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Distribution:
The
species is widespread throughout Europe, the Middle East and up
to Siberia (Cranston et al. 1987, Schaffner et al. 2001, Becker
et al. 2003).
Habitat:
Aquatic
stages of Coquillettidia richiardii mostly develop in permanent
stagnant water bodies; the breeding sites include the littoral of
lakes and ponds, swamps, peat or oxbows, overgrown with submerse
macrophytes or helophytes, such as Acorus, Carex,
Glyceria, Nymphaea, Phragmites, Ranunculus,
Sparganium and Typha (Shute 1933, Mohrig 1969,
Guille 1976, Aspöck et al. 1970). Larvae and pupae live attached
to the vegetation in a depth between 30 cm (Mohrig 1969) and more
than one metre (Shute 1933). The water body must not dry up or freeze
up during the larval phase (Mohrig 1969).
Biology:
Eggs
are laid in rafts on a free water surface and hatch at intervals
up to about two weeks after oviposition; both larvae and pupae live
permanently below the water surface and obtain oxygen by piercing
the roots of submerged plants with their modified larval siphons
or pupal trumpets (Guille 1976). The special lifestyle of the larvae
reduces the risk of predation but handicaps nutrition; therefore
larvae breed only in water rich in organic matter and suspended
micro-organisms (Schaffner et al. 2001). Larvae may change their
support, but pupal stages always remain on the same place, fixed
by their respiratory trumpets; they leave their support only a few
hours before imago emergence after breaking the pierced tips of
the respiratory trumpets (Mohrig 1969, Schaffner et al. 2001).
Coquillettidia
richiardii is univoltine (Service 1969a), but may show 2-3
generations in southern regions (Schaffner et al. 2001). First instar
larvae are present from June to September, other instars may be
found throughout the year; larvae develop slowly, though feeding
throughout the winter and almost a year passes between oviposition
and adult emergence (Shute 1933, Cranston et al. 1987). Hibernation
exclusively takes place in the larval stage (Mohrig 1969). Pupae
are found for a short period between May and July (Marshall 1938).
Adults:
In
Central Europe, imagoes hatch at the end of June and are present
throughout the summer till September or October (Marshall 1938,
Trpiš 1962, Mohrig 1969, Rettich et al. 1978, Aspöck et
al. 1970).
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