Antispila distyliella sp. nov. (Lepidoptera: Heliozelidae) is described from the Ryukyus, Japan, with biology and morphology of adult and immature stages given. The larva feeds on the leaves of Distylium racemosum Siebold & Zuccarini (Hamamelidaceae), which is a new host plant family for Heliozelidae. The morphology, including chaetotaxy, of the premature (sixth instar) and mature (seventh instar) larvae is described in detail for the first time for Heliozelidae. The final instar, which is a nonfeeding stage in the larval case, has a smaller head, shorter body, and shorter setae than the penultimate instar.