USE OF FISHES FOR CONTROL OF MOSQUITOES IN NORTHERN 

 FRESH WATERS OF THE UNITED STATES/ 



By J. Percy Moore, University of Peniiftt/lvania, Temporary Investigator, U. S. 



Bureau of Fisheries. 



CONTENTS. 



Page. 



Introduction 1 



Some aspects of the mosquito problem 2 



Biological factors in the natural control of mosquitoes 3 



Methods and i*esults of investigations on fishes 7 



Roach or golden shiner {Abramis crysoleucas) 10 



Goldfish (Cnrassius auratus) 14 



Mud minnow {Umhra pygmwa) 15 



Common killifish (Fundulus heterocHtus) 2.3 



Translucent killifish (Fundulus diaphanus) 28 



Top minnow (Gambusia afflnis) 31 



Blue-spotted siinfishes (Enneacanthus gloriosus and E. obesus) 36 



Long-eared sunfish (Lepomis auritus) 40 



Common sunfish (Eupomotis gibbosus) 40 



Some general conclusions and considerations bearing upon the use of 



fishes to combat mosquitoes 53 



Summary 58 



Literature cited : • 59 



INTRODUCTION. 



At the outset of our participation in tlie World AVar a demand 

 arose for the suppression of malaria and mosquitoes, especially with 

 a view to improving the healthfulness of cantonments and increasing 

 the efficiency of workers in war industries. The Bureau of Fisheries 

 was early called upon to cooperate, and its correspondence of that 

 period included many requests for advice on the employment of 

 fishes as destroyers of mosquito larvae, especially in waters to 

 Avhich the engineering solution of drainage could not be satisfacto- 

 rily applied. In the South this phase of antimosquito work was bet- 

 ter understood and the remedy rather extensively applied. The mos- 

 quito-eating habits of the top minnow (Gambusia) were well known 

 and tested, and especially under the able direction of S. F. Hilde- 

 brand this little fish has been very successfully employed. In the 

 North fishes have been little utilized hitherto in the actual work of 

 combating mosquitoes in fresh waters, though the killifishes (Fun- 

 dulus) are well known as destroyers of the salt-marsh species. 



The writer having volunteered for war service was, therefore,' 

 in the spring of 1918 assigned the problem of determining what 

 species of fishes in northern fresh waters were mosquito destroyers 

 and what the conditions of their utilization were. At his request the 



* Appendix IV to the Report of the U. S. Commissioner of Fisheries for 1922. B. F. 

 Doc. No. 923. 



