The Prescott daily news., 1915-01-04
THE FLIGHT OF FLIES


 One of the problems that has arisen In connection with the part played bv insects as carriers of disease concerns the distance which they may be able to travel from one locality to another This has frequently been considered in this country in connection with mosquitoes which are responsible for the prevalence of malaria. With their breeding places known, it has become desirable in some cases to ascertain what the range of their activities might be in respect to the territory which can be covered by insects. It has been learned that mosouitoes which inhabit salt marshes near the seacoast may be found inland at a distance as great as three miles.
 Far less appears to be known with regard to the migrations of the com mon house-fy, an insect charged with responsibility for typhoid fever and other infectious diseases. A ser les of studies conducted in Cambridge England, on the range of the fight of flies of this species has been made the subject of report to the Local Government Board on Public Health and Medical Subjtces. Upward of 25,000 flies were liberated, under var ious meteorologic conditions, from the medical buildings at Cambridge. Of these insects, colored for identification 191 were recovered. The results show ed that house flies tend to travel either against or across the wind. The ac- tual dirction followed may be deter mined either directly and by the ac- tion of the wind, or indirectly owing to the flies being attracted by odors from food. A point in favor of this supposition is the nature of the sta tion at which flies were recovered af- ter they had travelled any distance These comprised butchers shop, pub- lie houses and a restaurant, all Of which gave off odors that are notor- iously attractive to flies. The chief conditions favoring the dispersal of flies are fine weather and warm temperature. The nature of the local ity is another considerable factor, be- cause in towns flies do not travel as far as in open country, probably due to the food and shelter afforded by the houses. With regard to the aIti- tude of the point of liberation, flies set free from the roof tended to dis perse slightly better than those lib- erated from the ground but the differ ences are not very considerable. It has been observed with regard to the vertical flight of the house-fy, that it may mount almost directly upward to a height of forty-five feet or more The time of day appears to influence the dispersal of the insects, as appar ently, when set free in the afternoon they do not scatter so well as when liberated in the morning.
 The maximum flight observed in the thickly housed localities in Cambridge was about quarter of a mile. In one case, where part of the distance was across open fenland, a flight of ITO yards was noted. In experiments con- ducted in Cook County, Illinois, by S.. A. Forbes, flies were trapped and, af- ter being sprayed with chemical so- lution for recognition, were liberated recovered at distances ranging up to a quarter of miles from the point ot liberation. The distance flies may tra- vel to reach dwellings is controlled by circumstances. Almost any reason able distance may be covered by the fly under compulsion to reach food and shelter.
 Strong Indian Characterization In