Perigonia grisea 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 Bolivia

Bolivia

Bolivia officially known as Plurinational State of Bolivia , is a landlocked country in central South America. It is the poorest country in South America...

.

It can be distinguished from all other Perigonia

Perigonia

Perigonia is a genus of moths in the Sphingidae family.-Species:*Perigonia caryae - Cadiou & Rawlins 1998*Perigonia divisa - Grote 1865*Perigonia glaucescens - Walker 1856*Perigonia grisea - Rothschild & Jordan 1903...

species by the uniform grey forewing upperside crossed by narrow, dark brown transverse lines. The hindwing upperside is most similar to Perigonia stulta

Perigonia stulta

Perigonia stulta is a moth of the Sphingidae family. It is known from tropical America.The wingspan is 50-55 mm. Adults are on wing year round....

but the yellow tornal patch is larger.

Adults have been recorded from March to April.