Mosquitoes are small insects living in houses or near the houses. They are found all over the world. The body of the mosquito consists of three segments i.e. head, thorax and abdomen. The head is conical in shape and bears a long needle like structure called the proboscis with which the mosquito bites.
The thorax has a pair of wings and three pairs of legs. When the mosquito is at rest the wings are folded. The buzzing noise of the mosquito is produced by the beating of their wings. The female mosquito bites and sucks the blood of human beings and pet animals.
The male mosquito does not bite and lives on plant juices. Blood meal is necessary for producing eggs. With each bite by the mosquito blood is sucked and a small fluid is injected in the blood which leads to itching sensation and discomfort to the person.
The female mosquito after sucking blood, lays eggs on the surface of water in wells, cisterns, fountains, water receptacles etc. In rural areas it breeds in pools, banks of streams or canals, drains or garden pits containing seepage water.
They also breed in gully traps, masonary tanks and on collection of dirty water around houses and stables. During the course of season the female mosquito may lay eggs several times and 100 to 200 even more at a time. Like other insects mosquitoes also have four stages in their life cycle i.e. egg, larva, pupa and adult.
There are three main types of mosquitoes which spread the diseases. They include:
Female anopheles spread malaria. Anopheles mosquitoes breed in clean water.
The culex mosquitoes are more prevalent than anopheles mosquitoes. Female culex spreads filaria and viral encephalitis. Culex mosquitoes breed in dirty and polluted water. The favourite breeding places are gully traps, open drains, masonary tanks, earthen waste vessels and on collection of dirty water around houses and stables.
(iii) Aedes Mosquito:
Aedes mosquito is also known as tiger mosquito. It is generally found in houses and is characteristically marked with white stripes on a black body. Because of these stripes on their bodies they are called ‘tiger mosquitoes’.
The females are blood suckers and bite during day and night. These mosquitoes are most abundant during rainy season. They breed in artificial collections of water i.e. water found in broken bottles, flower pots, fire buckets etc. Aedes mosquitoes are responsible for spreading yellow fever (not present in India), dengue fever and hemorrhagic fever.
The male mosquitoes do not bite, only the female mosquitoes bite because they need blood for laying eggs. Some mosquitoes live on human blood whereas others live on animal blood.
The mosquitoes which live on human blood are more dangerous than those who live on animal blood. The life of male mosquito is not more than 1-3 weeks whereas female mosquitoes may live up to 4 months or more.
Mosquitoes prefer to live at dark places. Some mosquitoes like anopheles avoid heat and light therefore during day time they remain hidden in the corners, under luggage or in the shoes and come out from their hiding places at night time in search of food. In fact, they become more active after sunset and just before sunrise.
After sucking blood, they usually rest on the surface of walls. During winter and hottest months the mosquitoes undergo hibernation in covered places like coolers etc. and do not breed. The mosquitoes cannot fly over long distances but may fly up to 2-3 kilometers from their breeding places.
Control of Mosquitoes:
(i) Do not allow water to stagnate near the houses. Low lying areas must be filled with dust and levelled so as to eliminate the breeding places.
(ii) Sprinkle oil on the surface of water. Oil will spread easily on water and it will kill mosquito larvae and pupae partly by suffocation, drowning action and partly by its toxic action. The oils commonly used for this purpose are crude oil, kerosene oil, petrol and malariol. Sprinkling of oil on water has the drawbacks that it renders the water unfit for consumption and it may also kill the fishes.
(iii) A recent technique is that some kind of fish like Gambusia, Barbados, lebister are grown in water. The fish readily feed on mosquito larvae thus causes reduction is mosquito larvae.
(iv) Houses and cattle sheds should be sprayed with insecticides, a wide variety of which are available in the market. These insecticides include DDT, BHC, and Malathion etc. which are recommended for control of adult mosquitoes. These insecticides may be sprayed on the walls and roofs with an ordinary stirrup pump or still better with a compression pressure sprayer.
(v) Mosquito repellants should be used in the houses or applied on the body.
(vi) Mosquito nets should be used.
(vii) Doors, windows and ventilators of buildings should be fitted with fine gauge so that mosquitoes and other insects may not enter inside the building.
(viii) Regular cleaning of houses and unused articles should be done so as to prevent hiding of mosquitoes.