18 PRINCIPAL HOUSEHOLD INSECTS. 



their breeding places. In not every locality are these measures feasible, 

 but in many places there is absolutely no necessity for the mosquito 

 annoyance. The three main preventive measures are the draining of 

 breeding places, the introduction of small fish into Ashless breeding 

 places, and the treatment of such pools with kerosene. These are three 

 alternatives, any one of which will be efficacious, and anyone of which 

 may be used where there are reasons against the trial of the others. 



In 1892 the writer published the first account of extensive out of-doors 

 experiments to determine the actual effect upon the mosquitoes of a 

 thin layer of kerosene upon the surface of water in breeding pools and 

 the relative amount to be used. He showed the quantity of kerosene 

 necessary for a given water surface, anil demonstrated further that 

 not only are the larvae and pupae thereby destroyed almost immedi- 

 ately, but that the female mosquitoes are not deterred from attempt- 

 ing to oviposit upon the surface of the water, and that they are thus 

 destroyed in large numbers before their eggs are laid. He also showed 

 approximately the length of time for which one such treatment would 

 remain operative. ^No originality was claimed for the suggestion, but 

 only for the more or less exact experimentation. The writer himself, 

 as early as 1867, had found that kerosene would kill mosquito larvae, 

 and the same knowledge was probably put in practice, although without 

 publicity, in other parts of the country. In fact, Mr. H. E. Weed states 

 (Insect Life, Vol. VII, p. 212) that in the French quarter of Xew Orleans 

 it has been a common practice for many years to place kerosene in the 

 water tanks to lessen the numbers of mosquitoes in a given locality, 

 although he knew nothing that had been written to show that such was 

 the case, and he says: "In this age of advancement we can no longer 

 go by hearsay evidence." Suggestions as to the use of kerosene, and 

 even experiments on a water surface 10 inches square, showing that 

 the larvae could be killed by kerosene, were recorded by Mrs. 0. B. 

 Aaron in her Lamborn prize essay and published in the work entitled 

 " Dragon Flies versus Mosquitoes " (D. Appleton & Co., 1890). Mr. W. 

 Beutenmiiller also in the same work made the same suggestion. 



The quantity of kerosene to be practically used, as shown b} T the 

 writer's experiments, is approximately 1 ounce to 15 square feet of 

 water surface, and ordinarily the application need not be renewed for 

 one month. Since 1892 several demonstrations, on both a large and a 

 small scale, have been made. Two localities were rid of the mosquito 

 plague under the supervision of the writer by the use of kerosene 

 alone. Mr. Weed, in the article above mentioned, states that he rid 

 the college campus of the Mississippi Agricultural College of mosquitoes 

 by the treatment with kerosene of eleven large water tanks. Dr. John 

 B. Smith has recorded, though without details, success with this remedy 

 in two cases on Long Island (Insect Life, Vol. VI, p. 91). Prof. J. H. 

 Comstock tells the writer that a similar series of experiments, with 

 perfectly satisfactory results, was carried out by Mr. Vernon L. Kel- 

 logg on the campus of Stanford University, at Palo Alto, Cal. In this 



