CHAPTER XII 



ATTACK ON PROPAGATION AREAS AND ADULT 

 MOSQUITOES BY NATURAL ENEMIES 



PROPAGATION AREAS 



OMALL top-feeding fish which prefer to obtain 

 *^ their food at or near the water surface are 

 of great value in reducing the number of mosquito 

 larvse that would otherwise pupate. It was 

 frequently observed that they seemed to prefer 

 the full-grown larvae and pupae. Many different 

 kinds of these fish are found in all parts of the 

 Isthmus, in rivers, streams, and drainage ditches 

 connected with them. On the arrival of the dry 

 season they were often left stranded in small 

 puddles and died as these became dry. While 

 fish remain in small bodies of water they greatly 

 assist in reducing mosquito possibilities, but if the 

 water in the pool contains much green algse the 

 small fish destroy only a portion of the larvae. 

 Where larvae can hide easily, fish catch the fewest. 



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