16 ASSOCIATION OF ECONOMIC ENTOMOLOGISTS. 



thorough, even if to accomplish this it is necessary to confine atten- 

 tion to a single insect. A nucleus of exact knowledge will later 

 attract about it other knowledge of the same and different sorts, and 

 thorough training, though brief, will greatl}^ help to this end. 



ENTOMOLOGY AND HUMAN DISEASES. 



I come now to a consideration of a feature of our subject that has 

 only recently assumed prominence. The relation of insects to diseases 

 is a very interesting and important one, and one to which entomolo- 

 gists should devote more attention. Some excellent work relating to 

 species and life histories has recently been published, but I would be 

 glad to claim for my fellow-workers more of the credit for the dis- 

 covery of the relation borne by mosquitoes to yellow fever and other 

 diseases. No investigator is better equipped than the entomologist 

 for such investigation. There is opportunity yet for valuable work 

 in this field, and entomologists should at least cultivate all the terri- 

 tory on their side of the line dividing entomology from medicine. It 

 should not be said of us that men who have had no training in our 

 specialty must come over into our domain and collect for themselves 

 entomological information which we have neglected. Tliis is eco- 

 nomic entomology, if ever there was any, and we should demonstrate 

 that we are able to furnish to the world all the facts along tlie line 

 that may be required. In teaching the subject, too, this relation of 

 insects must receive due attention. 



The fact recently demonstrated, that the mosquito /Sfef/omijia fas- 

 c?'«i«Fab. [^calo pus M.Qig.'] conveys yellow^ fever, and that therefore the 

 disease can only occur as an epidemic within the limits of the distribu- 

 tion of this insect, is one of the most important made known by the 

 study of epidemic diseases in recent years. This mosquito is known 

 to occur throughout the world between the latitudes 39° north and 

 about 37° or 38° south. In this connection it may be remarked 

 that the yellow-fever mosquito occurs throughout most of Kentucky, 

 and that yellow-fever cases originated in Louisville in 1878 to the 

 number of 20. I am informed b}^ the city health officer that the 

 seven cases treated at the Lexington hospital during the fall of 

 1005 were all refugees from Louisiana. The facts now known with 

 reference to this insect and its relation to yellow fever show in a 

 very lucid way the reason for the delving for seemingly unrelated 

 knowledge practiced by many entomologists. Herein is the justi- 

 fication of the devotee of pure science. The facts unearthed by him 

 concerning the structure of the beak or stomach of a mosquito, with- 

 out a thought beyond adding this knowledge to the common stock, 

 may prove, when all is known, to have a very important bearing on 

 the welfare of human kind. 



