Pseudopostega triangularis is a moth of the family Opostegidae. It was described by Donald R. Davis and Jonas R. Stonis, 2007. It known only from the type locality, in the north-central forests of Argentina.
The length of the forewings is about 2.6 mm. Adults are on wing in November.
External links A Revision of the New World Plant-Mining Moths of the Family Opostegidae (Lepidoptera: Nepticuloidea)