50 PLAN OF CAMPAIGN AGAINST THE MOSQUITO 



Those accustomed to take part in anti-malarial and 

 anti-yellow fever operations are accustomed to hear 

 many objections against doing any tiling. Some will 

 argue, what is the good of trying to do such an im- 

 possible task as exterminating mosquitos ? The people 

 who argue thus are generally those who live in large 

 swampy countries and in countries about or below sea- 

 level, where there is always a great abundance of water 

 and very frequently enormous numbers of mosquitos. 

 The answer to these objectors is that in the first place 

 the war is against one particular group of mosquito, 

 the anophelines, which are, moreover, very selective 

 breeders and not found in the middle of lagoons and 

 rivers but only along the margins. In the second 

 place, that as lagoons, canals, large trenches, rivers, 

 and deep marshes are usually plentifully stocked with 

 fish, larv£e are not present. For example, Barbados 

 is an island which appears to be entirely free from 

 anophelines, yet scattered tln-oughout the island there 

 are numerous ponds ; these are, however, plenti- 

 fully stocked with minute fish, and so no larva? can 

 exist. 



The very first thing, therefore, to be done in an 

 anti-malarial war is to make an accurate survey under 

 the guidance of an entomologist in order to accurateJy 

 locate the breeding places of the enemy, and thus to 

 avoid dissipating energy by attacking useless places, and 

 by so doing anticipate defeat. A mosquito survey is 

 tlierefore first made, and it is surprising when this is 

 done how comparatively localised will the breeding- 

 places be found to be. Others will argue that the 



