Culex pipiens: The Northern House Mosquito

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)

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

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

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

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