Ae. geminus is supposed to be mainly distributed in Central
and Western Europe (Peus, 1972). The distribution stays poorly known
because a large number of records of Ae. cinereus actually
must correspond to this species (Schaffner et al. 2001, Becker et
According to Schaffner et al. (2001) it is a typical flood-plain
species; breeding sites were located in areas liable to be flooded
with fresh waters, like prairies and flooded forests; ground and
arborescent vegetation is often abundant. In Austria larvae were
found in May in shallow temporary stagnant waters in peat bogs,
near the border to Czechia, associated with Cs. morsitans,
O. communis, O. diantaeus and O. punctor.
The species is polycyclic, showing at least two generations (Schaffner
et al. 2001, Becker et al. 2003). After hibernation in the egg-stage,
first larvae hatch in spring after snowmelt; hatchings follow one
another until the end of summer; adults are found up to the first
frosts (Schaffner et al. 2001).
Females are aggressive toward humans; they can fly far from their
breeding sites and may cause a strong nuisance (Schaffner et al.
2001, Becker et al. 2003). The medical importance is unknown (Schaffner
et al. 2001).