Mosquitoes play a vital role in ecosystems.
To humans, mosquitoes represent anything from a nuisance to a threat. Female mosquitoes require blood for their eggs; in drawing it, they leave an itchy welt. Depending on who the mosquito had bitten previously, it may leave the victim with a mosquito-borne illness, such as malaria or West Nile virus. However, these common insects fill important ecological niches.
Food
During their life cycles, mosquitoes live in water and on land. Their larval and pupal stages take place in the water where they form the basis of other insects' diets. Dragonfly nymphs thrive on mosquito larvae. Fish also eat these aquatic organisms. Mosquitoes that live to pupate and emerge from the water in their familiar winged adult forms make up the majority of many predators' meals. Insectivorous bats, small birds, frogs and spiders rely on abundant mosquito populations to survive.
Predators
Predatory mosquito larvae consume other species' young. The Wyeomyia mosquito produces carnivorous larvae, as does the Toxorhynchites. Toxorhynchites larvae are not only carnivorous but cannibalistic, consuming their own species in addition to other larvae. As predators, mosquitoes control other insect populations, eating eggs and larvae before they reach adulthood. Scientists and conservationists are studying the viability of using these predatory mosquito species to control other mosquito populations.
Host Organisms
To the organism that causes malaria in humans, a mosquito is an essential host. Infected mosquitoes spread the malaria-causing Plasmodium parasite to humans via their bites; the infected individual, in turn, infects mosquitoes that bite him. Malaria is directly contagious only in extreme situations such as blood transfusions; otherwise the disease requires a mosquito to spread it. Heartworms that afflict dogs and cats require mosquitoes to carry out their life cycles as well. The organisms responsible for dengue, West Nile virus, various forms of encephalitis and yellow fever also thrive in mosquitoes.
Pollinators
Only female mosquitoes bite; males are incapable of puncturing skin and instead feed on nectar. Like other flower feeders, they are important plant pollinators, especially for certain species of grasses and orchids. Without pollinators to ferry pollen from one plant to another, plant species suffer population declines. Scientists speak of mosquito control, not eradication, because of the role these organisms play in their ecosystems.
Tags: control other, life cycles, mosquito larvae, mosquito populations, Nile virus, their life