About Rhagastis castor Walker, 1856
Rhagastis castor Walker, 1856 has a wingspan ranging from 53 to 84 mm. It resembles Rhagastis acuta and Rhagastis velata, but is larger, with more elongated forewings and hindwings. It can be distinguished by two combined features: the dark connection between the marginal band and basal area on the underside of its forewing, and its well-developed abdominal golden stripes. On the forewing underside, the marginal area is connected to the basal area via a streak. The third postmedian line is marked by a series of large, conspicuous black vein dots. The median area of both the forewings and hindwings has a noticeable red or salmon pink flush. This species is found in Nepal, north-eastern India, Thailand, southern China, Vietnam, Sumatra, Java, and Taiwan.
