Photographer's notes: I shared this photo with several experts on the Neotropical Geometridae. All expressed an inability to attach a genus name, and in fact there was some collective uncertainty whether this moth pertains to subfamily Geometrinae or to subfamily Larentiinae. For now we'll just have to label this one "unidentified Geometrid."
Photo data: 31 May 2008. At lights. Tandayapa Valley, Ecuador.
GPS data: 0.003, -78.6785. Elevation 1800 meters above sea level.