1 84 The Control of Mosquitoes 



and a very low fever rate. These instances in 

 which fish alone have not proved satisfactory are 

 not intended to give the impression that fish are 

 of small service in combating mosquitoes, but to 

 show that on the Isthmus recently developed 

 methods of control are more swiftly effective than 

 nature's methods of more limited control. Fish 

 are most useful under many conditions, but the 

 places in the tropics where their control reaches 

 perfection are limited. Undoubtedly if all fish 

 were removed the number of adult mosquitoes 

 including Anopheles might become so great as 

 to be unbearable and many places wotild be 

 uninhabitable. 



We believe that the introduction of the proper 

 species of top feeding minnows into lakes and 

 large ponds would be of decided advantage for 

 purposes of mosquito control in cotmtries less 

 favorable to mosquito propagation than Panama, 

 and that the introduction of fish should be accom- 

 plished and the species selected with care, after 

 consultation with those competent to give advice 

 regarding fish propagation. 



Probably in the near future artificial control of 

 mosquito propagation by means of top feeding 

 minnows will be used extensively. Many miles of 

 drainage ditches on the seacoast meadows of the 



