Hornets are the largest of the eusocial wasps, and are similar in appearance to their close relatives yellowjackets. Some species can reach up to 5.5 cm (2.2 in) in length. They 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 is widely distributed throughout Europe, Russia, North America, and north-eastern Asia. Wasps native to North America in the genus Dolichovespula are commonly referred to as hornets, but all of them are actually yellowjackets.
The Vespidae are a large, diverse, cosmopolitan family of wasps, including nearly all the known eusocial wasps and many solitary wasps. Each social wasp colony includes a queen and a number of female workers with varying degrees of sterility relative to the queen. In temperate social species, colonies usually last only one year, dying at the onset of winter. New queens and males (drones) are produced towards the end of the summer, and after mating, the queens hibernate over winter in cracks or other sheltered locations. The nests of most species are constructed out of mud, but polistines and vespines use plant fibers, chewed to form a sort of paper. Many species are pollen vectors contributing to the pollination of several plants, being potential or even effective pollinators, while others are notable predators of pest insect species, and a few species are invasive pests.
Paper wasps are vespid wasps and typically refers to members of the vespid subfamily Polistinae, though it often colloquially includes members of the subfamilies Vespinae and Stenogastrinae, discussed elsewhere, 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 also sometimes called umbrella wasps, due to the distinctive design of their nests.
The Asian giant hornet or northern giant hornet, including the color form referred to as the Japanese giant hornet, is the world's largest hornet. It is native to temperate and tropical East Asia, South Asia, Mainland Southeast Asia, and parts of the Russian Far East. It was also found in the Pacific Northwest of North America in late 2019 with a few more additional sightings in 2020, and nests found in 2021, prompting concern that it could become an invasive species. However, by the end of the season in November 2022, there were no confirmed sightings in North America at all, suggesting they may have been eradicated in that region.
The European hornet is the largest eusocial wasp native to Europe. It is also the only true hornet found in North America, having been introduced to the United States and Canada from Europe as early as 1840. Vespines, such as V. crabro, are known for making intricate paper-like nests out of surrounding plant materials and other fibers. Unlike most other vespines, reproductive suppression involves worker policing instead of queen pheromone control, as was previously thought.
The Oriental hornet is a social insect species of the family Vespidae. It can be found in Southwest Asia, Northeast Africa, the island of Madagascar, the Middle East, Central Asia, and parts of Southern Europe. Oriental hornets have also been found in a few isolated locations such as Mexico and Chile due to human introduction. The Oriental hornet lives in seasonal colonies consisting of caste system dominated by a queen. The hornet builds its nests underground and communicates using sound vibrations. The hornet has a yellow stripe on its cuticle (exoskeleton), which can absorb sunlight to generate a small electrical potential, and this might help supply energy for digging. The adult hornet eats nectar and fruits and scavenges for insects and animal proteins to feed to its young. Because they are scavengers, the hornets may also serve as a transmitter of disease following consumption of infected plants. The hornets are a primary pest to honey bees, attacking bee colonies to obtain honey and animal proteins. The sting of an Oriental hornet can be quite painful to humans and some humans are allergic to stings.
The Polistinae is a subfamily of eusocial wasps belonging to the family Vespidae. They are closely related to the wasps 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.
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.
Polistes humilis, known as the Australian paper wasp, is a species of wasp in the family Vespidae that is found throughout Australia and which has been introduced to northern New Zealand. These paper wasps can be identified by their long thin legs and banded yellow and black coloring. They have been known to re-utilize old nests. While the species does not exhibit morphological class differences, there are distinct behavioral differences between queens and workers. In addition, the species is eusocial and benefits from relatedness between individuals. They are known for delivering a painful sting, especially when their nest is disturbed, a behavior that has been developed as a nest defense mechanism. While wasps are often viewed negatively, they play an important pollination role for many plants.
