The immature stages of Wyeomyia argentina were collected in internodes of G. chacoensis, mostly in shaded areas, together with immature stages of Wy. codiocampa, Sabethes undosus and Toxorhynchites theobaldi. Collection environment is characterized by grasslands, palm groves and cattle grazing, influenced by a branch of a river, with G. chacoensis groves, lemon trees, palm trees and some specimens of exotic ornamental plants such as Alpinia, Dracaena fragrans (Stein et al., 2026).