Length: hopper in photo 4 mm
Determined by Dr. Lois O'Brien, Green Valley, Arizona, who comments that insects in tribe Cenchreini have a row of pustules on each lateral side of the vertex. Among the likely genera are Persis, Herpsis, or Neocenchrea. Generic ID would be facilitated by having a specimen in hand.
Photo notes: Colakreek, Para district, Suriname. The hopper was attracted to lights in an area where savanna met tropical forest.
American Insects site