Omiodes monogramma is a moth of the Crambidae family. It is endemic to Kauai, Oahu, Molokai and Hawaii. The larvae feed on Dianella odorata. They feed on the leaves, which they fold together along the midrib and fasten with silk at the margins. Usually there is one caterpillar per leaf. Young larvae begin feeding at the apex of the leaf, and then they gradually work downward, folding together more and more of the leaf as they need it for a hiding place. The surface and substance of the leaf are eaten, leaving the outer epidermis (which is left intact) in a dried up condition enclosing the accumulation of frass. Full-grown larvae are 20–22 mm long and pale yellowish green.