capable of flying long distances; its flight is remarkable for steadiness both in progression and when it changes its planes of flight. At the suggestion of Professor Langley,. of the Smithsonian Institute, Mr. W. Wright, the American aviator, built his successful biplane on the construction principle of the house fly : the principle of keeping the weights well below the plane of the wings. Professor VanvLendenfeld, of Prague, who has closely studied the flights of birds and insects, is of the opinion that of all flying creatures the diptera—-two-winged insects supply the best models for flying machines. Like the bee, the house fly has a colour preference. An interesting series of experiments were carried out by Mons. Galli-Vellerio in connection with the French Department of Agriculture in 1910. Th© observations with regard to colour preference were made in a movable glass box, so arranged that like conditions of light and heat could be secured everywhere; on its walla pieces of paper were pasted similar in size, Ibut differing in colour. He found that flies prefer clear green, rose, clear yellow, and azure; they avoid blue, violet, and dark brown.

The ant has been an example to the sluggard for centuries, and wo all agree that puss is sly : Shall we agree that the house fly is persistent? Invincible persistence is the most distinctive feature in the character of the house fly. Drive it away; it moves, but only to prospect the butter; it soon returns to the same spot unabashed. On a ■warm day in summer the habits of the house fly may convincingly be studied in the dining-rooms of many country hotels with windows open to the stable yard. It is a creature of one quality—persistence— and of one idea — Unfortunately it is mainly in connection with our food that flies cause unmeasured mischief as carriers of disease. Every summer a largo number of young children suffer acutely from the effects of the contamination of their | food by house flies. We learn from ob- | servers everywhere that flies carry opthalmia, typhoid fever, tubercle, summer complaint" cholera of infants, anthrax, boils, etc. The only way of dealing efficiently with the fly nuisance is to destroy the fly hatcheries, and, as stables aw the largest j incubators, they should not be built near closely-populated areas. In many parts of Auckland, notably in the Mbunt Eden district, there are stables that remain a danger to the public health. After stables, come our own yards; the kitchen pail, the dust-bin, and the line of the back fence. Beware of house flies. " Carry the whole fight outdoors, where it belongs," says Professor Clifton F. Hodge, Professor of Biology at the Clark University, Worcester, who (succeeded in destroying 16,000,000 flies with the assistance of a few Worcester school children in a thre? weeks' campaign. This effort was part of his idea to bring vital science , into the lives of the people by way of the public schools. A blase friend loitering in the lanes of life wants to know the us© of the house fly in the general plan. Who knows? Happy the man of simple faith who can believe with the shepherds of Egypt and the Far East that some things were sent to us for blessings and some things for oar chastisement by the Great Power behind the universe, who set the courses of the planets, made Venus to be the Shepherd s star, and bade Sinus guide their caxjiYJU}? across the- iracklesfl jxaata*, * a