torrentium is a Palaearctic species, distributed in Northern
and Central Europe, Asia Minor, Iran and extending eastwards as
far as western Siberia (Cranston et al. 1987, Schaffner et al. 2001).
stages may be encountered in a variety of breeding sites, including
rock holes, pools along torrents, water puddles and watersides of
ponds, or artificial habitats like tires, barrels and containers
(Mohrig 1969, Briegel 1973, Cranston et al. 1987, Schaffner et al.
2001, Becker et al. 2003). The water can be fresh or brackish, very
dirty or rich in iron oxide; the sites are generally small, open
or under a forest canopy, lacking underwater vegetation; larvae
are often associated with those of C. pipiens (Schaffner
et al. 2001). Contrary to C. pipiens, C. torrentium
is adapted to lower water temperatures and dominates in cold regions
or at higher altitudes (Mohrig 1969, Schaffner et al. 2001). Moreover
C. torrentium is the only Culex species recorded
from natural tree holes (Onyeka 1980).
species is multivoltine; eggs are laid on the water surface and
larvae are present during the summer, from spring to the beginning
of autumn (Schaffner et al. 2001). According to Becker et al. (2003)
the larval development seems to be slower than in C. pipiens,
which may result in only one generation per year in northern countries.
Adults are present during the summer until the first frosts. C.
torrentium overwinters as fertilized, diapausing females in
shelters, such as hollow tree trunks, caves or cellars (Cranston
et al. 1987, Schaffner et al. 2001).
have been observed feeding on flower nectar, mostly at night; females
are considered as ornithophilic; they are vectors of the Sinbis
virus (Ockelbo) (Service 1968b, Schaffner et al. 2001). The species
has never been recorded to bite man (Becker et al. 2003).