Darapsa bhaga Moore, , Proc. zool. Soc. Lond. 1865: 794. Type locality: [India,] Northeast Bengal.
Synonym. Darapsa bhaga Moore, .
Wingspan: 82--84mm. Superficially similar to species of Daphnis, particularly Daphnis hypothous hypothous and Daphnis layardii, but easily distinguished by the falcate apex of the forewing, which also lacks a large oval dark green basal patch on the upperside. Similar to Eurypteryx obtruncata but forewing outer margin less curved and hindwing apex evenly rounded. Easily distinguished from other species of Eurypteryx, except Eurypteryx obtruncata, by the incomplete line on forewing upperside from costa towards middle of outer margin dividing light brown apical area from deep brown discal area; antemedian band with a pale basal edge. Hindwing upperside almost uniformly dark brown with a lighter patch at tornus. Forewing underside with two distinct median lines.
In northern Thailand, July at 1400m altitude.
Larval hostplants. Alstonia (Apocynaceae). Robinson et al. (2001) give Alstonia scholaris, as do Eitschberger & Ihle (2014) for Thailand.
China: Shaanxi (Taibai Shan); Yunnan.
Nepal, Bhutan (Irungbam & Irungbam, 2019), northeastern India, southwestern to central China, Thailand, Malaysia (Peninsular, Sarawak), Indonesia (Sumatra, Java, Kalimantan).