Protambulyx eurycles is a species of moth of the family Sphingidae first described by Gottlieb August Wilhelm Herrich-Schäffer in 1854.
It is known from Suriname, Guyana, French Guiana, Colombia, Ecuador, Peru, Bolivia, Brazil, Costa Rica, Nicaragua and Mexico.[1]
It is similar to Protambulyx euryalus but the forewing marginal band is much broader and the proximal edge is crenulated. Females are less heavily marked than males.