Know Your Mosquito: Culex quinquefasciatus

The common name of the Culex quinquefasciatus is the southern house mosquito, and that really says it all. It is very comfortable in human homes. It is largish and brown, and generally feeds at night, but can be active at other times. Often it rests in a quiet area of your home, then bites you during the night. If you’ve ever been lying in bed and heard the high-pitched whine of a mosquito, it was probably a southern house mosquito. It is most comfortable in warm climates, and is one of the most common mosquitoes in the American South.

Southern house mosquitoes are also known as “quinks” because their scientific name, Culex quinquefasciatus, is difficult to pronounce. In Texas, they are most common in the spring or fall, but are found all summer. They prefer to take their blood meal from birds, but are considered indiscriminate eaters, which means that they will also readily bite humans and other mammals. They take multiple blood meals in their lifetime, meaning they can bite more than once.

Southern house mosquitoes like to lay their eggs in water that is nutrient-rich, which is just a fancy way of saying nasty water full of rotting vegetation; such as leaf-filled gutters, persistent rainwater puddles, culverts, tires, and the like. The females lay eggs in floating rafts of about 100 eggs each, and can lay several rafts in one cycle. The eggs remain in the water for about two weeks, hatch, pupate and then emerge as adults. They can have several generations in one year, and overwinter as pregnant females.

The southern house mosquito’s indiscriminate dining habits also make it more than an annoying nuisance mosquito. Because it feeds on both birds and mammals, and takes multiple blood meals, it can act as a vector for disease. In Texas, it is considered one of the primary vectors for both St. Louis Encephalitis (SLE) and West Nile Virus. For both of these diseases, birds act as a reservoir of the virus. When a mosquito bites an infected bird, and then a human; it acts as a bridge and transmits the virus to the human. Very few viruses can be transmitted this way, and many, including West Nile, can be minor. Most people infected with West Nile are asymptomatic, meaning that they just don’t get sick. Both of these diseases, however, can be serious, and infrequently even fatal. Many counties in Texas, including Williamson and Travis, monitor mosquitoes for WNV.