CHAPTER XXVIII 



INSECTS INJURIOUS TO MAN AND TO THE HOUSEHOLD. 



MANY insects attack man, directly. Many others injure him 

 indirectly by destroying his property within his dwellings or by 

 annoying him by their presence even when they are not actually 

 destructive. Such insects represent many groups of the most 

 diverse habits. The study of some of the more serious of these 

 pests has, in comparatively recent years, been crystallized into 

 the science known as medical entomology and through much of the 

 widely advertised work pertaining to certain forms the public has 

 come to realize, as never before, the importance of recognizing 

 and controlling insects which were formerly tolerated. 



The Housefly* 



It is certainly safe to say that no insect is so well known as the 

 housefly. It is present in every part of the world inhabited by 

 civilized man and in most parts of the world which are capable 

 of sustaining life at all. While it has always received recognition 

 as a nuisance and a more or less filthy and repulsive object it is 

 only recently that it has been recognized as an actual menace to 

 the health of any community. The feeding habits of the adult 

 render it particularly dangerous in the carrying of disease germs. 

 It feeds alike on foods prepared for the table of man and on the 

 vilest forms of animal waste, excrement, sputum, pus and any 

 sort of decaying material. Most of these food materials of the 

 fly are particularly adapted for the propagation of bacteria and 

 many of such bacteria are disease-causing forms which may be 

 infective when taken with the food. It is for this reason that the 

 fly is particularly liable to be the agent for the transmission of 

 typhoid fever and other diseases which affect the digestive 

 tract. It is also quite capable of transmitting tuberculosis and 



* Musca domestica Linn. Family Muscidce. See bulletins from the 

 U. S. Dept. of Agr., and the State Experiment Stations. Titles too numerous 

 to be listed. 



635 



