According to the UC Division of Agriculture and Natural Resources, prevention is the best method of eradicating mosquito larvae and can be supplemented with chemical and biological means when necessary. Elimination of breeding sites is key when ridding mosquito larvae. Bodies of water more than 24 inches deep are difficult for mosquito larvae to live in, so vigilance is necessary when dealing with water-containing structures containing less than this amount.
Bodies of water with steep slopes also discourage mosquito larvae. While they can live in great numbers, they are also concentrated in small spaces. The removal of excess debris and vegetation ensures that the mosquito larvae have limited food, less shelter and more availability to natural predators. Biological means of control include fish, dragonflies and backswimmers.
The use of pesticides is not encouraged, as it can negatively affect other species which prey on the mosquitoes and their larvae. Larvicides featuring the bacterium Bacillus thuringiensis israelensis, however, are an acceptable avenue when dealing with especially difficult circumstances.
Mosquito larvae swim by using propulsion through their mouth brushes or through wiggling their bodies. The presence of small, wiggling organisms within a water sample can indicate their presence. Mosquito larvae do not bite and have limited mobility. Before becoming adults, mosquito larvae pass through a pupa stage.