There are many enemies of mosquito larvae, such as tadpoles, water-beetle larvae and various small fish such as “millions.”
Terni suggests the using of such fish as carp and tench which have a food value as well as a larvicidal one.
(b) Measures against the mosquito. The clearing away of grass and brush from around houses exposes the mosquitoes to the sun in which they cannot live long.
When inside the house they may be destroyed by sulphur fumigation, 1 or 2 pounds of sulphur for each 1000 cubic feet and with an exposure of two hours.
It is usually stated that mosquitoes may hibernate during winter following infection in the autumn and that cases of malaria in early Spring may be explained by their bites. Examination of hibernating mosquitoes for zygotes does not give strong proof to this view but such mosquitoes, becoming active with a rise in temperature, may bite gamete carriers in the house and thus spread malaria.
Pyrethrum powder, which is set on fire with a little alcohol, may be burned, using 2 pounds per 1000 cubic feet, and an exposure of four hours. This does not certainly kill the insect and the stupified mosquitoes should be swept up and burned.
Giemsa’s spray is now considered an excellent measure for killing mosquitoes in rooms. The composition is as follows: Pyrethrum tincture (20 parts powdered pyrethrum blossoms to 100 parts alcohol), 480 grams; odorless potash soap, 180 grams; glycerine, 240 grams. Before using it dilute with 20 times its own weight of water, and spray the walls of the room with a spray pump.
The use of a small square of wire gauze on a handle (fly swatter) to kill mosquitoes as they rest on a wall is of great value in keeping them down in a screened house.
2. Protection of the Individual.