Flies and Mosquitoes as Carriers of Disease 



By 

 William Paul Gerhard 



It is now well known that the common house fly and the mosquito are 

 not merely nuisances but enemies to mankind and positive dangers to 

 health by becoming at times the medium for disseminating disease germs. 

 We hear much of flies being the indirect cause of typhoid fever, and of 

 some species of mosquitoes causing malarial fever. Both typhoid fever 

 and malaria, though occurring to some extent in cities, are considered to be 

 chiefly country or farm diseases; hence this subject ought to interest the 

 farmer. 



It is not necessary for our purposes to explain at length how 

 diseases are transmitted by insects. Suffice it to mention that some insects, 

 like flies, carry disease mechanically by transferring the germs by means 

 of their bodies, wings and feet from human excreta to our food, while 

 others, like some species of mosquitoes, become the host of disease germs, 

 with which they inoculate human beings through their bite. It is now 

 firmly asserted that one species of the mosquito, the anopheles, is the only 

 contributing cause of malaria, and that this illness may be entirely avoided 

 by preventing persons from being bitten by infected mosquitoes of this 

 species. 



Taking the above statements as a basis, we wish to point out that on 

 many farms, in farmers' houses and about their barns, flies abound in 

 warm weather, while in other country localities the life of the occupants 

 of farm cottages is rendered miserable by the ravages of mosquitoes. 

 While both flies and mosquitoes are bad enough at certain times in the 

 city, they constitute in agricultural districts a veritable pest, a source of 

 annoyance to horses, cattle and men, a cause of physical discomfort, such 

 as loss of sleep, and a nuisance whereby health may become seriously af- 

 fected. Let us see, then, how far in rural districts the evil can be con- 

 trolled, and inquire what the farmer can do to assist in the crusade aiming 

 at their extermination. Let us study what conditions are met with in the 

 country and on the average farm, which favor the existence and breeding 

 of both flies and mosquitoes. Let us explain what remedial measures can 

 be readily applied by the farmer who anxiously seeks for improved sur- 

 roundings. 



Flies. 



1 



house fly," as 



s. 



The investigations of entomologists have shown that the "malevolent 

 5e fly," as Dr. Felt aptly calls it, breeds principally in horse manure, 



3 



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