Erechthias grayi is a moth of the family Tineidae. It is endemic to Ascension Island. The length of the forewings is 1.4–1.8 mm. This wing reduction occurs in both sexes. It is one of the few species of Lepidoptera known where this extreme of brachyptery involving both sexes has evolved. The forewings are dark fuscous with an irregular scattering of dull white scales at the base of the wing and mostly crossing the wing beyond the middle. There is a slightly larger concentration of dull white scales at the apex and extending a short distance along the costa. The hindwings are minute, slightly variable in size and without scales.