A mantid, bright green, about 4" long, which resembles Mantis religiosa, but Wickipedia seems to say they aren't in South America where this was spotted. I believe that is an egg case glued to a buttress of the Ceiba tree.
This mantis was hanging out between the buttresses of a giant Ceiba tree, along the south bank of the Amazon River, in rainforest.
I would appreciate it if someone could confirm that Mantis religiosa are found along the upper Amazon in Peru.... LATER: One of our members has confirmed that Mantis religiosa does NOT live along the upper Amazon, and that this mantid's characteristics are consistent with Oxyopsis peruviana. I'm happy with that. So be it!