Hornet
Encyclopedia
Hornets are the largest eusocial
wasp
s; some species can reach up to 5.5 cm (2.2 in) in length. The true hornets make up the genus Vespa and are distinguished from other vespines by the width of the vertex
(part of the head behind the eyes), which is proportionally larger in Vespa and by the anteriorly rounded gaster
s (the section of the abdomen
behind the wasp waist).
In Vespa crabro, the nest is founded in spring by a fertilized female known as the queen. It generally selects sheltered places like dark hollow tree trunks. It first builds a series of cells (up to 50) out of chewed tree bark. The cells are arranged in horizontal layers named combs, each cell being vertical and closed at the top. An egg is then laid in each cell. After 5–8 days, the egg hatches, and in the next two weeks, the larva undergoes its five stages. During this time, the queen feeds it a protein-rich diet of insects. Then, the larva spins a silk cap over the cell's opening and, during the next two weeks, transforms into an adult, a process called metamorphosis. Then, the adult eats its way through the silk cap. This first generation of workers, invariably females, will now gradually undertake all the tasks that were formerly carried out by the queen (foraging
, nest building, taking care of the brood
, etc.) with one exception: egg-laying
, which remains exclusive to the queen.
As the colony size
grows, new combs are added, and an envelope is built around the cell layers until the nest is entirely covered with the exception of an entry hole. At the peak of its population, the colony can reach a size of 700 workers, which occurs in late summer.
At this time, the queen starts producing the first reproductive individuals. Fertilized eggs develop into females (called "gynes" by entomologists), and unfertilized ones develop into males (sometimes called "drones"). Adult males do not participate in nest maintenance, foraging, or caretaking of the larvae. In early to mid-autumn, they leave the nest and mate during "nuptial flight
s". Males die shortly after mating. The workers and queens survive at most until mid to late autumn; only the fertilized queens survive over winter.
Other temperate species (e.g. the Yellow hornet, V. simillima, or the Oriental hornet
, V. orientalis) have similar cycles. In the case of tropical species (e.g., V. tropica), life histories may well differ, and in species with both tropical and temperate distributions (such as the Asian giant hornet
, Vespa mandarinia), it is conceivable that the cycle depends on latitude.
used to kill prey and defend nests. Hornet stings are more painful to humans than typical wasp stings because hornet venom contains a large amount (5%) of acetylcholine
. See Schmidt Sting Pain Index
. Individual hornets can sting multiple times; unlike typical bees
, hornets and wasps do not die after stinging because their stingers are not barbed and are not pulled out of their bodies.
The toxicity of hornet stings varies according to hornet species; some deliver just a typical insect sting, while others are among the most venomous known insects. Single hornet stings are not in themselves fatal, except sometimes to allergic victims. Multiple stings by non-European hornets may be fatal because of highly toxic species-specific components of their venom. The stings of the Asian giant hornet
(Vespa mandarinia japonica) are the most venomous known.
People who are allergic to wasp venom are also allergic to hornet stings. Allergic reactions are commonly treated with epinephrine
(adrenaline) injection using a device such as an EpiPen, with prompt followup treatment in a hospital. In severe cases, allergic individuals may go into anaphylactic shock
and die unless treated promptly.
is released in case of threat to the nest, and to mark prey, such as bees. Three biologically active chemicals: 2-pentanol, 3-methyl-1-butanol, and 1-methylbutyl 3-methylbutanoate, have been identified. In field tests, 2-pentanol alone triggered mild alarm and defensive behavior, but adding the other two compounds much exacerbated aggressiveness in a synergistic
effect.
If a hornet is killed near a nest it may release pheromone which can cause the entire nest to attack. Materials that come in contact with pheromone, such as clothes, skin, and dead prey or hornets, can also trigger an attack, as can certain food flavorings, such as banana and apple flavorings, and fragrances which contain C5 alcohols and C10 esters.
While taxonomically well-defined, there may be some ambiguity about the differences between hornets and other wasps of the family Vespidae, specifically the yellow jackets, which are members of the same subfamily. Yellow jackets are generally smaller than hornets and are bright yellow and black, whereas hornets may often be black and white—see wasp and bee characteristics
.
Another major difference between yellow jackets and hornets is each of their food choices and aggression towards humans. In autumn, yellow jackets may be attracted to human foods and food wastes, increasing potentially aggressive contact between yellow jackets and humans. Hornets, on the other hand, tend to stick to live insects.
