Type locality: Canal 6 and Paraná de las Palmas, Estación Agropecuaria Delta, Buenos Aires, Argentina. 45F, 37M, 126L, 82 lpAd, García & Casal.
Disease relations: Specimens identified as Culex brethesi / eduardoi were recorded naturally infected with Saint Louis Encephalitis virus in rural and urban environments during autumn and spring in Chaco Province (Oria et al., 2025).
Larvae have been collected in puddles, associated with Culex dolosus and Culex maxi. In artificial containers, the species has been collected from disuses tires with other mosquito species such as Culex pipiens and Toxorhynchites theobaldi.