Mischocyttarus drewseni, which is sometimes spelled "drewsenii", is a social wasp in the family Vespidae.

[1] It is commonly found in Neotropical regions of South America, including Brazil, Peru, Venezuela, Colombia and Paraguay.

This mid-sized wasp is about 1.5-1.8 cm and is typically dark brown or black in color.

This species makes their nests out of woody plant fibers and create single combed nests with hexagonal cells which are typically found in low lying grass habitats or semi-urban environments.

It feeds on arthropods, plant nectar, and honeydew, and the species is very protective of its brood when it comes to defending them from their predators.

[1] Within the Vespidae, M. drewseni belongs to the subfamily Polistinae which is typically found in tropical regions and comprises 25 genera.

There are also distinctive features in Mischocyttarus larvae, including one to three lobes on their first abdominal segment and large thoracic spiracles.

[3] M. drewseni is typically found in neotropical environments, primarily in South America.

This species has been seen in Guyana, Suriname, Venezuela, Brazil, Peru, Paraguay, Colombia, and Argentina.

[2] In these semi-urban environments, nests can be found under eaves of building, barns, or other protected places.

This process continues until the first eggs begin to hatch, at which point growth of the colony stops.

At this point the phenomenon of abortion of larvae and pupae occurs, more cells are abandoned, and the adult population decreases.

[3] M. drewseni nests typically have one main comb and tend to be, on average, 14 cells in diameter.

Pulp is utilized, as well, and can come from fence rails, planks, and dried cortex from stems from Verbenaceae, an herb plant.

The water serves as a type of glue, adhering the fibers of the nest material, beginning the formation of a ball.

The water also serves to moisten and soften the fibers of the pulp so it is easier to manipulate for the formation of the nest.

This stem is created from a combination of pulp filaments and secretions from the foundress’ oral cavity.

After this, she thickens the new formation, and then adds a shallow cup-shaped structure that will serve as a cell base.

Strangely, when workers approach with pulp, the larvae begin stretching, perhaps as a signal to show what cells are in most desperate need of heightening.

[5] Due to the prevalence and devastation of ant attacks, M. drewseni has developed a way to protect themselves, but mainly their brood, from their predators.

In addition, the structure of the nest itself and the morphology of the wasp seems to support a co-evolution of this defensive mechanism.

This system of defense is also very practical because it allows the female to forage and leave the brood unattended without putting them at risk.

For most, it lasted 14–16 days and temperature seemed to be the determining factor in shortening or lengthening the stage.

When compared to other wasps, the M. drewseni pupal stage is very stable and less prone to variation.

Compared to other wasp species, M. drewseni was much less aggressive and had many fewer dominance interactions.

This caste has also been observed to leave the nest for extended periods of time to either mate or forage for themselves.

Once they leave the nest, males tend to circulate where specific females are because of feeding and foraging opportunities.

ll captured prey tends to be fairly substantial in size (greater than 3 mm) but small enough that the wasp could chew the whole insect before returning to the nest.

This nectar is typically consumed from the buds and flowers of Althernanthera ficoidae, Hyptis atrorubens, and Clidemia hirta.