These little bees are sitting on the tubular entrance to their hive. I first noticed the colony several years ago, and it is one of several in the immediate area. The entrance looks exactly like a dead vine. It was only the movement of the bees that alerted me to it. The bees are about 4mm long, and the hive is located in a tree buttress at La Selva Bio Station.
I suspect wasps. I don't think there is much left of the poor caterpillar, and more wasps will emerge from it.
Another beautiful little construction. This one is neatly plugged. This means the mum wasp has laid her eggs, provisioned the nest with a paralyzed caterpillar or two, and moved on. When the wee baby wasp has dined and pupated, it will emerge and come forth to start the process anew.
