HEALTH NOTES

Nelson Evening Mail, Volume LXI, 29 October 1928, Page 8

HEALTH NOTES

THE HOUSE FLY

DISEASE CARRIER

METHODS OF CONTROL

(Contributed by the Department of

(Health.)

With the advent of summer must be considered that most common of all household pests, the housefly, its life, cycle, habits, methods of control, and relationship to disease. This insect is undoubtedly the commonest and must widely-spread of all insects; and when ily-control methods are not carried out there is a great upward rise in the curve of its prevalence during warm summer weather.

The structure of the fly is familiar tii all. It has .one .pair of wings.' 'file front of.the head is occupied • almost entirely by a pair of large, compound eyes. Eacli of these compound eyes is composed of about four thousand faceted individual eyes, and so the insect is provided with a wide range of vision. The head also carries the "proboscis,” or, as it is familiarly cajlcd, the tongue. This proboscis represents the very much modified mouth parts of jaws o*f other insects, and is wholly adapted to sucking. The common housefly cannot bite. Other varieties of flies, such as the stable fly, do and can bite, and their mouth parts are modified accordingly. When not feeding and in a stuto of rest, the. proboscis is carried bent up in the inside of the lower part ot the head, but when the fly alights oil food the proboscis or “tongue” is protruded. It has a thorax or chest, abdomen, and three pairs of legs. The terminal .segnieiit of the legs are so constructed that the fly can crawl on very smooth surfaces.- and can progress- without difficulty in an upside-down position along ceilings. They are extremely prolific. The adult female lays eggs, and will deposit about 100 to 120 at each laying, and will repeat the performance about four to six . times in one season, so that one female fly may lav anything up to 680 or-so eggs in one season. These eggs are usually deposited in positions that •are favourable to their development-. The site most commonly chosen is in horse manure but-the eggs may be.deposited in any decaying matter. thus the eggs may lie deposited on decaying vegetables, decaying fruit, meal, human and Quintal excreta of all descriptions. The eggs are pearly-white in colour. In suitable conditions as to temperature a lid moisture, these eggs limy batch, out in Froiti eight to twenty-four hours into definite larval stage, but in unfavourable surroundings the hatchings may require four days.

HABITS The fly- is a, constant guest , at- our tables, sipping the milk, tasting the sugar, and next minute may be tickling its palate with a. tasty morsel from a nearby ash-tin or stable. It may be feeding on the most indescribable filth, and next-moment he buzzing round the kitchen. Flies are always most numerous where filth abounds, and the number of flies present is in some measure a criterion of the sanitary conditions. Good, sanitation implies an .absence of breeding-grounds, and an absence of exposed food, and so implies a minimum of flies. SPREAD DISEASE

Flies iii;iv spread disease-jn mure than one way. The germs of disease may adhere to'the body or legs of the fly and may be deposited on its nest resting place. Tims disease germs may bo carried direct. They may also absorb disease germs in their food, and these germs may live some considerable dime bi the alimentary tract of the flv. These germs may then be deposited on its next resting place - either by regurgitalioli or vomiting, or in its excreta.. So it is not. to be wondered at that flies are injplii’ated in the sorcad of, diseases like typhoid fever, epidemic diarrhoea, dysentery, etc. It is considered that flies may spread the infection in summer of epidemic diarrhoea, which is such a serious disease in children. CONTROL METHODS The presence of the house liy in our dwellings is pitch subjected to as an irritating but ail inevitable nuisance; yen many certain remedial measures weuki aiiuost exlehmuate this insect. j.iio nrst essential oi control is to remove tee possible breeding giouiids, and lu control .adequately those that ciiuuui be linineuiaieiy removed. Accumulations ut desaying vegetables, aatv paper, kitchen atid table retusu should Jiot be allowed tu remain about u.e premises. All sanitary arrangements sjiuUiil Iju kept clUciii 9 and tlie kuuschulu pi ivy lilted with a ligllt.ly-litting' llyjii'oPi lul. Horse and . cow manure should, be frequently swept tip and deposited m a manure bin protected front mes by a suitable lid. rfuch manure should be removed,at least once a week, ami btuied hi the garden or held. Another method pi preventing the breeding oi hies in manure is oi spraying With such a solution - as coal-tar, sheep ilip, or with an emulsion of crude tar on anil soap. Stables and cow-slicds should be kept clean, all manure being removed at teast twice a day. In the home no lood should be exposed to tbe attacks of Hies, and every endeavour should be made to kill.them by the use of fly-traps,, sticky, papers, etc. A .Useful solution is to aud an ounce of formalin to a. phit of water and milk, and expose in dishes .about the rooms. Remember —Hies spread disease. By carrying into persistent practice that well-known slogan,' ‘Swat that Hy, much can be done to reduce danger to bea'iLi from this source. All foodstuffs in the home or exposed tor sale should be protected from contamination' iroin [lies. Remember that flics spend most of tlicir lives in a very circumscribed area, so 'that if pestered with' them it is probable that tlie breeding ground is near at band, and should be sought lor and'dealt with efficiently.