Disease relations: During studies carried out in 1988 in Chaco Province of Argentina, Culex acharistus was the most abundant (and for this reason suspicious of being the vector) species when cases of Eastern Equine Encephalitis were occurring in horses (Avilés et al. 1989).The species has been found naturally infected with the Bunyamwera virus in Formosa Province (Gallardo et al., 2019).

Larvae of Culex acharistus were collected mainly in natural sites, in different climates and seasons: marshy expansions of stream plains; permanent natural pools originated by rainfalls or overflowing, between rocks; and shaded, vegetation-free, rocky temporary pools (Laurito et al., 2009; Linares et al., 2016). Immature stages were also reported in artificial breeding sites such as disused tires, swimming pools, and plastic and metal containers (Rossi & Almirón 2004). Larvae were collected together with Culex apicinus specimens in natural, permanent, and semi-permanent bodies of water including ditches and pools created by overflowing rivers and the rising water table (Díaz Nieto et al., 2020). Females were captured with cylindrical lard-can traps with rabbit, chicken, toad, and turtle bait, as well as on humans (Almirón & Brewer, 1995).