This work reports observations on adult Culicidae activities for diurnal and crepuscular-nocturnal forest species occurring in the area of Casa Grande, located at the Northeast region of the State of São Paulo, Brazil. These investigations, were carried out during the 1963 to 1966 period. They recorded the specific composition, distribution, year cycle of abundance, vertical stratification in the forest, and the possible relationship of these forest mosquitoes to the housekold environment. Since these region is considered a biome of the Anopheles (Kerteszia) cruzii particular attention was dedicated to this species, considered as an important malaria vector. Beside this, several Sabethini species proved to be considerably abundant and, along with some culicines as Aedes serratus, showed activities that may put these mosquitoes in relation with humans and domestic animals. Regarding the domesticity of these mosquitoes, Anopheles cruzii proved to be a considerable house visitor and this suggest that it may be incriminated for the transmission of forest virus and other infectious agents to humans and domestic animals. This mosquito proved to be of the acrodendrophilic species and some preference of it by avian blood is suggested.
