Hippotion echeclus
Most similar to Hippotion boerhaviae, Hippotion rafflesii rafflesii and Hippotion rosetta but immediately distinguishable by the black base to the hindwing upperside. In this respect, Hippotion echeclus resembles a small Hippotion gracilis from which it can be distinguished on male genital structure. Upperside of thorax with a pale grey medial stripe. Forewing upperside similar to Hippotion boerhaviae and Hippotion gracilis but the oblique postmedial band very pale, appearing to divide the wing into three sections. Hindwing orange-pink with a black basal patch and a brown marginal band; tornal area buff.
Male genitalia: Uncus much stouter than in Hippotion eson, sinuate. Gnathos triangular, tapering to a point, apex upcurved, almost hooked. Harpe globose with an apiculate thorn-like process and one or more teeth on the ventral edge; dorsal edge with long scales. Phallus with a curved row of teeth on the left and a few subapical teeth on the right; no process.
Female genitalia: Ostium bursae as in Hippotion eson but the ridge around the ostium not as distinct and gradually reducing.