CAJV THE MOSQUITO PEST BE MITIGATED? 683 



Tliese are tlie conditions in nature. But the attempts to sub- 

 ject dragon-fly life to the rules of art do not appear to have been 

 successful. Mr. Weeks tried earnestly and most intelligently to 

 raise the insects artificially on his father's farm on Long Island 

 and in his house in Brooklyn, and failed to obtain any results 

 worth boasting about. He finds that they are diurnal, working 

 in the sun, and never present at night, when the mosquitoes are 

 busiest; that they are short-lived, and frequently destroyed in 

 large numbers by heavy showers and winds ; that, with few ex- 

 ceptions, they confine themselves to the vicinity of their place of 

 birth, and, if removed therefrom, quickly return — hence, can not 

 be colonized ; and he concludes that " an attempt to destroy flies 

 and mosquitoes by the artificial propagation of dragon-flies or 

 any other insect would be unprofitable, unadvisable, and imprac- 

 ticable." 



Mr. Beutenmuller thinks that positive statements can not 

 yet be made respecting the expediency of artificially breeding 

 dragon-flies for use against the mosquito. Differences in the 

 habits of the two insects are against the scheme. Dragon-flies 

 seek open places and the sun, while the mosquito finds hiding- 

 places in the woods and in tall grass. " Under these circum- 

 stances the dragon-fly will not find its prey. Great numbers will 

 escape ; only those encountered in its busy flight through the air 

 will be captured, for the dragon-fly does not hunt for its booty 

 nor scour the forbidden shadows of woods and forests, and at 

 nightfall the mosquito will elude his pursuer and rise to his 

 murderous intent." But the dragon-fly "may, in some genial 

 locations, suit the elements of the question and be of practical 

 service ; it may, indeed, be more widely beneficial than we sus- 

 pect." 



Of other means of keeping down mosquitoes, Mrs. Aaron 

 recommends flushing the breeding-places with water, draining 

 swamps, creating active artificial currents, encouraging fish, and 

 spraying their hiding-places with petroleum. Mr. Weeks has 

 faith in the enforcement and observance of sanitary laws and the 

 encouragement of birds. Mr. Beutenmuller advises the use of 

 lanterns so arranged as to attract and destroy the mosquitoes, 

 with pans of kerosene or other strong mixtures for their destruc- 

 tion, which may be placed around houses and hotels and in 

 marshes, general and scientific drainage of swamps ; encourage- 

 ment of fish and waterfowl ; and, where the conditions are favor- 

 able, the use of coal-oil in the waters of estuaries of rivers and on 

 the rain-invaded areas of deep woods for destruction in the larval 

 stages. Astringents, like logwood or alum, will also prevent the 

 growth of the mosquito in its incipient stages. Dr. H. C. McCook 

 thinks it might be well to call spiders into service. 



