Culex pipiens: The Northern House Mosquito

Why is this Mosquito Important?

  • Culex pipiens is usually the most common pest mosquito in urban and suburban settings

  • Culex pipiens is an indicator of polluted water in the immediate vicinity

  • Culex pipiens is recognized as the primary vector of St. Louis encephalitis (SLE) and West Nile virus in the eastern US.

Where does this Mosquito normally lay its Eggs?

  • In tin cans, buckets, discarded tires and other artificial containers that hold stagnant water

  • In untended bird baths, clogged rain gutters and plastic wading pools that hold stagnant water

  • In storm drains and catch basins in urban areas

  • In septic seepage and other foul water sources above or below ground level

How does this Mosquito Overwinter?

  • The last generation of adult females mate and build fat body by feeding on carbohydrates

  • Mated females find refuge in culverts, basements and protected areas that stay above freezing

  • The body metabolism slows considerably and winter is spent in a state of torpor

  • Females that survive the winter blood feed in spring and lay eggs that produce the summer populations

What is this Mosquito’s Range of Blood Meal Hosts?

  • Culex pipiens is normally considered to be a bird feeder

  • Some urban strains have a predilection for mammalian hosts and feed readily on humans

  • Most populations probably contain individuals that accept blood from mammals as well as birds

What Role does this Mosquito play in the Transmission of St. Louis Encephalitis?

  • SLE is a natural infection found in a variety of wild birds

  • Culex pipiens can function as a vector and pass the virus from one bird to the next

  • If virus is introduced to an urban setting, Culex pipiens can amplify the infection in urban birds

  • House Sparrows, an introduced species, circulate exceptionally high levels of SLE when they become infected

  • Culex pipiens that bite infected birds acquire the virus and are capable of passing it on to humans

 Prepared by:  Wayne J. Crans, Mosquito Research & Control, Rutgers University

This webpage was begun on 7 July 1996 and last updated on 10 May 2010