Mosquito larvae live in water until they pupate and develop into adult mosquitoes. Mosquito larvae are protected in an oily sack called a cocoon, which is difficult to break down. Mosquitoes prefer stagnant water within which to lay their eggs. They most commonly infest ponds, marshes, swamps and other wetland habitats. However, they are capable of thriving in a variety of locations and can successfully grow in numbers even when not in their natural habitat.

Many species of mosquitoes use containers of water as egg-deposit sites. Hot, humid environments are most amenable to mosquito growth and survival. Infestations can occur easily in tropical areas. Some species have also been known to inhabit freezing locations such as the Arctic Circle. Mosquito larvae can be found in various habitats.

Some larvae are active in transient waters such as floodwater, ditches and woodland pools. The Anopheles, Culex, Culiseta, Coquillettidia and Uranotaenia species breed in permanent bodies of water and can survive in polluted water as well as freshwater, acid water and brackish water swamps. Other mosquito larvae may be present in container water sources such as puddles, upon leaves and in stagnant water within small pools.

The larvae of most species use siphon tubes for respiration; however, some larvae cling to plants to access air supplies. Mosquito larvae consume microorganisms and organic matter in water. Mosquito larvae may be as large as about 5mm and can be clearly visible in water. Larger larvae are located closer to the water’s surface.

Mosquito larvae are extremely sensitive and will submerge for protection if they sense disturbance. Mosquito control involves the elimination of existing infestations and the prevention of re–infestation through the eradication of larval populations. In order to control mosquito larvae, regular inspections of possible breeding sites should be conducted.

Because mosquito larvae cannot survive away from water, areas affected should be combed for water sources. Water that has been stagnant for three days is a prime habitat for mosquitoes. Some species require minimal amounts of water to thrive; even water sources such as birdbaths are potential breeding sites.

About 3.3 billion people – approximately half of the world’s population – are at risk of malaria. In 2010, there were about 219 million malaria cases (with an uncertainty range of 154 million to 289 million) and an estimated 660000 malaria deaths (with an uncertainty range of 490000 to 836000).

Every minute, a child dies from malaria. Malaria causes significant economic losses in high-burden countries. In high-burden settings, malaria can trap families and communities in a downward spiral of poverty, disproportionately affecting marginalised and poor people who cannot afford treatment.