The larva of Argia cuprea (Hagen, 1861) is described and figured. It falls into the group of Argia larvae with prominent ligula and one palpal seta, but it differs from its closest relatives by a combination of features such as male gonapophyses reaching posterior ventral margin of S10; dorsal and ventral margin of paraproct with long, abundant, white, delicate setae on distal 0.40; tip of paraproct 20% its total length; lateral surface of paraproct with abundant spiniform setae restricted to the triangular, yellowish-brown, slightly sclerotized area along the inflated area. It appears closely related to A. oenea Hagen in Selys, 1865 and A. orichalcea Hagen in Selys, 1865 larvae.