Yellowjacket in the context of Dolichovespula

A wasp is any insect of the narrow-waisted suborder Apocrita of the order Hymenoptera which is neither a bee nor an ant; this excludes the broad-waisted sawflies (Symphyta), which look somewhat like wasps, but are in a separate suborder. The wasps do not constitute a clade, a complete natural group with a single ancestor, as bees and ants are deeply nested within the wasps, having evolved from wasp ancestors. Wasps that are members of the clade Aculeata can sting their prey.

The most commonly known wasps, such as yellowjackets and hornets, are in the family Vespidae and are eusocial, living together in a nest with an egg-laying queen and non-reproducing workers. Eusociality is favoured by the unusual haplodiploid system of sex determination in Hymenoptera, as it makes sisters exceptionally closely related to each other. However, the majority of wasp species are solitary, with each adult female living and breeding independently. Females typically have an ovipositor for laying eggs in or near a food source for the larvae, though in the Aculeata the ovipositor is often modified instead into a sting used for defense or prey capture.

Hornets are wasps of the genus Vespa in the subfamily Vespinae (the vespine wasps). They are the largest of the eusocial wasps, with some species reaching 5.5 cm (2.2 in) in length. They are similar in appearance to their close relatives the yellowjackets, but are distinguished from other vespine wasps by the relatively large top margin of the head. Worldwide, 22 species of Vespa are recognized. Most species only occur in the tropics of Asia, though the European hornet (V. crabro) is widely distributed throughout Europe, Russia, North America, and north-eastern Asia. Wasps of the genus Dolichovespula native to North America are commonly referred to as hornets (e.g., bald-faced hornet), but are actually yellowjackets.

Like other social wasps, hornets build communal nests by chewing wood to make a papery pulp. Each nest has one queen, which lays eggs and is attended by workers that, while genetically female, cannot lay fertile eggs. Most species make exposed nests in trees and shrubs, but some (such as Vespa orientalis) build their nests underground or in other cavities. In the tropics, these nests may last year-round, but in temperate areas, the nest dies over the winter, with lone queens hibernating in leaf litter or other insulative material until the spring. Male hornets are docile and do not have stingers.

Vespula germanica, known colloquially as the European wasp, German wasp, or German yellowjacket, is a species of wasp found in much of the Northern Hemisphere, native to Europe, Northern Africa, and temperate Asia. It has spread and become well-established in many other places, including North America, South America (Argentina and Chile), Australia, South Africa, and New Zealand. German wasps are part of the family Vespidae and are sometimes mistakenly referred to as paper wasps because they build grey paper nests, although strictly speaking, paper wasps are part of the subfamily Polistinae. In North America, they are also known as yellowjackets.

The Polistinae is a subfamily of eusocial wasps belonging to the family Vespidae. They are closely related to the wasps (“yellowjackets” as they are called in North America) and true hornets of the subfamily Vespinae, containing four tribes. With about 1,100 species total, it is the second-most diverse subfamily within the Vespidae, and while most species are tropical or subtropical, they include some of the most frequently encountered large wasps in temperate regions.

The English common name for Polistinae is paper wasp. Many polistines, such as Polistes fuscatus, Polistes annularis, and Polistes exclamans, make their nests out of paper. Despite being called paper wasps, other wasps (including the wasps in the subfamily Vespinae) also build nests out of paper. Additionally, some epiponine wasps (such as Polybia emaciata) build their nests out of mud despite being Polistinae.

The subfamily Vespinae contains the largest and best-known groups of eusocial wasps, including true hornets (the genus Vespa), and the "yellowjackets" (genera Dolichovespula and Vespula). The remaining genus, Provespa, is a small, poorly known group of nocturnal wasps from Southeast Asia. One genus, Palaeovespa, has been described in the Paleocene to Eocene fossil records of North America and Europe. Collectively, the group can be found on all continents except Antarctica, and several of these wasps are invasive species, introduced beyond their native ranges, and can be major pests.

Vespula is a small genus of social wasps, widely distributed in the Northern Hemisphere. Along with members of their sister genus Dolichovespula, they are collectively known by the common name yellowjackets (or yellow jackets) in North America. Vespula species have a shorter oculomalar space (shown in the figure below right) and a more pronounced tendency to nest underground than Dolichovespula.

Dolichovespula arenaria, also known as the common aerial yellowjacket, sandhills hornet, and common yellow hornet, is a species of wasp within the genus Dolichovespula widely distributed in the North American continent.

Dolichovespula maculata is a species of wasp in the genus Dolichovespula and a member of the eusocial, cosmopolitan family Vespidae. It is taxonomically an aerial yellowjacket but is known by many colloquial names, primarily bald-faced hornet, but also including bald-faced aerial yellowjacket, bald-faced wasp, bald hornet, white-faced hornet, blackjacket, white-tailed hornet, spruce wasp, and bull wasp. Technically a species of yellowjacket wasp, it is not one of the true hornets, which are in the genus Vespa. Colonies contain 400 to 700 workers, the largest recorded colony size in its genus, Dolichovespula. It builds a characteristic large hanging paper nest up to 58 cm (23 in) in length. Workers aggressively defend their nest by repeatedly stinging invaders.

The bald-faced hornet is distributed throughout the United States and southern Canada, but is most common in the Southeastern United States. Males in this species are haploid and females are diploid. Worker females can, therefore, lay eggs that develop into males.

Paper wasps are a type of social vespid wasps. The term is typically used to refer to members of the vespid subfamily Polistinae, though it often colloquially includes members of the subfamilies Vespinae (hornets and yellowjackets) and Stenogastrinae, which also make nests out of paper.

Paper wasp nests are characterized by open combs with down pointing cells. Some types of paper wasps are occasionally referred to as umbrella wasps due to the distinctive design of their nests.

Hornets are wasps of the genus Vespa in the subfamily Vespinae (the vespine wasps). They are the largest of the eusocial wasps, with some species reaching 5.5 cm (2.2 in) in length. They are similar in appearance to their close relatives the yellowjackets, but are distinguished from other vespine wasps by the relatively large top margin of the head. Worldwide, 22 species of Vespa are recognized. Most species only occur in the tropics of Asia, though the European hornet (V. crabro) is widely distributed throughout Europe, Russia, North America, and north-eastern Asia. Wasps of the genus Dolichovespula native to North America are commonly called hornets (e.g., bald-faced hornet), but are actually yellowjackets.

Like other social wasps, hornets build communal nests by chewing wood to make a papery pulp. Each nest has one queen, which lays eggs and is attended by workers that, while genetically female, cannot lay fertile eggs. Most species make exposed nests in trees and shrubs, but some (such as Vespa orientalis) build their nests underground or in other cavities. In the tropics, these nests may last year-round, but in temperate areas, the nest dies over the winter, with lone queens hibernating in leaf litter or other insulative material until the spring. Male hornets are docile and do not have stingers.

Pseudomasaris is a genus of pollen wasps of the family Vespidae, found in arid regions of western North America. They feed their larvae on the pollen and nectar of a variety of plants, though many species prefer flowers in the genus Phacelia. They are colored black with yellow or white markings that, in a few species, resemble the coloration of yellowjackets.