The History of the jungle in a Wasp

Polistes actaen wasps congregating inside the shelter of a bromeliad. Serra do Brigadeiro, Minas Gerias, Brasil

Polistes actaeon wasps congregating inside the large protective leaves of a bromeliad, in Serra do Brigadeiro State Park, Minas Gerias, Brasil. Although primarily in the tropical mountain forests of the southern Mata Atlântica, there has been one population identified in the Amazon, on the border of Brasil and Perú. This is because long, long ago, before the arrival of humans, the coastal Atlantic forest used to connect to the Amazon basin.

Perhaps this time overlapped the phase when the Amazon was contracting in some areas due drier, cooler global temperatures. These cooler temperatures allowed this wasp species to migrate to such a distant location, and likely spread out to other areas of the Amazon. However when the temperatures stabilized back to their hotter more humid state, this wasp died out in most of the Amazon. But somehow due to a resistance of local selection pressures or localized abundance of a particular food source they were able to survive.

Although it is not exactly sure they were congregating, these Polistes actaeon wasps at the most of this photo were in a more calm dorminant phase, perhaps in part due drier, cooler temperatures and 40 minutes less daylight. But in Brasil’s summer (the time of North America’s winter), due to the wetter warmer climate and more daylight, they will be more active throughout the forest building new nests.

To see Distrobution of these wasps:

https://www.gbif.org/species/1310608

To learn about the evolution of the Amazon read the John Kricher classic:

https://www.amazon.com/Neotropical-Companion-John-Kricher/dp/0691009740

https://www.jstor.org/stable/j.ctvc77grg