Bald-Faced Hornet

Dolichovespula maculata
Family

Vespidae (a wasp family) in the order Hymenoptera (ants, bees, wasps)

Description

A fairly large wasp that is primarily black, with white or ivory markings on the face, thorax and toward the tip of the abdomen. The wings are translucent dark brown.

In winter after leaf-fall, look up into trees for old nests, which are large, rounded, papery, and gray. The nests of this social insect are frequently seen in natural history displays. Unlike the wasps we usually call yellowjackets, this species is not yellow. Its larger size and black and ivory coloration make it easy to distinguish as a distinct type of social wasp.

Size

Length (excluding appendages): 1/2 to 3/4 inch (workers), 3/4 inch (queen)

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Photo of bald-faced hornet face as it peeks out from hole in nest
Bald-Faced Hornet Face

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Photo of bald-faced hornet nest
Bald-Faced Hornet Nest

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Photo of bald-faced hornet nest built on house
Bald-Faced Hornet Nest Built On House

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Photo of interior of bald-faced hornet nest showing paper layers
Bald-Faced Hornet Nest Interior, Showing Paper Layers

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Photo of opening to bald-faced hornet nest
Bald-Faced Hornet Nest Opening

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Photo of bald-faced hornet in nest, showing underside of wasp
Bald-Faced Hornet In Nest
Habitat and conservation

Nests of this species are built in trees and shrubs and are made of wood pulp (literally paper). These wasps chew wood, mixing it with starches in their saliva, and use this substance to construct the nest. Nests eventually have several layers of horizontal comb enclosed by an outer envelope, just as yellowjacket nests do. Each nest is begun in spring by a single overwintered queen. Late-summer nests may contain several hundred workers, as well as males and new queens.

Foods

Adults generally eat nectar from flowers, but they collect insects and other arthropods to chew up and feed to their growing larvae.

image of Bald-Faced Hornet Distribution Map
Distribution in Missouri

Statewide.

Status

These and other “eusocial” wasps represent a peak of insect social development. Each colony is a family, all descended from a single queen, which hibernates in a protected place, emerges in spring, and lays the eggs for the whole colony. Scientists describe the colonies of such social insects as “superorganisms,” as the division of labor is greatly specialized, individuals cannot survive on their own, and it takes the efforts of the entire colony in order to reproduce itself.

Life cycle

In spring the overwintering queen starts building the nest and lays her first eggs. She feeds these larvae, which become infertile female workers. Workers are the most commonly encountered, as they do most of the work outside the nest, while the queen specializes in egg-laying. As winter dawns, the queen lays eggs that become new queens and male drones. Once these mature and mate, and temperatures drop, all die except the fertilized young queens.

Human connections

Aggressive nest defense makes these wasps a stinging threat, but their foragers do not collect sweets or food scraps and are not aggressive away from the nest. Like all wasps, bald-faced hornets do much that benefits human interests and should not be destroyed indiscriminately.

Ecosystem connections

As predators, these wasps spend their days hunting many types of insects and spiders. As nectar eaters, they play a role in pollinating plants. And despite their formidable defensive capabilities, these wasps certainly can become food for numerous larger predators.