Some other large wasps are sometimes referred to as hornets, most notably the bald-faced hornet
(Dolichovespula maculata) found in North America. It is set apart by its black and ivory coloration. The name "hornet" is used for this and related species primarily because of their habit of making aerial nests (similar to the true hornets) rather than subterranean nests. Another example is the Australian hornet
(Abispa ephippium), which is actually a species of potter wasp
.
Eusociality
Eusociality is a term used for the highest level of social organization in a hierarchical classification....
wasp
Wasp
The term wasp is typically defined as any insect of the order Hymenoptera and suborder Apocrita that is neither a bee nor an ant. Almost every pest insect species has at least one wasp species that preys upon it or parasitizes it, making wasps critically important in natural control of their...
s; some species can reach up to 5.5 cm (2.2 in) in length. The true hornets make up the genus Vespa and are distinguished from other vespines by the width of the vertex
Vertex (anatomy)
In arthropod and vertebrate anatomy, the vertex refers to the upper surface of the head.In humans, the vertex is formed by four bones of the skull: the frontal bone, the two parietal bones, and the occipital bone...
(part of the head behind the eyes), which is proportionally larger in Vespa and by the anteriorly rounded gaster
Gaster
The gaster is the bulbous posterior portion of the metasoma found in Apocrita Hymenoptera . This begins with abdominal segment III on most ants, but some make a postpetiole out of segment III, in which case the gaster begins with abdominal segment IV....
s (the section of the abdomen
Abdomen
In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...
behind the wasp waist).
Life cycle
Foraging
- Definitions and significance of foraging behavior :Foraging is the act of searching for and exploiting food resources. It affects an animal's fitness because it plays an important role in an animal's ability to survive and reproduce...
, nest building, taking care of the brood
Brood (honeybee)
In entomology, the term brood is used to refer to the embryo or egg, the larva and the pupa stages in the life of holometabolous insects. The brood of honey bees develops within a bee hive. In man-made, removable frame hives, such as Langstroth hives, each frame which is mainly brood is called a...
, etc.) with one exception: egg-laying
Oviposition
Oviposition is the process of laying eggs by oviparous animals.Some arthropods, for example, lay their eggs with an organ called the ovipositor.Fish , amphibians, reptiles, birds and monetremata also lay eggs....
, which remains exclusive to the queen.
Group size measures
Many animals, including humans, tend to live in groups, herds, flocks, bands, packs, shoals, or colonies of conspecific individuals. The size of these groups, as expressed by the number of participant individuals, is an important aspect of their social environment...
grows, new combs are added, and an envelope is built around the cell layers until the nest is entirely covered with the exception of an entry hole. At the peak of its population, the colony can reach a size of 700 workers, which occurs in late summer.
At this time, the queen starts producing the first reproductive individuals. Fertilized eggs develop into females (called "gynes" by entomologists), and unfertilized ones develop into males (sometimes called "drones"). Adult males do not participate in nest maintenance, foraging, or caretaking of the larvae. In early to mid-autumn, they leave the nest and mate during "nuptial flight
Nuptial flight
Nuptial flight is an important phase in the reproduction of most ant, termite and some bee species. During the flight, virgin queens mate with males and then land to start a new colony, or, in the case of honey bees, continue the planned succession of an existing hived colony.- Before the flight :A...
s". Males die shortly after mating. The workers and queens survive at most until mid to late autumn; only the fertilized queens survive over winter.
Other temperate species (e.g. the Yellow hornet, V. simillima, or the Oriental hornet
Oriental hornet
The Oriental hornet Vespa orientalis, is a hornet which looks very similar to the European hornet. It should not be confused with the Asian giant hornet ....
, V. orientalis) have similar cycles. In the case of tropical species (e.g., V. tropica), life histories may well differ, and in species with both tropical and temperate distributions (such as the Asian giant hornet
Asian giant hornet
The Asian giant hornet , including the subspecies Japanese giant hornet , colloquially known as the yak-killer hornet, is the world's largest hornet, native to temperate and tropical Eastern Asia...
, Vespa mandarinia), it is conceivable that the cycle depends on latitude.
Stings
Hornets have stingsStinger
-Biology:* Stinger, an organ or body part found in various animals that usually delivers some kind of venom.* Stinger , a minor neurological injury suffered by athletes.-Sports and entertainment:...
used to kill prey and defend nests. Hornet stings are more painful to humans than typical wasp stings because hornet venom contains a large amount (5%) of acetylcholine
Acetylcholine
The chemical compound acetylcholine is a neurotransmitter in both the peripheral nervous system and central nervous system in many organisms including humans...
