P. austroccidentalis displays several morphological adaptations for parasitism such as increased mandible size and an enlarged Van der Vecht's organ.

[1] P. austroccidentalis is larger than most Polistes species, which initially caused it to be classified in a separate genus (Sulcopolistes).

During the winter, the wasps ascend to a higher altitude; in the spring, however, they descend to the lowlands to find host colonies.

Since P. austroccidentalis is unable to create nests and produce worker classes, it is completely dependent on a host colony to fulfill these functions.

[6] Because P. austroccidentalis normally attacks the host's nests just prior to worker emergence, it is surmised that such selection pressure might have impacted the developmental times in P. dominula to be shorter.

It would be advantageous for the hosts to make their brood developmental time to be shorter so that they can rapidly generate workers and defend their nests.

Over time, P. austroccidentalis has completely lost the ability to create its own worker class and has adopted a strategy of parasitism.

[6][3] The parasitic larvae display rapid growth, which allows P. austroccidentalis to optimize its rate of offspring production.

[3] Approaching the dominant host female, the parasite aggressively attacks her in an attempt to drive her out of the nest.

[2] Once she has entered the colony and subdued the dominant host female, the parasite immediately begins laying eggs.

Some time after the initial invasion – approximately thirty days – the hosts chemically recognize the parasites as their own species.

After this initial destruction, however, the P. austroccidentalis female does not attack any emerging host workers, and spends most of her time laying eggs.

As soon as a female P. austroccidentalis wasp enters a host nest, she begins to vigorously rub her abdomen against the comb.

[3] The hydrocarbons secreted by Polistes wasps are efficiently spread on to the cuticle by a structure called the Van der Vecht’s organ.

Since the Van der Vecht’s organ spreads hydrocarbons that enable P. austroccidentalis mimicry, increased size of the structure in this species most likely occurred as a result of selective pressure on the wasp due to the success of its parasitic life strategy.