Simulium (Pternaspatha) diamantinum n. sp. is described
from females, males, pupae and larvae, collected at Mendoza,
San Juan and Neuquen. Some specimens of this species from
Laguna del Diamante were included before by Wygodzinsky and
Coscaron (1967) in S. strigidorsum Enderlein. The new
species is compared with closely related species of the S.
(Pternaspatha) "nigristrigatum group". The following
synonym is established: Simulium (Pternaspatha)
bachmanni Wygodzinsky & Coscaron = Simulium
(Pternaspatha) nigristrigatum (Enderlein).
