Native species of greater geographical distribution in Argentina.
Disease relations: During the 1982-1983 outbreak in Argentina, strains of Western Equine Encephalitis virus (WEEV) were isolated from pools of Ochlerotatus albifasciatus (Mitchell et al., 1987). The species has been found naturally infected with the Bunyamwera virus in the Santa Fe Province. Experimental studies have shown the species to be susceptible and to really transmit the WEEV to susceptible hosts (Avilés et aI., 1990, 1992). Therefore, the species is the primary mosquito species to be incriminated as WEE virus vector in South America. In 1988 in Chaco Province, Argentina, the species was 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).

Larvae were collected from natural habitats like ephemeral pools formed by rains, overflows of rivers and streams, and flooding of the soil for irrigation. Occasionally it was found in the phytotelm Eryngium cabrerae (Apiaceae). Females are mammalophilic, and they feed readly on horses and cows. The species has been observed to aggressively feed on humans, biting preferably during the day and the night, with a high peak at sunset.