Udea tetragramma is a moth in the Crambidae family. It was described by J. F. G. Clarke in 1965. It is found on the Galapagos Islands. The wingspan is 17-18 mm. The forewings are fuscous, strongly overlaid with ferruginous. There is a straight, transverse, ill-defined, fuscous line at two-fifths of the costa, extending to the dorsum at the basal third. From the apical sixth of the costa extends a transverse, ill-defined line to vein 2, then along vein 2 to the cell, then diagonally, outwardly and then straight to the dorsum at the outer two-thirds. There are three small white dots in the cell, preceded and followed by blackish-fuscous scales. There are also four ochreous-tawny spots on the outer half of the costa, alternating with suffused shades of blackish fuscous. On the termen, there a