Vespa simillima, the yellow hornet, including the color form known as the Japanese hornet or Japanese yellow hornet (キイロスズメバチ), is a common hornet species in the Eastern Hemisphere. The typical mainland color form is darker and hairier than the yellow form; it lives in Hokkaido, the Korean Peninsula, Eastern Siberia and China, but is less common in Japan, where the yellow color form predominates. It should not be confused with the Asian giant hornet, which has a color form sometimes referred to as the "Japanese giant hornet". While there is a history of recognizing subspecies within many hornets, the most recent taxonomic revision treats all subspecific names in the genus Vespa as synonyms, effectively relegating them to no more than informal names for regional color forms.
Polistes carnifex, commonly known as the executioner wasp or executioner paper wasp, is a neotropical vespid wasp in the cosmopolitan genus Polistes.
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.
Polistes nimpha is a eusocial paper wasp found all over Europe, with particular sightings in Turkey, Finland, Estonia, and Latvia. It is also found in northern Africa, Pakistan, Iran, India, Kazakhstan, Mongolia, and China. The climate in these areas is relatively cold and snowy in the winter, while summers are usually hot and dry, with steppe vegetation. Polistes nimpha colonies are relatively small and easily manipulated.
Parischnogaster mellyi is a medium-sized species of a hover wasp in the family Vespidae. It is found in Southeast Asia and is widely spread in Thailand and Malaysia. Its nests feature flexible and dynamic qualities, and they are commonly seen under roofs of houses and huts in rural areas. Hovering and patrolling behaviors are the species’ main defining behavioral features, and such activities are closely linked to its mating patterns.
Polistes biglumis is a species of social wasp within Polistes, the most common genus of paper wasp. It is distinguished mainly by its tendency to reside in montane climates in meadows or alpine areas. Selection pressure from the wasp's environment has led to several idiosyncrasies of its behavior and lifecycle with respect to its relative species in the genus Polistes. It alone among paper wasps is often polyandrous. In addition, it has a truncated nesting season that gives rise to unique competitive dynamics among females of the species. P. biglumis wasps use an odor-based recognition system that is the basis for all wasp-to-wasp interaction of the species. The wasp's lifecycle is highly intertwined with that of Polistes atrimandibularis, an obligate social parasite wasp that frequently invades the combs of P. biglumis wasps.
Parischnogaster alternata, the black hover wasp, is a eusocial wasp in the genus Parischnogaster. It is native to South-East Asia, and builds its nests in cavities located in dark and damp locations. The nests of black hover wasps are often found in clusters, which serves as a passive defense mechanism against predators. The annual colony cycle begins with nest initiation by a single foundress though colonies typically consist of 2-3 associative females and helpers that aid in brood development, nest construction, and colony defense. Indicative of the name, female P. alternata are known to strategically hover near nests when visiting other colonies before landing. These intrusions produce responses ranging from aerial fighting to cooperative food sharing.
Polistes japonicus is a eusocial paper wasp found in Japan. It was first described by Henri Louis Frédéric de Saussure in 1858. It is closely related to Polistes formosanus. This species lives in small colonies with few workers and a foundress queen. Nests of these wasps are sometimes used as a traditional medicine in Korea, China, and Japan.
Vespa affinis, the lesser banded hornet, is a common hornet in tropical and subtropical Asia.
Polistes bahamensis is a large species of colourful paper wasp in the genus Polistes of the family Vespidae which occurs in the Bahamas, Florida and Louisiana. It is also said to occur in Georgia.
Van der Vecht's gland or Van der Vecht's organ is a gland which is located in an area of modified cuticle on the rearmost gastral sternite of female wasps. This gland secretes chemicals which are important in the determination and maintenance of the hierarchy of groups of eusocial wasps and are used in the defence of the nests in others. In the Asian giant hornet the Van der Vecht's gland is used to scent mark hives of honey bees to attract other members of their colony to cooperatively attack the hive; the only known case of the gland's use to scent mark a food source. In the cleptoparasitic paper wasp Polistes semenowi the female usurps the host foundress, usually Polistes dominula and uses an enlarged Van der Vecht's gland to produce large quantities of hydrocarbons and to control the host workers, and even sometimes the host foundress. The gland was discovered by, and named in honour of, the Dutch entomologist Jacobus van der Vecht.
