Mosquitoes are becoming more abundant in southern Arizona, and so are human cases of mosquito-borne disease. The most significant mosquito-borne disease in the state, the west Nile virus, was virtually unheard of in the southwest 15 years ago, but now, mosquitoes are transmitting this disease to numerous residents of Maricopa and Pima Counties. Unfortunately, mosquitoes infected with the west Nile virus may be growing in number at higher elevations in more northern areas of the state, as infected mosquitoes were collected from Flagstaff less than two weeks ago. The last human cases of west Nile in Flagstaff were reported back in 2010, but another batch of west Nile-infected mosquitoes were collected in Flagstaff three months ago, indicating that the local population is at an increased risk of contracting the infection this year. Culex quinquefasciatus is one mosquito species that can transmit west Nile to humans, and this species thrives within urban and suburban areas where it breeds in stagnant water sources found in residential yards.
Culex quinquefasciatus is more commonly known as the “southern house mosquito,” and this species can be identified by the five lines that adorn its abdomen. However, identifying this species by physical features is both difficult and unnecessary, as southern Arizona residents know this species as the mosquitoes that frequently inflict bites after the sun goes down. This mosquito can also be identified readily by the particularly loud buzzing sound that it produces. This buzzing sound contributes to the species’ reputation as a nuisance pest in and around households, but this species’ is most notable for its ability to transmit diseases from birds to humans. In addition to the west Nile virus, southern house mosquitoes also transmit St. Louis encephalitis and other encephalitis diseases in humans. These mosquitoes even transmit a parasite that causes heartworm in dogs. Southern house mosquitoes are only able to survive due to the ease with which they locate stagnant water sources in human populated areas. Removing containers that have collected rainwater and reducing the amount of water used to feed lawn grass can go a long way at reducing the southern house mosquito population in neighborhoods and parks in the state.
Do you recall sustaining mosquito bites after dark?