Polybia Wasps

 

You may have noticed elongated papery globes hanging from tree branches or palm leaves in the rainforest. Usually a pale tan or gray, these are nests built by tiny Polybia wasps over the course of several months, and contain tiers of honey-combed paper cells in which eggs are positioned and the pupae fed and cared for until they hatch into yet more wasps. 

A colony of these little wasps created a nest on the underside of my veranda ceiling. It is an elongated cylinder about 7” x 11”, and was fascinating to watch take shape as the wasps gathered on the chosen spot, went out to collect and chew up dried grasses or leaves, and other workers glued them, using water collected by forager wasps, into shape over the course of many weeks.  There’s an interesting article about that here. 

These little wasps, barely half an inch long, are peaceable, although they can, and DO, sting if antagonized. I photographed and sketched “my” nest daily, perched on a ladder within inches of their activity. They would gather briefly into defensive clumps when I first appeared, then they would gradually lose interest and forget all about me – they had important stuff to do: feeding babies, going out to forage, building more nest tiers, covering the tiers with the outer casing, etc. 

The nest is empty now. I don’t know why they left, maybe they outgrew it? Did my gutter repair three feet away make too much noise? But even after several years, the empty nest is still nearly intact and interesting to examine. The nest in the picture here was one I found hanging on the underside of a spiny palm tree. That was probably excellent protection, since I suspect a nest raider (coati, opossum, kinkajou, etc.) would not come creeping up that palm tree for lunch if it could find anything else to eat!

Many species of Polybia wasps range throughout Central and South America. I’ve found two different species within walking distance of my house (the other had orange wings and different markings), but they all have pretty much the same habits. Consider it a privilege if a Polybia colony takes up residence at your place. They don’t make a mess, are peaceable neighbors if you don’t mess with them, are fun to watch, and they’re a tribute to your willingness to be an environmentally friendly part of their rain forest. They, and their attractive nest, make a great conversation piece, as well.

Some interesting info here.