Adhemarius gannascus is a moth of the family Sphingidae first described by Caspar Stoll in 1790.

Distribution: It is known from Jamaica, Mexico, Belize, Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, Panama, Colombia, Ecuador, Peru, Venezuela, Panama, Guyana, Suriname, French Guiana, Bolivia, Brazil, northern Argentina, southern Paraguay and Uruguay.

 The wingspan is 92–112 mm for males and 98–124 mm for females. Adults are on wing year round.

Biology: The larvae have been recorded feeding on Ocotea veraguensis, Persea povedae, Persea americana and Damburneya salicina.

Taxonomy: 

• Adhemarius gannascus cubanus (Rothschild & Jordan, 1908)
• Adhemarius gannascus jamaicensis (Rothschild & Jordan, 1915)