SANITARY ENTOMOLOGY 



CHAPTER I 



How Insects Can Carry or Cause Disease ^ 

 W. Dwight Pierce 



Our nation, as well as all our world civilization, is facing the greatest 

 crisis in its existence in these days of reconstruction. We must con- 

 serve human energy and keep it at its greatest possible point of effi- 

 ciency. This means above all that questions of health are foremost 

 today. 



Entomology bears a twofold relationship to health. Adequate food 

 supply upon which human and animal health are contingent is dependent 

 to a greater or less degree upon insect depredations. This is the side of 

 entomology which has in the past received most of the recognition, that 

 is, agricultural entomology. It has been generally recognized that insects 

 also bear a direct relationship to health, but the public has more or less 

 discounted the relationship, with the result that our public appropria- 

 tions for the study of insects affecting crops are approximately thirty 

 times as great as the appropriations for the study of insects affecting 

 the health of man and animals. The present course of lectures aims to 

 give the latest views in this almost unworked field of medical entomology, 

 with a view toward demonstrating the necessity of obtaining a better 

 balance in the two great phases of economic entomology. 



The scope of the course embraces studies of the relationship of 

 insects to disease, the life history of the insects which cause disease, 

 and the best methods of prevention of disease causation by insects. It 

 is intended to be placed in the hands of the men who will conduct work 

 along these lines, to show them why insects are dangerous, how they are 

 dangerous, what their habits disclose as weak points subject to attack, 

 and finally, how to go about controlling them. 



In my opinion the near future will see a group of professional sanitary 

 entomologists whose services will be available to solve the insect prob- 



* This lecture was given on May :^0, 1918, and mimeographed copies were dis- 

 tributed May 22. It has been considerably revised for the present course. 



19 



