Many people use “wasp” and “hornet” interchangeably, often unaware that hornets are a specific type of wasp. Their similar appearances and stinging capabilities cause this confusion. This article explores the biological relationship between wasps and hornets, highlighting their different physical traits, behaviors, and nesting habits.
Understanding the Relationship
The core distinction between wasps and hornets lies in their taxonomic classification: all hornets are wasps, but not all wasps are hornets. Wasps represent a vast and diverse group of insects, encompassing over 100,000 known species globally. They are members of the order Hymenoptera, which also includes bees and ants. Within this broad order, wasps belong to various families, but hornets are specifically classified under the genus Vespa within the family Vespidae.
The family Vespidae includes social wasps like yellowjackets and paper wasps, alongside hornets. Only about 22 species of true hornets (genus Vespa) are recognized worldwide, with most native to tropical Asia. The European hornet (Vespa crabro) is the only true hornet species widely established in North America, having been introduced in the 19th century.
Distinctive Physical Traits
Hornets generally exhibit a more robust and larger build compared to many other wasp species. True hornets, such as the European hornet, can measure between 0.75 to 1.5 inches (about 1.9 to 3.8 cm) in length, while some Asian species, like the Asian giant hornet (Vespa mandarinia), can reach up to 2 inches (5 cm) or more. In contrast, many common wasps, like yellowjackets, typically range from 0.5 to 1 inch (about 1.2 to 2.5 cm). Hornets tend to have a wider, more robust body and a fuller abdomen, contributing to their more “chubby” or “heavyset” appearance. Wasps, conversely, often possess a more slender, elongated body with a noticeably narrower waist.
Coloration also provides visual cues, though variations exist between species. European hornets typically display reddish-brown coloring with yellow or orange and black markings on their abdomen, and sometimes on their heads. Many wasps, particularly yellowjackets, are recognized for their brighter, more distinct black and yellow stripes. The head of a true hornet is typically larger and more prominent, often with a wider top margin, compared to the smaller heads of most other wasps.
Behavioral and Nesting Differences
Hornets and other wasps exhibit distinct behavioral patterns and nesting preferences. Hornets are primarily predatory insects, often preying on larger insects like grasshoppers, beetles, and even other wasps or honeybees to feed their larvae. While adult hornets consume sugary substances like nectar, tree sap, and fruit juices, they are less likely to scavenge around human food or garbage compared to many wasps. Wasps, particularly yellowjackets, have a more varied diet, acting as both predators of smaller insects and opportunistic scavengers, frequently found near picnics and trash cans in search of sweets and proteins.
Regarding aggression, hornets are generally less aggressive than some wasp species, especially yellowjackets, unless their nest is disturbed. They are highly territorial around their nests and will fiercely defend them, stinging repeatedly if they perceive a threat. Yellowjackets, however, are known for higher aggression levels, especially in late summer when food sources dwindle, and may sting with less provocation.
Hornets construct large, papery, enclosed nests by chewing wood fibers and mixing them with saliva. These nests are often spherical or teardrop-shaped and can grow quite large, sometimes reaching the size of a basketball. True hornets typically build their nests in sheltered, elevated locations such as hollow trees, wall voids, attics, or hanging from tree branches and eaves. In contrast, other social wasps display diverse nesting habits: paper wasps build open, umbrella-shaped nests with visible cells under eaves, while yellowjackets often build their nests underground in abandoned rodent burrows or in concealed cavities like wall voids.
Why Misidentification Occurs
Misidentification between wasps and hornets is common due to several factors, including overlapping appearances and generalized common names. The broad term “wasp” encompasses a vast number of species, many of which share the familiar black and yellow coloration often associated with stinging insects. This visual similarity leads many to mistakenly label any black and yellow stinging insect as a hornet, even if it is a type of wasp. Yellowjackets, for instance, are frequently confused with hornets due to their aggressive tendencies and similar color patterns, despite being smaller and having different nesting habits.
Regional common names further exacerbate this confusion. A prime example is the “bald-faced hornet” (Dolichovespula maculata), which is not a true hornet (genus Vespa) but rather a type of yellowjacket. This species is named a “hornet” primarily because it builds large, aerial, enclosed paper nests, similar to those of true hornets, rather than the subterranean nests common to many yellowjackets. The distinctive black and white markings of the bald-faced hornet also set it apart from the typical yellow and black patterns of most yellowjackets and hornets, adding another layer of visual complexity.