Not sure what this is
We took the attached picture in Panama last month. The ball shaped objest (nest?) was covered with the insects. The whole ball was about 5-6 inches across. We saw it nestled in the exposed roots of a tree.
We believe your wasps are in the genus Polybia. That identification is based on images from this fascinating website.
Wow, I am impressed with the speed of your response. I neglected to mention altitude in my original inquiry but we took the picture on the side of Volcan Baru, above the town of Guadaloupe which is at 2130 meters. This fits with the web page description as a “high-elevation species.” Thanks for the answer and for the great web-site.