Theretra cajus
Abdomen upperside with two strong white longitudinal lines, which are fused at the anterior and posterior margins of each segment, giving the appearance of a chain (as is sometimes the case in Theretra oldenlandiae oldenlandiae but not in Theretra perkeo). Forewing upperside with dark brown band between first and third postmedial lines and fifth postmedial line contrasting very strongly with the almost white intervening band (in which the fourth postmedial line is faintly indicated); a dark line running along Cu from the wing base as far as origin of CuA1. A distinct discal line present, with another line proximal to it but generally lost in the brown discal area. Submarginal line distinct in most specimens, the marginal band shaded with grey.
Male genitalia: Uncus shorter and broader than in Theretra monteironis, less convex dorsally, apex rounded. Gnathos broad, sides somewhat obliquely rounded, apex narrowed to an obtuse point. Harpe slender, horizontal, curved gradually dorsad distally. Armature of phallus band-like; left lobe shorter than in Theretra oldenlandiae oldenlandiae, with heavy teeth on the proximal edge and few teeth on the distal edge.
Female genitalia: Anterior and lateral edges of ostium bursae raised, smooth, semi-lunar.