Syllepte seminigralis is a moth in the Crambidae family. It was described by Warren in 1896. It is found in India (Meghalaya). The wingspan is about 36 mm. The forewings are greyish fuscous, dusted with dark fuscous. The first line is found near the base. It is dark fuscous, angled in the middle, the lower arm vertical. The orbicular stigma is round and the renitorm lunate and obliquely curved. Both are dark-edged, with a centre of the ground-colour. The second line is distinct, blackish, dentate and starts at the costa at about two-thirds. It is vertical for its first third, vertical but slightly nearer the hind margin in the middle and slightly oblique, without denticulations and strongly marked above the inner margin. There is a row of black dashes along the hind margin, separated by pa