. See Schmidt Sting Pain Index
Schmidt Sting Pain Index
The Schmidt Sting Pain Index is a pain scale rating the relative pain caused by different Hymenopteran stings. It is mainly the work of Justin O. Schmidt, an entomologist at the Carl Hayden Bee Research Center in Arizona...
. Individual hornets can sting multiple times; unlike typical bees
Honey bee
Honey bees are a subset of bees in the genus Apis, primarily distinguished by the production and storage of honey and the construction of perennial, colonial nests out of wax. Honey bees are the only extant members of the tribe Apini, all in the genus Apis...
, hornets and wasps do not die after stinging because their stingers are not barbed and are not pulled out of their bodies.
The toxicity of hornet stings varies according to hornet species; some deliver just a typical insect sting, while others are among the most venomous known insects. Single hornet stings are not in themselves fatal, except sometimes to allergic victims. Multiple stings by non-European hornets may be fatal because of highly toxic species-specific components of their venom. The stings of the Asian giant hornet
Asian giant hornet
The Asian giant hornet , including the subspecies Japanese giant hornet , colloquially known as the yak-killer hornet, is the world's largest hornet, native to temperate and tropical Eastern Asia...
(Vespa mandarinia japonica) are the most venomous known.
People who are allergic to wasp venom are also allergic to hornet stings. Allergic reactions are commonly treated with epinephrine
Epinephrine
Epinephrine is a hormone and a neurotransmitter. It increases heart rate, constricts blood vessels, dilates air passages and participates in the fight-or-flight response of the sympathetic nervous system. In chemical terms, adrenaline is one of a group of monoamines called the catecholamines...
(adrenaline) injection using a device such as an EpiPen, with prompt followup treatment in a hospital. In severe cases, allergic individuals may go into anaphylactic shock
Anaphylaxis
Anaphylaxis is defined as "a serious allergic reaction that is rapid in onset and may cause death". It typically results in a number of symptoms including throat swelling, an itchy rash, and low blood pressure...
and die unless treated promptly.
Attack pheromone
Hornets, like many social wasps, can mobilize the entire nest to sting in defense, which is highly dangerous to animals, including humans. The hornet attack pheromonePheromone
A pheromone is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting outside the body of the secreting individual to impact the behavior of the receiving individual...
is released in case of threat to the nest, and to mark prey, such as bees. Three biologically active chemicals: 2-pentanol, 3-methyl-1-butanol, and 1-methylbutyl 3-methylbutanoate, have been identified. In field tests, 2-pentanol alone triggered mild alarm and defensive behavior, but adding the other two compounds much exacerbated aggressiveness in a synergistic
Synergy
Synergy may be defined as two or more things functioning together to produce a result not independently obtainable.The term synergy comes from the Greek word from , , meaning "working together".-Definitions and usages:...
effect.
If a hornet is killed near a nest it may release pheromone which can cause the entire nest to attack. Materials that come in contact with pheromone, such as clothes, skin, and dead prey or hornets, can also trigger an attack, as can certain food flavorings, such as banana and apple flavorings, and fragrances which contain C5 alcohols and C10 esters.
Hornets and other Vespidae
Characteristics of common wasps and bees
While easily confused at a distance or without close observation, there are many different characteristics of common large bees and wasps which can be used to identify them.-External links:* * *...
.
Another major difference between yellow jackets and hornets is each of their food choices and aggression towards humans. In autumn, yellow jackets may be attracted to human foods and food wastes, increasing potentially aggressive contact between yellow jackets and humans. Hornets, on the other hand, tend to stick to live insects.
Some other large wasps are sometimes referred to as hornets, most notably the bald-faced hornet
Bald-faced hornet
Dolichovespula maculata is a North American insect commonly called the bald-faced hornet...
(Dolichovespula maculata) found in North America. It is set apart by its black and ivory coloration. The name "hornet" is used for this and related species primarily because of their habit of making aerial nests (similar to the true hornets) rather than subterranean nests. Another example is the Australian hornet
Australian hornet
The Australian hornet is a vespid insect native to the Australian Capital Territory, New South Wales, Northern Territory, Queensland and Western Australia states of Australia. The Australian hornet is a solitary insect, forming small nests against buildings and other structures...
(Abispa ephippium), which is actually a species of potter wasp
Potter wasp
Potter wasps are a cosmopolitan wasp group presently treated as a subfamily of Vespidae, but sometimes recognized in the past as a separate family, Eumenidae.-Recognition:...
.
