Females of P. atrimandibularis are unable to build a nest or produce workers, and therefore rely entirely on the host colony.

This paper wasp has enlarged mandibles, used as weapons to injure hosts that resist parasite intrusion.

They also have an enlarged first femur and a longer posterior tibia that is useful for when they must maintain a dominant position within the host colony.

Similar to the other Polistes social parasites, P. atrimandibularis usurps colonies in the late spring, which is roughly one month before the emergence of host workers.

[5] It is not until late summer that the newly emerged parasites migrate to the mountains to mate[5] and then overwinter for several months under a thick blanket of snow and ice.

[5] Once inseminated, females remain for overwintering for several months, under a thick blanket of snow and ice.

To ensure that they arrive and usurp their host colonies at the correct time, P. atrimandibularis postpone the overwintering exit.

However, after a few hours the female Polistes wasp will be able to recognize and identify the odor of the nest and create a template that it can refer to in the future.

While the other Polistes social parasites employ more aggressive tactics of usurping host colonies, P. atrimandibularis has a different approach.

Despite P. atrimandibularis passive strategy for usurping colonies, they still maintain morphological fighting characteristics to aid them in their aggressive behavior while pillaging secondary nests.

[3] The host species that P. atrimandibularis decides to invade, affects the size of the newly emerging parasites.

[7] By the time host workers emerge, they have already learned the modified colony chemical signature, containing both original and parasitic labels.