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)
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