Nyceryx riscus is a moth of the family Sphingidae.
It is found from Belize and Mexico to Costa Rica and further south to Bolivia and Argentina.[1]
The wingspan is 50–58 mm. It is similar to Nyceryx stuarti but smaller and paler. There is an indistinct, grey-centred discal spot and a conspicuous black dot distal of it towards the costa on the forewing upperside.
Adults are probably on wing year round.
The larvae feed on mature leaves of Xylophragma seemannianum. They have a solid green tail horn with well-developed bumps. The body is a yellowish or pale green with pale yellow lateral diagonal slashes. The head is pale green with a trace of blue wash.