The paper reports some observations on the subgenus Aedes (genus Aedes, Diptera, Culicidae) in northeast Italy. Two species were collected: Ae. cinereus and Ae. geminus, the latter recorded for the first time in Italy. Morphological, ecological and biological data of the two species are presented. The identification is possible only on the male hypopigium; larvae, pupae and adult females show no differential characters. For both species, the larval breeding sites were fresh water marshes mainly within woods; preimaginal development took place twice a year, in Spring and Autumn. The females were strongly anthropophilic. No biological differences between the two species were noticed, but more data are needed to ascertain their relationships and the presence of subtle biological divergences.
