REPORT OF THE STATE ENTOMOLOGIST I908 ^'J 



a harmless species which, in recent years, has become well estab- 

 lished in many houses in New York State. It is credited with 

 preying- on house Hies, cockroaches and presumably other insect 

 inhabitants of dwellincfs. 



The house fly as a carrier of disease. The house fly is such 

 2 common insect that altogether too much has been taken for 

 granted. Up to recently it has been considered simply as an 

 inevitable nuisance. Later developments have shown that this 

 insect may be an important factor in the dissemination of certain 

 diseases. 



Typhoid fever is one of the most serious ailments to which man 

 is subject. There are about 250,000 cases of this disease annually 

 in America, about 35,000 proving fatal, (x/^ of the deaths in 

 the Franco-Prussian War and 2P';, of the deaths in the Boer War 

 were caused by this disease. Positive statements have been made 

 to the effect that the house fly was an active agent in the dissemi- 

 nation of this disease, while certain reputable physicians consider 

 this charge unproved. The Spanish- American War, if it accom- 

 plished nothing else, called attention in a most forcible manner to 

 the part flies might play in the dissemination of typhoid bacilli. 

 Dr yi. A. \'eeder of Lyons writing in 1898 was very strongly >of 

 the opinion that the house fly was larg-ely responsible for the dis- 

 semination of this disease in camps. Dr Walter Reed writing of 

 an outbreak near Porto Principe in the annual report of the War 

 Department states that the outbreak " was clearly not due to water 

 infection but was transferred from the infected stools of patients 

 to the food by means of flies, the conditions being especially favor- 

 able for this manner of dissemination." Dr L. O. Howard, writing 

 in 1900 on the fauna of human excrement, quotes from 

 Dr Vaughan, a member of the army typhoid commission, as fol- 

 lows: 



2"/ Flies undoubtedly served as carriers of the infection. 



My reasons for believing that flies were active in the dissemi- 

 nation of typhoid may be stated as follows : 



a Flies swarmed over injected fecal matter in the pits and tiicn 

 visited and fed upon the food |irc]iared for the soldiers at the 

 mess tents. In some instances where lime had recently been 

 sprinkled over the contents of the pits, flies w-ith their feet whit- 

 ened with lime were seen walking over the food. 



/' Officers whose mess tents were protected by means of screens 

 sufl'ered proportionately less from tyi)hoid fever than did those 

 whose tents were not so protected. 



