With the arrival of Independence Day, one of my favorite pastimes is to sit on the front stoop and watch the parade of pollinators and predators as they work their magic in my bed of perennial flowers. Perched on the stoop is a stump from an old black locust tree that serves as a base for a flowerpot full of wine colored periwinkles. An uneven cut on the top of the stump creates a small crack beneath the flowerpot and as I watched, an impressive yellow and black wasp zipped by my face and disappeared into the crack. Foolish curiosity guides many of my actions and when I removed the flowerpot, I discovered a cavity in the locust stump occupied by a thriving colony of the paper wasp, Polistes dominulus, a.k.a the European paper wasp. In previous episodes, we visited frightening wasps such as yellow jackets and painful stingers such as the bald-faced hornet. Like these predators, the European paper wasp spends most of its time in highly beneficial pursuits such as hunting small caterpillars in the garden.
A guard keeps a watchful eye on the bug guy.
Nests of the paper wasp are founded in spring by one or more founding-females that survived the rigors of winter in a protected location, perhaps under the lose bark of a tree. Often, females will return to the nesting site that was the place of their birth to build a new nest. In species of paper wasps where a single female founds a nest, the foundress lays eggs and cares for a brood of sterile workers destined to help her raise their sisters until males and new reproductive females are produced later in the year. In other species of paper wasps, more than one reproductively competent female may found a colony and this is where the trouble begins. Shortly after the colony is established, founding females engage in highly aggressive contests to determine who will earn the right to reproduce and populate the colony with offspring. These encounters are called falling fights as females sometimes tumble to the ground while they wrestle, bite, and sting each other. Falling fights are brutal and sometimes result in death of the loser. In many species of paper wasps, the dominant foundress maintains order in the colony by chasing, biting, and otherwise harassing subordinate foundresses. In other species including the dominulus paper wasp, the order of rule may be more subtle. The dominant female may selectively eat eggs of her subordinate nest mates should they be so bold as to attempt reproduction. Having demonstrated her mettle, the dominant foundress gains the privilege of populating the colony with her young while the other foundresses wait in the wings tending the nest. If a bird should come along and eat the ruling tyrant, a subordinate female may ascend to the throne and establish a new reign of tyranny. Subordinate foundresses may attempt to usurp the power with the dominant foundress in battle, but often the seated foundress is the victor.
In addition to dramatic confrontations, paper wasps engage a variety of behaviors involving vibrations of the body, wagging of the abdomen, and drumming of the antennae. Although the meaning of these actions is not entirely understood, they are thought to be ways that adults communicate with developing larvae to gage their hunger level or inform them that dinner is about to be served. Furthermore, some of these behaviors may help the dominant foundress direct activities of her nest mates such as foraging for food or pulp or suppress unruly behaviors of her subordinates. My intrusive ogling and photography provoked nothing more than inquisitive stares from the wasps in my log. However later in summer, my small colony of wasps will grow to many dozens and it may be time to relocate the stump or risk a surprising close encounter of a Polistes kind.
References
The wonderful reference “The Biology of Wasps” by Kenneth Ross and Robert Matthews was used as a reference for this episode.
To learn more about the European paper wasp, please visit the following web sites: