Xylophanes monzoni is a moth

Moth

A moth is an insect closely related to the butterfly, both being of the order Lepidoptera. Moths form the majority of this order; there are thought to be 150,000 to 250,000 different species of moth , with thousands of species yet to be described...

 of the Sphingidae

Sphingidae

Sphingidae is a family of moths , commonly known as hawk moths, sphinx moths and hornworms, that includes about 1,200 species . It is best represented in the tropics but there are species in every region . They are moderate to large in size and are distinguished among moths for their rapid,...

 family. It is known from Guatemala

Guatemala

Guatemala is a country in Central America bordered by Mexico to the north and west, the Pacific Ocean to the southwest, Belize to the northeast, the Caribbean to the east, and Honduras and El Salvador to the southeast...

.

The length of the forewings is about 41 mm. It is similar to Xylophanes falco

Xylophanes falco

Xylophanes falco is a moth of the Sphingidae family. It is found from Honduras and Guatemala north through Mexico to southern Arizona and western Texas. It is generally found in oak woodland and along streamsides....

, but generally darker, with a more diffuse pattern and less falcate forewings. Furthermore, the underside of the abdomen is lacking the two longitudinal grey lines. The forewing upperside is similar but the pale brown-beige area basad of the postmedian lines is covered with scattered black scales. The distal median line is almost reaching the discal spot, the basalmost postmedian line is straight and the postmedian and submarginal lines are less conspicuous against the ground colour. The submarginal and marginal bands are both very dark grey, almost black.