Field notes from Isla Colon:

 

This individual came to a mercury vapor light on the top of a hill on a rainy night in June. Rothschildia are diffiult to tell apart in some cases, and I've found two different-looking males on Isla Colon. I solved the problem by thinking of them as form I and II. The moth pictured here, form I, is a bright cinnamon-brown color; form II, which you can see here, is a darker brown..

 

The females I have found on the island all look about the same, colored somwhere between the male forms I and II.

 

 

Identification source link:

 

http://www.boldsystems.org