834 BULIvETIN OF THE BUREAU OF FISHERIES. 



dollars have since been spent in the attempt to destroy the breeding places, 

 they are no doubt still occupied, within gunshot of the stately Fifth avenue 

 homes and nearer to the beautiful playgrounds of the park. The same con- 

 ditions will be found to prevail in every city. 



The most prolific source of Anopheles supply is the ornamental plant pond, 

 which is becoming one of the most beautiful features of landscape gardening, 

 public and private. These aquatic gardens provide Anopheles with habitats 

 closely approximating the conditions it enjoys in nature, with, however, many 

 protective advantages. Waters of this character can not be treated with oils 

 or chemicals without destroying their beauty. Thus it becomes a serious 

 problem how to destroy this pest and yet preserve the beauty of the ornamental 

 plant pond. 



Anopheles, as well as all other mosquitoes, have numerous enemies in 

 addition to fishes. All the aquatic beetles and their larvae (and they are 

 numerous), the dragon flies and their larvse, the boat flies, the crane flies and 

 their larvae (and where these latter are numerous few mosquito larvae will be 

 found), the water skaters, and many others. 



The use of fishes for the purpose of destroying mosquito larvae is looked 

 upon generally as an easy solution of the problem, and numbers of species have 

 been recommended for the purpose, but so far as Anopheles is concerned the 

 fishes have been generally useless. It is true that by their presence in the more 

 open spaces they limit the areas in which mosquitoes would otherwise propagate 

 in great numbers, and no doubt they destroy some Anopheles, as well as some 

 of all other species of mosquitoes. 



All small fishes, whether of the smaller species or the yoimg of the larger 

 kinds, will be found to eat mosquito lan.^se with avidity if supplied to them. 

 This fact alone can not be taken as evidence of usefulness in this respect in a 

 natural condition. Nevertheless, there is no doubt that the myriads of small 

 fishes everywhere on the salt marshes and as well in all open waters, salt and 

 fresh, prevent by their presence such a multiplication of mosquitoes as would 

 make life unendurable. In this respect even the most insignificant of the fishes 

 are useful and merit our gratitude. 



In considering the usefulness of fishes in this relation the natural habits 

 and characteristics of a species are the only safe guides. That they will eat 

 mosquito larvse if confined in an aquarium is to be expected. But will they 

 do so in a natural condition? Will they seek for them as food? Stagnant 

 water, where there is an abimdance of plant life, affords such a great abundance 

 and variety of larvae and other low forms of animal life that fishes could hardly 

 be expected to develop epictorean tastes for particular kinds of larvae. They 

 appear rather to gorge themselves with whatever comes in their way. The 



