DIPTERA. 29 
by hand into little cones about the size and shape of a large chocolate drop. These 
cones are then placed in a pan and thoroughly dried in an oven. When fired at the 
apex such a cone will smolder slowly and send up a thin column of pungent smoke 
not hurtful to man, but stupyfying to mosquitoes. In actual experience two or three 
such cones burned during the course of an evening have given much relief from 
mosquitoes in sitting rooms. It does not kill the insects, however, and is at best 
but a palliative. . 
The mosquitoes found on the ceilings of bedrooms in the evening may be quickly 
and easily killed by means of a small, shallow tin cup (such as the lid of a blacking 
box) nailed to the top of a stick and wet inside with kerosene. This cup is placed 
over the quiescent mosquito, which immediately drops or flies against the oily sur- 
face and is killed. But altogether the most satisfactory means of fighting mos- 
quitoes are those which are directed to the destruction of the larv or the abolition 
of breeding places. These measures are not everywhere feasible, but in many places 
there is absolutely no necessity for the endurance of the mosquito plague. The prin- 
cipal remedies of this class are three: The draining of ponds and marshes, the intro- 
duction of fish into fishless pools, and the use of kerosene on the surface of the water. 
The draining of breeding pools needs no discussion. Obviously the drying up of 
such places will prevent mosquitoes from breeding therein, and the conditions of a 
successful application of this measure will, it is equally obvious, vary with each 
case. 
The introduction of fish into fishless ponds is feasible and advisable in many cases 
where the use of kerosene on the surface of the water would be thought undesir- 
able. In tanks supplying drinking water, for example, fish would destroy the mos- 
quito Jarve as fast as hatched. A case is recorded in Insect Life (Vol. IV, p. 223) 
where carp were employed in this way with perfect success by an English gentleman 
living in the Riviera. At San Diego, Tex., the people use for this purpose a little 
fish, called there a perch, the species of which the writer has not been able to ascer- 
tain. Probably the common voracious little stickle-back would answer admirably 
as a mosquito destroyer. 5 
Probably the best, and certainly the easiest, of wholesale remedies against mos- 
quitoes is the application of kerosene to the surface of breeding pools. The sugges- 
tion that kerosene could be used as a remedy for mosquitoes is not new and has been 
made more than once. Exact experiments out of doors and on a large scale were 
made in 1892 by the writer. These and subsequent experiments show that approxi- 
mately 1 ounce of kerosene to each 15 square feet of water surface on small pools will 
effectually destroy all the larve and pup in that pool, with the additional advan- 
tage that the adult females, not deterred from attempting to oviposit, are killed when 
they alight on the kerosene-covered water. Ordinarily, the application need not be 
renewed for amonth, though varying circumstances may require more frequent appli- 
cations in certain cases. 
Since 1892 several demonstrations, on large and small scales, have been made of 
the practicability of this method. Under the writer’s supervision two lucalities 
were rid of mosquitoes by the use of kerosene alone. It will, however, probably 
not prove feasible to treat in this way the large sea marshes along the coast where 
mosquitoes breed in hordes, although even here the remedy may prove to be practi- 
cable under certain conditions and in certain situations. In inland places, however, 
where the mosquito supply is derived from comparatively circumscribed pools, the 
kerosene remedy will prove most useful. In some California towns, we are informed, 
the pit or vault behind water-closets is subject to flushing with water during the 
irrigation of the land near by. A period of several weeks elapses before more water 
is turned in, and in the meantime the water in the pit grows stagnant and becomes 
the breeding place of thousands of mosquitoes. Where, as in certain towns and 
cities, house drainage runs into such a pit and an outdoor privy with a seldom 
closed door is built over it, mosquitoes will breed all summer in the fluid contents of 
the vault, and of course will infest all the adjacent houses. 
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