Bald-faced Hornet Nests Vulnerable
As mentioned in a previous post (https://naturallycuriouswithmaryholland.wordpress.com/2023/04/28/bald-faced-hornet-queens-soon-to-emerge-from-hibernation/ ) young Bald-faced Hornet queens are the only individuals in a nest to overwinter. Once they have emerged from hibernation, queens begin building a new nest. Most of us are familiar with hornets’ large, globular nests that reach a foot or more in length, but it takes many hornets and many weeks for them to attain this size.
Initially the queen constructs three or four paper-mache-like cells that are surrounded by a very thin paper envelope. After she constructs this miniature nest, the queen lays an egg in each of the cells, and continues to enlarge the nest. When the first eggs hatch, the queen feeds the larvae while continuing to construct more cells and lay more eggs. When the larvae pupate and emerge as adult workers, they take over the task of enlarging the nest and rearing the larvae. From this point on, the queen’s sole task is to lay eggs.
The starter nest which the queen constructs is tiny – the outer envelope is a mere inch in diameter. It is extremely delicate and vulnerable at this stage due to its light weight. Strong winds can easily detach the nest from the branch it’s attached to. This is the time of year when it is possible to find miniature hornet nests littering the forest floor.
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.
Bald-faced Hornet Queens Soon To Emerge From Hibernation
Bald-faced Hornets (Dolichovespula maculata) are a species of wasp, named for the white (“bald”) markings on their heads. Known for their large, hanging paper nests, most of these insects have a relatively short life – no longer than the span of a summer. Four to seven hundred hornets, mostly female workers in addition to one queen, occupy the nest all summer.
Come late summer/early fall the sole egg-laying queen begins to lay eggs that become drones (males) and new queens. When mature, these fertile males and queens fly off to mate. The drones and the female workers in the nest then die; the old queen, if not killed by workers, dies with them around mid-autumn. The fertilized young queens hibernate over winter in rotting logs, under bark and in crevices, and start new colonies in the spring of the following year. A recent exploration of a rotting log revealed that bald-faced hornet queens are not active yet, but soon will be. (Photo: Bald-faced Hornet queen)
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.
Bohemian Waxwings Dining On Bald-faced Hornet Larvae
We think of Bohemian Waxwings, colorful winter visitors, as primarily consumers of sugary fruits, but their diet is not exclusively frugivorous. They (and Cedar Waxwings) eat sap drips in the spring and aerial insects, especially emergent aquatic species, in the summer.
During the winter, in addition to fruits, Bohemian Waxwings also feed on protein-rich foods when they are available. Pictured is one of many Bohemian Waxwings that found a goldmine of protein — dead Bald-faced Hornet larvae. While the hornet queen overwinters under loose bark or a similarly protected area, the larvae that are developing within the nest when a hard frost hits are killed. Bohemian Waxwings apparently recognize this rich source of protein. Scale insects and tree buds (American Elm and ash species) are also consumed in the winter and spring. (Photograph by Terry Marron)
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.
Drama In The Goldenrod Patch
At this time of year when most flowers have gone by, Canada Goldenrod (Solidago canadensis) is a primary source of pollen and nectar for bees, beetles, butterflies, flies and many other insects. Consequently, goldenrod flowers are a popular place for insect-eating predators to linger.
Recently I spied an Ambush Bug that had captured a fly and had its proboscis inserted into it, contentedly sucking away the fly’s innards while I photographed it. Unbeknownst to me or the Ambush Bug, another predator, a Bald-faced Hornet, had spied the bug with its prey. Although adult hornets consume liquids, usually sugars like the juice of fruits or nectar, their larvae are raised on a diet of insects, so adults are constantly looking for prey. Suddenly, out of nowhere, the hornet flew in, tussled with the Ambush Bug and flew off with the fly in its mandibles, landing on a nearby branch with the object of its thievery.
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.
Bald-faced Hornet Queens Laying Specialized Eggs
A Bald-faced Hornet colony begins in the spring when a queen emerges from winter hibernation. The queen builds a small nest, creates a few brood cells within the nest, deposits eggs in them and feeds the larvae when they hatch. These larvae are female workers — they will continue the nest building, food collection, feeding the larvae and protecting the nest while the queen concentrates on laying eggs.
