Tridrepana sera is a moth in the Drepanidae family. It was described by Watson in 1957. It is found on Fergusson Island and in New Guinea. The wingspan is about 27-31.6 mm for males and 33.6-36.8 mm for females. The forewings are dull yellow with obscure markings. There is a rufous spot on the upper vertical arm of the discocellular, and a white rufous-edged spot at the lower angle of the cell, as well as a rufous curved line near the base, plainest on the inner margin. There is also a rufous outer line from the centre of costa to middle of the inner margin, strongly outcurved and thickened opposite the cell, then oblique inwards. The submarginal line is curved and consists of blackish spots between the veins, that are most distinct and swollen opposite the cell. The apical region is suffu