Image of Arctornis naphtha Holloway ♂ (holotype) — ♂ (holotype)

Arctornis naphtha Holloway sp. n.

♂♂ 16-17mm, ♀♀ 19-20mm. This and the next five species are characterised by a number of features that set them apart as a group. The rather broad, somewhat rounded forewings have irregularly reflective transverse bands that give the impression that they have been mottled with crystalline flakes of naphthalene. The discal dot, if present, is faint. The male genitalia have a cupola-shaped uncus, and valves that are narrow, often tapering, with the harpe short, broad, often with robust setae, and not conspicuously based in a saccular pocket. In naphtha the frons and palps are extensively rufous and the legs unspotted as in rufimarginata which differs in having dense, fine wing scales with no mottled satiny reflection. The male genitalia of naphtha have the valve apex irregularly rounded with a corona of setae. The harpe is a small lobe with three to four very robust setae.