During the summer the colony (and size of the nest) grows until there are between 100 to 400 workers. Toward the end of the summer the queen lays two special types of eggs. The first will be, like the workers’ eggs, fertilized eggs that will develop into females, but these females will be fertile (and develop into queens). The second group of eggs will be unfertilized eggs. These eggs will develop into fertile males. The maturation and emergence of the new queens and the fertile males marks the end of the functioning of the colony. At this point the workers are not replaced and die out. The ruling queen, having served her purpose, also dies. The newly-emerged adults (queens and fertilized males) leave the nest, mate, and the fertilized queens overwinter and begin their colony cycle all over again in the following spring. Some small nests complete their cycle by mid-September, while some large nests are still going strong until the cold kills the larvae in late November.
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.
The Architecture of a Bald-faced Hornet Nest
The exterior of a Bald-faced Hornet nest consists of an outer envelope of paper that is made up of a myriad of horizonal stripes of chewed up wood fibers that have been mixed with hornet saliva. Each stripe represents a single hornet’s contribution. The different colors represent different sources of wood. This outer envelope is only one of several (up to 12 or more) that serve to insulate the innermost, active part of the nest.
Inside these outer sheets are three or four horizontal tiers of hexagonal cells in which eggs are laid and brood are raised. Access from one level to another is at the periphery of the tiers, just inside the shell. The queen begins the nest, building a few cells and raising female workers that then take over the cell-building while the queen continues to lay eggs. As the number of hornets increases, so does the number of cells they build, and as a result the tiers become wider and wider. When space runs out, the hornets remove one or more of the innermost layers of insulating paper that form the envelope, while constructing new sheets on the outside. The nest continues to grow in this fashion until the queen’s egg-laying slows down at the end of the season.
The construction of these tiers of cells takes place upside down in total darkness, which is, in itself, quite a feat. When they are constructing a cell, the hornets keep one antenna inside the cell and the other on the outside. By monitoring the distance between the two antennae tips they can judge thickness of the wall. They do a similar thing with their mandibles, with one on each side of the wall, in order to straighten the cell walls and squeeze the pulp flat to remove water.
If the cells were built sideways or upwards they would require constant attention from the hornets until they dried in order to prevent them from sagging. Given that the cells are downward-facing, one might wonder why the hornet larvae don’t fall out. Water has a great affinity for uncoated paper (think of paper towels sucking up water against the pull of gravity). Because the larvae are damp, they actually stick to the paper cell walls. When they are ready to pupate, they must separate from the walls. They do this by attaching themselves to the cell with silk and then spin a silk cocoon.
In order to fully appreciate the intricate architecture of a Bald-faced Hornet nest, you must dissect one (they are only used for one season). Just be sure to wait until there have been a number of hard frosts, in order to assure that there are no residents. (Photo: Bald-faced Hornet nest – (left) envelope consisting of 12 layers & (right) cluster of cells it surrounded; inset: dissected inner section showing four tiers of cells)
Black Bears Raiding Brood
Previously this fall I posted about Black Bears foraging ferociously in the fall in order to store fat (sometimes doubling their weight) before hibernating. That post showed an ant-infested tree that had been ripped apart. As winter approaches, signs of bears’ frenetic gorging (hyperphagia) increase dramatically. Protein-rich sources such as Bald-faced Hornet nests (suspended from branches) and Yellow Jacket nests (in cavities in the ground) are highly sought after.
If you look closely, you’ll see that the claws of the bear that attempted to raid the hornet nest (suspended ten feet above the ground) were able to reach just the bottom portion of the nest, tearing the outer multi-layered, paper envelope but not reaching the brood-containing cells within. The Yellow Jacket cells containing brood (eggs, larvae and pupae), on the other hand, were all removed from the ground nest and consumed. All that remains is a portion of the outer envelope and a few adults.
Yellow Jackets On A Bender
At this time of year, yellow jackets, hornets and wasps take advantage of the plethora of fermented fruit that lies underneath fruit trees. Because the queen slows down the production of eggs in the fall, workers have time on their hands, as they have fewer larvae to collect food (chewed-up insects) for. Their life (but not the queen’s) is about to come to an end, and they go out in style. If you have observed these members of the Vespidae family acting more erratic, it may well be because they are drunk on hard cider. (Photo: yellow jackets binging)
Red-eyed Vireo Nests
The Red-eyed Vireo’s nest is indisputably a work of art. Unlike most songbird nests, it is suspended below the branch to which it is attached. Perhaps the observant eye of Arthur C. Bent, a compiler of firsthand bird observations in the early to mid-1900’s, describes it best.
