Nerthra ranina (Herrich-Schaeffer, 1853)

Mononyx raninus Herrich-Schaeffer, 1853: Wanzenart. Ins., 28.

Nerthra ranina: Todd, 1955: Univ. Kansas Sci. Bull., 368–371.

General distribution. Colombia, Venezuela, Brazil, Peru, Bolivia, Chile, Paraguay, Argentina, Uruguay (Moreira et al. 2011b).

Habitat. Nerthra ranina has been found in streams, rivers, lagoons and the wet margins of stagnant pools connected to streams (Bachmann 1962c; Estévez & Schnack 1979; Schnack & Estévez 1979; Melo & Nieser 2004; Estévez & López Ruf 2006). Specimens were also collected with pitfall traps in grasslands surrounded by a permanent channel in the Delta of the Paraná River in Argentina (Nanni et al. 2011).

At the INR, this species was found moving or resting among the flooded grass, aquatic rooted plants, or on the bottom in the Laguna Iberá (Estévez & López Ruf 2006; Estévez et al. 2010). It was also observed submerged, walking or resting among the aquatic plants or on the bottom, and swimming on the water surface with their fore legs folded and propelled by their second and hind legs (Estévez et al. 2003, 2010; Estévez & López Ruf 2006).