221 



reduction of the mosquito plague during the summer month.s, 

 is the application of kerosiue to restricted and Ashless breeding 

 ponds. On the 5th of July of the present year (1892) I noticed 

 for the first time a few mosciuitoes on the porch of my 



cottage One of the surface pools mentioned 



was situated upon my own groinids, and upon fii-st noticing 

 the mosquitoes I walked out to this spot. It was about dusk 

 and a dozen or more female mosquitoes were found buzzing about 

 the surface of the water. I immediately sprinkled four ounces 

 of coal oil upon the sur-face of the pond. Upon the following 

 day I measured the little pool and found it contained sixty 

 squai'e feet. '' 



'' The actual good accomplished is shown by the following 

 facts : All aquatic larvai, including those of the mosquito were 

 killed. The kerosine, curiously enough, seemed to exercise no 

 deterrent effect upon the adult female mosquitoes. They still 

 continued to attempt to deposit eggs and in this attempt were 

 destroyed. This is, in my opinion a most important point, and 

 one which has hardly been anticipated. — On the tenth day 

 after the application a careful count of the dead insects floating 

 upon the surface of the water was made over a restricted 

 portion, and from this count the entire insect surface contents 

 was estimated, with the following result. Entire number of 

 dead insects floating on the surface 7,400 ; number of mosquitoes 

 370. The observation, it seems to me, possesses interest not 

 only as proving definitely the efficacy of the remedy and as 

 showing that adult mosquitoes are killed as well at their early 

 stages, but also as affbi-ding an indication as to the amount of 

 kerosine, which will prove effective for a given surface of water 

 and also as affoi'ding some indication of the length of time 

 for which a single application will be operative. It is true 

 that upon this last point the observations were not complete, 

 owing to my departure after ten days, but as already indicated, 

 the influence of the kerosine outlasted all ocular or odorous 

 evidence of its presence, and there is every reason to suppose that 

 it would have continued for at least some days longer .... 

 The economy of the operation is shown by a simple estimate 

 from the data which I have given, that five gallons of coal 



oil will treat 9,600 square feet of water surface 



With this remedy and with the drainage of swami^ lands where 

 practicable, with the introduction of fish into ponds in which 

 they do not already occur, and with the careful watching of rain 

 water barrels and tanks, the mos(juito plague in many localities 

 can be readily and greatly lessened. Where mosquitoes breed, 

 however, in a long succession of brackish mai'shes on the sea coast, 

 remedial work is practically hopeless." 



