The following points highlight the top five methods used for controlling mosquitoes. The methods are: 1. Personal Protection 2. Destruction of Adults 3. Destruction of Larvae 4. Elimination of Breeding Places 5. Preventive Medicine.
Method # 1. Personal Protection:
(a) In mosquito-infected area protective clothing may be used, such as will cover the exposed parts of the body, especially after sunset,
(b) Mosquito repellents are also useful, like mosquito cream, citronella, odomos and Indalone which keep mosquitoes away. Repellent No. 448 of the American navy is very effective for long periods,
(c) While sleeping fine mesh mosquito nets prevent them from biting and bed rooms or houses could be screened to prevent entry of mosquitoes,
(d) Painting walls with creosote repels mosquitoes.
Method # 2. Destruction of Adults:
(a) Killing of mosquitoes can be done be spraying liquid insecticides like flit or D.D.T., the latter not only kills mosquitoes but also makes them leave a house,
(b) Fumigation of dwellings with sulphur dioxide is also useful,
(c) A mixture of water and 10% D.D.T. in oil sprayed from the air is very effective in killing large number of mosquitoes in towns, ponds, marshes and forests.
Method # 3. Destruction of Larvae:
It is easier and more effective to kill mosquitoes in their larval forms than as adults, and several methods are used with success,
(a) Oiling:
The breeding places of mosquitoes are sprayed with petroleum oils, the oil film formed on the surface of water does not asphyxiate the larvae, as is commonly believed, but is toxic to them, the oiling must be repeated to kill those larvae and pupae which will hatch later.
(b) Panama Larvicide:
Panama larvicide is a mixture of caustic soda, resin, and phenol in water, it has been used most effectively in the Panama Canal region. The Panama larvicide mixes well with water and kills both the larvae and the algae on which they feed. One part of Panama larvicide is sufficient for 10,000 parts of water.
(c) Paris Green:
Paris green is a powder of arsenic mixed with fine dust, one part of powder with 100 parts of dust. This can be thrown in the wind and it will cover the surface of a pond; it is insoluble in water and remains floating and is eaten by surface feeding larvae of Anopheles’, it will kill the larvae but not pupae. It is effective only against those larvae which feed on surface.
(d) Natural Enemies:
Fishes, minnows and Gambusia live on larvae and pupae of mosquitoes, and their introduction in a breeding place is helpful, but for this the brush and floating vegetation must be cleared so that the fish can reach the larvae.
(e) Chemical Larvicide:
One part of D.D.T. emulsion in thirty million parts of water is used most extensively as a spray to kill larvae, but it takes 50 hours. Planes can be used for this purpose on large areas.
Method # 4. Elimination of Breeding Places:
For those mosquitoes which breed in rain-filled containers and cisterns, like Aedes, emptying of water is effective. For large ponds and swamps digging a sloping ditch removes large volumes of water. Small ponds can be filled up with mud. In India cycles of 5 wet days followed by 2 to 4 dry days were found to be highly effective in controlling Anopheles in fields.
Method # 5. Preventive Medicine:
Daily doses of quinine are effective against mosquito bites, but a successful vaccine has yet to be found for yellow fever.