Mosquitoes are small flying insects that feed on human and/or blood or plant juices. Only female mosquitoes bite to get a blood meal for their growing eggs. Mosquitoes are generally considered nuisance pests, but occasionally can transmit disease. While there are about 43 different species of mosquitoes in South Dakota, most mosquitoes do not transmit West Nile virus. The Culex tarsalis mosquito (the common house mosquito) is the one most commonly associated with West Nile virus.
Where They Live and Breed
Mosquitoes lay their eggs in stagnant water around the home. Weeds, tall grass and shrubbery provide an outdoor home for adult Culex mosquitoes, which also may enter houses through unscreened windows or doors or broken screens.
When Mosquitoes are Most Active
Culex mosquitoes are most active between dusk and dawn when the air is calm, and that is when the females are most likely to bite. However, they may be present at any time of the day.
West Nile Virus and Encephalitis
Viral encephalitis may not have any symptoms at all; mild cases may include a slight fever and/or headache. Severe infections are marked by a rapid onset of a high fever, head and body aches, and usually occur five to fifteen days after exposure. There is no specific treatment for viral infections, other than to treat the symptoms and provide supportive care. Those who may be most susceptible to encephalitis are infants, the elderly and persons with damaged immune systems.