“The red-eyed vireo builds a dainty little pensile nest suspended usually from a forking, horizontal branch of a tree, rather below the level of our eyes as we walk through second-growth. The nest is a beautifully finished piece of workmanship, constructed of fine grasses and rootlets, bits of birch bark, and paper from wasps’ nests, bound together and to the supporting branches with spider’s or caterpillar’s webbing, and , perhaps the most constant material, long, narrow, flexible strands of grapevine bark, which help to hold up the cup of the nest. “
As mentioned, pieces of Bald-faced Hornet nests are frequently incorporated into the outside of a Red-eyed Vireo’s nest. These papery bits of hornet nest are purely decorative, and serve no structural purpose. Hornets are aggressive and defend their nests vigorously, so much so that it is unusual to find birds nesting in close proximity to a hornet nest. A vireo nest covered with papery bits of a hornet’s nest looks very much like a young hornet nest. It is conceivable that the use of this decorative material is a strategy employed by vireos to ward off potential nest predators.
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.
Bald-faced Hornet Nests No Longer Inhabited (if you live where there has been a hard frost)
If you research bald-faced hornet nests you will find that their average size is often compared to that of a football or basketball. The maximum size is said to be between 14 and 18 inches in diameter, and up to 23 or 24 inches in length. The pictured nest (which hung 20 feet above the roof of my house) measures 14 inches wide and 29 inches long – far larger than the average hornet nest!
This entire nest was built in roughly four months. It was started by a queen bald-faced hornet that, after emerging from hibernation this past spring, chewed some wood fiber, mixed it with her saliva and created a few brood cells surrounded by one or more paper “envelopes.” She laid an egg in each cell, and fed the hornet larvae insects which she first masticated into tiny bits. When the larvae pupated and emerged as adult workers, they assumed the duties of nest building, food collection, feeding the larvae and protecting the nest, while the queen continued laying eggs in horizontal tiers of cells. This ongoing activity produced a colony of anywhere from 100 to 400 workers by the end of the summer. Shortly before the first hard frost this fall, the queen left the colony and found a protected spot in which to spend the winter. When freezing temperatures arrived, the workers all died, leaving a nest that will never again be inhabited by bald-faced hornets. (Thanks to Nick Burnham, who ingeniously managed to collect the nest for me, and Gary Trachier for the photo.)
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.
Black Bears Seeking Protein
Although insects and animal matter make up less than 10% of the annual black bear diet, they are a crucial part of it. Black bears get most of their animal protein from ant brood, hornet larvae, tent caterpillars, march fly larvae, grubs (especially June beetle grubs), and snow fleas. Among the most preferred sources are bee and hornet larvae. Berries and other fruit don’t have a great amount of protein, but they do have some (blackberries = 2 grams of protein per cup). If the summer berry crops fail, insect brood is especially important, especially at this time of year, when bears are seeking protein, fats and carbohydrates, putting on as much as 30 pounds per week to sustain themselves through the coming months of hibernation.
When tearing apart a beehive, yellow jacket nest or bald-faced hornet nest (see photo), bears do get stung, particularly on their ears and faces (their fur is fairly impenetrable). Apparently the reward is worth the aggravation. After filling themselves with brood (and in some cases, honey) black bears shake vigorously in order to rid themselves of any insects that are caught in their fur.(Thanks to Alfred Balch for photo op.)
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate”
button.
Hover Fly Mimics Bald-faced Hornet
Adult hover flies, often referred to as syrphid (family Syrphidae) or flower flies, feed on pollen and nectar, and are often seen hovering at or crawling on flowers. Many have black and yellow bands on their abdomen, and are frequently mistaken for bees. There are certain species of hover flies that mimic stinging wasps, including yellow jackets and bald-faced hornets (see photo). Predators such as birds, ambush bugs, and spiders might think twice about eating an insect that can sting, and hover flies take advantage of this. The process through which this occurs is called Batesian mimicry, and refers to when a harmless species evolves to imitate a harmful species that has the some of the same predators.
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.
Naturally Curious with Mary Holland 
What Other Naturally Curious People Are Saying