By Cara Fernandes
The bald-faced hornet (Dolichovespula maculata) is not actually a hornet, but a wasp! We don’t always think of wasps as pollinators. They are indeed pollinators, as well as predators of other insects and spiders, and therefore play an important role in our local ecosystems. As an aculeate wasp, they have a constricted waist, a stinger, and will feed on nectar from flowers, resulting in incidental pollination. Not only are they pollinators, but their predation on other insects helps control the damage that foliage & seed eating insects can cause to plants and crops. Bald-faced hornets will also scavenge from dead prey if resources are scarce. They particularly like the sap and fruit from birch trees.
To make their paper nest, the bald-faced hornet first collects water. Then, they will collect fibers from a source of wood (old buildings, fence posts, or dead wood in the forest) or plant fiber from dry grass stems. Using their mandibles, the wasp chews at the material and carries the mass back to the nest, mixing it with water and their mandibular gland secretions to adhere the material together. Their nests are grey in color and can be up to 24 inches in length.
Incredibly, each paper wasp nest is actually a family that is descended from just one queen! Solitary females that emerge in the spring will look for a place high above the ground in an open area near trees to start building her nest. The nest is then started by this one overwintered queen who begins building and lays the first infertile female workers. From that point, the nest grows to include several hundred worker wasps. Workers will continue to gather resources and build the nest while the queen focuses on egg laying inside the nest. At the end of the summer, the queen will lay eggs that will become new queens and male drones that will mate. All other wasps in the colony will die with cold winter temperatures except the newly fertilized queens who find a spot to spend the winter. They will not use the same nest year to year, as the nests will decompose once the winter starts. Since the nests are usually high above the ground, they pose little threat to people and should be left alone and appreciated for their value to the ecosystem.