Elachyophtalma semicostalis is a moth in the family Bombycidae. It was described by Walter Rothschild in 1920. It is found on New Guinea.[1]
The wingspan is 48–58 mm. The forewings are thinly scaled with sooty black brown, the basal half with an olive tinge and the basal three-fifths of the costal area orange buff. The basal two-thirds of the hindwings is sooty black brown, the outer two-fifths orange golden.