Metapolybia aztecoides is a species of vespid wasp. Vespid wasp predation is speculated to be another possible contributing cause. A yellowjacket is a black-and-yellow vespid wasp. Protopolybia exigua is a species of vespid wasp found in South America and Southern Brazil. Vespid wasps build complex nests from paper-like material where they lay eggs in individual cells. An example of this is the fly "Spilomyia longicornis", which mimics vespid wasps.