Baldfaced Hornet - Dolichovespula maculata
Family Vespidae -- hornets, paper wasps, potter wasps, yellowjackets
Live bald faced hornets (workers and queen) photographed in the wild at DuPage County, Illinois.
Hornet nest photographed at Oregon, Illinois, USA.

 

Baldfaced Hornet - Dolichovespula maculata
Bald-faced hornet worker (sterile female)

Bald-faced hornets are common in both wooded and urban areas. Queens start a new nest each spring after the weather warms up in late April or May. The queen finds loose bark, and other paper strips to start a small nest into which she places her eggs. She adds saliva to the paper bark and forms a smooth "carton."

Inside the carton are horizontal layers of comb or hornet cells divided into circular platforms. The outer carton shell is very thin. This means that if this nest is accidentally damaged from the outside by an animal, the paper covering is easily stripped away and a large number of angry, aggressive wasps fly directly toward the intruder and begin to sting. Since the sting is not barbed, a single hornet can deliver a series of painful stings. It is the venom in the sting that is the cause of the pain. Once a victim is stung, the best response is to distance oneself from the hornet nest as quickly as possible. In other words, "Run like hell." Multiple stings often occur close to a nest.

I have been stung multiple times by the Eastern Yellowjacket - Vespula maculifrons, but never by the bald-faced hornet. Of course, I was engaged in aggressive behavior toward their nest - I was trying to destroy it. I have been around thousands of bald-faced hornets in the wild, and they pay no attention to me whatsoever.

Since there is always a danger from anaphylactic shock from the venom of a hornet, it is good policy to leave pest control of colonies to a professional. Try to find hornet nests as soon as possible in the spring and summer because they only become larger and more aggressive with time. At the end of the season, the carton nest often remains hanging from a tree but the workers have all died out and the newly mated queens have left the nest to over-winter behind the bark of trees.

bald-faced hornet nest
This bald-faced hornet nest is about 10 inches in diameter

Baldfaced Hornet - Dolichovespula maculata

Baldfaced Hornet - Dolichovespula maculata
Baldfaced Hornet - Dolichovespula maculata
Dolichovespula maculata is not a true hornet; hornets belong to the genus Vespa.
Bald-faced hornets are actually wasps in the genus Vespula, many of which are commonly called yellowjackets.

Baldfaced Hornet - Dolichovespula maculata

Baldfaced hornets are black and white, heavy-bodied wasps about 1/2 - 3/4 inch long. They usually build exposed, grey nests in trees or shrubs. Occasionally, they will build nests under roof overhangs, in attics, crawlspaces and wall voids, or under decks or porches. The nests are constructed of a paper-like material formed from chewed wood, and may exceed the size of a basketball. These hornets are extremely quick-moving and wary.

Life cycle: In spring , the queens emerge from diapause and build small nests consisting of a few paper cells. 1 egg is laid in each cell. When the eggs hatch the female hunts other insects to feed to the larvae (although the queen pictured here devoured this moth herself and carried nothing home for the kids, so to speak). When larvae are fully grown, they spin silk cocoons inside their cells and pupate into adult wasps. The wasps that emerge from the cells are all sterile female workers, which then take over nest building and foraging duties.

Near the end of the summer, female larvae are fed greater amounts of food, which allows them to develop into queens, with complete reproductive systems. At the same time, the queen lays unfertilized eggs, which develop into male wasps. The males mate with the fertile females, and the colony breaks up with the onset of autumn. The fertilized females overwinter and the males die.

 

June , 2003 - Baldfaced Hornet queen attacks...  I just witnessed a macabre spectacle. I was out along the shore of a small pond near my house, and happened to see an enormous black and white hornet queen - much larger than a worker (sterile female).   I followed her about as she scouted amongst the low plants and grasses - and watched in amazement as she attacked, dismembered, and ate a yellow-collared scape moth in a matter of 2 minutes or so. The pictures above tell the tale.


Hornet Queen Attacks Scape Moth
Baldfaced Hornet - Dolichovespula maculata
Bald-faced hornets hang upside down while devouring prey. They feed the chewed insect parts to their larvae.