Protopolybia exigua is a species of vespid wasp found in South America and Southern Brazil.
[4] P. exigua continuously seek refuge from phorid fly attacks and thus often flee infested nests to build new ones.
Ducke (1905) morphologically separated Protopolybia from Pseudochartergus and established their close relation due to physical similarity of a medial posterior process on the metanotum.
[2][6] One can determine the wasps' age by evaluating the darkness of the cuticle on the apical edge of the fifth gastral sternite.
This round wing shape may enhance the wasp species' flying abilities and increase fitness.
Immature oocytes that are equal in size to mature eggs can be distinguished due to their cream and less glossy appearance.
[2] P. exigua tend to build their nests in locations facing west; it is suggested that this specific placement leads to higher environmental temperatures and proportionally greater foraging activity.
As time passes, the colony's total egg layers diminish due either to death or from wasp dominance interactions.
According to Noll (1995), the post-swarming stage is when immature wasps are in the mother nest, after the production of sexed individuals and swarming.
The thoracic labial gland is better developed in workers than in queens, but wasp brain size does not differ between castes.
[12] Both inseminated and non-inseminated P. exigua females exhibit a greater presence among colonies that frequently experience nest destruction.
[7] Workers prefer this selective pattern of queen emergence because they are three times more closely related to their sisters than to other brothers on single-queen colonies.
[12] Foraging wasps gather nectar and prey for nourishment and water, resin, and wood pulp for the nest.
Foragers must make recognition flights to get an image of the surrounding landmarks that compose its environment at different distances.
[10] Although the foraging of wasps decreases in rainy weather, the delivery of food and nest material does not stop completely.
Silva (2002) suggests P. exigua participate in a greater amplitude of activity as the latitude of their nesting region decreases.
[10] In Ribeiro Jr.'s study on P. exigua from Brazil, he proposed that the wasp develops its foraging activities more efficiently within a flight range of 75m from its nest.
[3] P. exigua were observed to transfer complete batches of nest material more often after the appearance of a new generation of workers.
[10] Worker polyethism occurs in P. exigua colonies and separates labor based on age of individual wasps.
[12] After the emergence of workers in large colonies, some foragers become specialized in delivering specific types of material to the nest.
[3] The importance of pulp decreases as time passes and as the colony ages; correspondingly, prey collection becomes a priority for foraging workers.
[3] When P. exigua catch prey, they return to the nest with a solid, usually glossy mass, held in their mouthparts.
Wasps were reported to share this food with other adults and offer the protein in a macerated form to larvae.
Wasps return to the nest with a solid mass taken in the mouthparts; they are usually smaller and darker than the prey crop.
Workers carrying resin to the nest travel to substrate sheets and proceed to lay their foraged material on top of the structure.
Foraging wasps crush their caught prey and carry the softened corpses back to the nest.
Megaselia picta females emerge from P. exigua nests and proceed to lay their eggs outside, on the uppermost envelope.
Many of the wasps' traits, such as polygyny and protective nest structures, are suggested to be survival tactics against ant predation pressures.
However, wasps are often unable to eradicate the phorid pupae due to their strong attachment to the cell bottom.
Since P. exigua seem to be specialized against the common predation of ants, Megaselia easily defeat the wasps' defense strategies and frequently invade the species nests.