Species
- Vespa affinis
- Vespa analis
- Vespa auraria
- Vespa basalis
- Vespa bellicosa
- Vespa bicincta
- Vespa bicolorVespa bicolorThe Black shield wasp is a species of hornet which has been found to be the pollinator of an orchid, Dendrobium sinense, found only on the Chinese island of Hainan. Vespa bicolor preys on honeybees which it feeds to its larvae....
- Vespa binghami
- Vespa crabro
- †Vespa dasypodia
- Vespa ducalis
- Vespa dybowskii
- Vespa fervida
- Vespa fumida
- Vespa luctuosaVespa luctuosaVespa luctuosa is a species of hornet which is endemic to the Philippines. The main subspecies is Vespa luctuosa luctuosa . Other known subspecies include Vespa luctuosa luzonensis and Vespa luctuosa negrosensis...
- Vespa mandarinia
- Vespa mocsaryana
- Vespa multimaculata
- Vespa orientalis
- Vespa philippinensis
- Vespa simillimaVespa simillimaThe Yellow hornet , including the subspecies known as the is a common hornet species in the Eastern Hemisphere. It should not be confused with the Asian giant hornet , which is sometimes referred to as the Japanese giant hornet, a subspecies of the former.-Predators:Along with other insects in...
- Vespa soror
- Vespa tropica
- Vespa velutina
- Vespa vivax
Notable species
- Asian giant hornetAsian giant hornetThe Asian giant hornet , including the subspecies Japanese giant hornet , colloquially known as the yak-killer hornet, is the world's largest hornet, native to temperate and tropical Eastern Asia...
Vespa mandarinia- Vespa mandarinia japonica (sometimes known as Japanese giant hornet) - the largest wasp, and the most venomous known insect (per sting).
- Asian predatory waspAsian predatory waspThe Asian predatory wasp is a species of hornet which preys on bees, grows up to about 2.5 cm long, native to China, with characteristic yellow legs. Hornets build nests, with several thousand individuals associated with one nest...
Vespa velutina - Black-bellied hornet Vespa basalis
- Black shield waspVespa bicolorThe Black shield wasp is a species of hornet which has been found to be the pollinator of an orchid, Dendrobium sinense, found only on the Chinese island of Hainan. Vespa bicolor preys on honeybees which it feeds to its larvae....
Vespa bicolor - European hornetEuropean hornetThe European hornet Vespa crabro, commonly known simply as the "hornet", is the largest European eusocial wasp. The queen measures 25 to 50 mm long; males and workers are smaller...
Vespa crabro, (sometimes known as Old World Hornet, or Brown Hornet). - Greater banded hornetGreater banded hornetGreater banded hornet is a tropical species of hornet found in Southeast Asia, from Afghanistan to New Guinea. It is medium sized, worker's length is of about 25 mm. The head is dark brown/red, the abdomen is black with a large yellow stripe.-External links:**...
Vespa tropica - Japanese hornet Vespa simillima (sometimes known as Japanese yellow hornet).
- Lesser banded hornet Vespa affinis
- Oriental hornetOriental hornetThe Oriental hornet Vespa orientalis, is a hornet which looks very similar to the European hornet. It should not be confused with the Asian giant hornet ....
Vespa orientalis - Vespa luctuosaVespa luctuosaVespa luctuosa is a species of hornet which is endemic to the Philippines. The main subspecies is Vespa luctuosa luctuosa . Other known subspecies include Vespa luctuosa luzonensis and Vespa luctuosa negrosensis...
the most lethal wasp venom (per volume).
See also
- Australian hornetAustralian hornetThe Australian hornet is a vespid insect native to the Australian Capital Territory, New South Wales, Northern Territory, Queensland and Western Australia states of Australia. The Australian hornet is a solitary insect, forming small nests against buildings and other structures...
- Bald-faced hornetBald-faced hornetDolichovespula maculata is a North American insect commonly called the bald-faced hornet...
- Bee-eaterBee-eaterThe bee-eaters are a group of near-passerine birds in the family Meropidae. Most species are found in Africa and Asia but others occur in southern Europe, Australia, and New Guinea. They are characterised by richly coloured plumage, slender bodies, and usually elongated central tail feathers...
- Characteristics of common wasps and beesCharacteristics of common wasps and beesWhile easily confused at a distance or without close observation, there are many different characteristics of common large bees and wasps which can be used to identify them.-External links:* * *...
- German waspGerman waspThe German wasp, or European wasp, Vespula germanica, is a wasp found in much of the Northern Hemisphere, native to Europe, northern Africa, and temperate Asia. It has been introduced and is well-established in many other places, including North America, South America , