The term “black hornet” is a common but imprecise label that typically refers to one of two large insects found across North America. This designation most often describes the Bald-faced Hornet, which is technically a species of aerial yellowjacket, or the European Hornet, the only true hornet species established in the United States. Accurate identification relies on observing the insect’s size, specific color pattern, and the structure of the nest it builds.
Identifying the Bald-faced Hornet
The Bald-faced Hornet (Dolichovespula maculata) is easily recognized by its striking black and white coloration. This insect is predominantly black with distinct, ivory-white markings on its face, thorax, and the tip of the abdomen. Workers are robust, measuring between 12 and 20 millimeters in length. Despite its common name, the Bald-faced Hornet is classified as an aerial yellowjacket, not a true hornet, and has a generally smooth body surface.
Identifying the European Hornet
The European Hornet (Vespa crabro) is the only true hornet found in the United States and is noticeably larger than yellowjacket relatives. Workers can reach up to 25 millimeters long, while queens may exceed 35 millimeters. The head and thorax display a rusty reddish-brown or mahogany color, distinguishing them from the Bald-faced Hornet. The abdomen is marked with a pattern of yellow and brown stripes, where the brown markings often form tear-drop shapes extending into the yellow bands. This species also has a slightly hairier body texture compared to the Bald-faced Hornet.
Distinguishing Them From Other Large Wasps
The two insects commonly labeled as “black hornets” feature distinct coloration that separates them from other large wasps. Yellow jackets are generally smaller, rarely exceeding 15 millimeters, and exhibit bright black and yellow banding. The Cicada Killer wasp is sometimes mistaken for a hornet due to its size, but it is slenderer. It features a black abdomen marked with bright yellow splotches, a pattern different from the white markings of the Bald-faced Hornet or the brown and yellow of the European Hornet. The European Hornet is further distinguished by its reddish-brown head and thorax, a feature absent in most other common large wasps.
Unique Nest Structures and Locations
The nest construction and placement offer reliable clues for distinguishing between the two species.
Bald-faced Hornet Nests
Bald-faced Hornets build a large, striking paper nest that is aerial and completely exposed. These nests are gray, football-shaped, and suspended high in trees, large shrubs, or sometimes under the eaves of buildings. The nest material is a light, papery pulp with a layered outer shell and a single entrance hole typically located near the bottom.
European Hornet Nests
In contrast, the European Hornet prefers nesting in concealed, dark cavities, such as hollow trees, wall voids, or attics. Because the nest is hidden within an enclosed space, it often lacks the thick, protective outer envelope seen in the Bald-faced Hornet’s exposed structure. The material itself is a coarser, often tan or brown paper, and only a small entrance hole may be visible on the exterior of a structure or tree trunk.