Bald-faced hornets: Amazing arboreal artists

As the leaves begin to exit the trees, I am shocked to see a large, grey, pear-shaped, nest nearly two feet tall, hanging near our house. I marvel at the fact that not only have I been walking beneath this impressive structure throughout the summer without noticing it, but I have not been harassed by the insects. Not once.

This nest belongs to a native species of yellow jacket known as the bald-faced hornet (Dolichovespula maculate). At ¾ inch in length, it is as impressive in size as it is in looks, sporting a nearly all-black body with a distinctive white (bald) face and three bands of white near the tip of the abdomen. But just how did this large abode come to appear right here, hidden behind the leaves?

Beginnings

In the spring, a female bald-faced hornet emerges from her overwintering site, perhaps behind a piece of bark or beneath a log. Within her, she carries eggs, fertilized the previous autumn. Her mission is to seek out a strategic spot in which to begin her arboreal nest.

She begins by constructing a small structure containing a dozen or so hexagonal cells, each in which she lays an egg. These eggs will provide the foundation for the entire colony. Upon hatching, she feeds the larva a variety of insects, tending to them constantly until they mature into infertile females.

These newly formed females immediately begin to enlarge the nest and tend to the eggs which the fertile female continues to deposit into the newly constructed cells. Thus, the cycle continues throughout the summer and as the nest enlarges, more and more wasps are produced.

At the nest’s peak, well over 400 members may exist. Scientists refer to such colonies as “eusocial” meaning that they are highly organized. The wasps’ survival depends on the specialized division of labor, and the success of the nest relies on the diligence of the entire colony.

Expansion

But just how is that large orb created? If you have ever examined one up close, or run your fingers over the exterior, you will be amazed to find that the nest is actually made of paper. Let it be known that wasps were making paper long before humans.

Each member of the working hive carefully selects and chews pieces of wood fiber. While chewing, starches in the insect’s saliva are combined to make a specialized wood pulp. This pulp is then deposited around the layers of developing larvae and slowly develops into a large ball.

Each type of wood fiber collected and chewed results in a different color creating incredibly beautiful patterns. As the layers of horizontal combs containing larvae grow within, so do the surrounding walls of the hive. Thus, a structure that may have been too small to notice early in the summer, becomes much more visible as the hive increases in size.

The end

Toward the end of summer, as temperatures begin to drop, the queen begins to lay additional eggs that will hatch out as drones. These male hornets will disperse to mate with the newly emerging females in other hives. In turn, these fertilized females will find a sheltered spot in which to ride out the winter and begin new colonies the following spring.

Normally, the first hard frost of autumn kills off all the workers, while the fertilized queens have already departed to find shelter. Just days after the colony dies, birds such as chickadees, titmice and woodpeckers anxiously pull the nest apart to gorge on the freshly deceased larvae remaining within.

Not everyone can find it in their heart to appreciate bald-faced hornets. After all, if the nest is disturbed in any way causing them to feel threatened, their aggressive, defensive nature can be quite dangerous.

Because of their social structure, wasps will work together to vigorously defend their nests and unlike honeybees, which can sting only once, the hornets can sting repeatedly, causing much pain and swelling.

If you happen to come across a hornet nest, simply leave it alone, and they are happy to return the favor. Of course, sometimes the insects locate their nest in a high-traffic area where a peace agreement can’t possibly be reached, thus the nest must be removed.

Folklore

You may have heard the folklore phrase: “See how high the hornet’s nest, ‘twill tell how high the snow will rest.” This was a way for old-timers to determine the severity of the upcoming winter.

A nest built low meant there would be little snow for the wasps to worry about, while a nest high up in the branches foretold of much snow to come. In all honesty, however, by the time winter rolls around, the occupants of the hive have long since passed away, leaving the empty nest to sway in the chilly winter winds.

Bald-faced hornets do have their respective place in the ecosystem. They are beneficial due to their predation on spiders, flies and caterpillars which they feed to their larvae. The adult wasps feed mainly on nectar and pollen, serving as important pollinators. Adult hornets are often considered an important food source as they are consumed by birds and other animals.

Like it or not, bald-faced hornets are part of our landscape. They are here to stay. And although they tend to illicit fear and hostility, it is hard not to feel a bit of admiration for their amazing handiwork as well as the organized way in which they work together to ensure the success of their species.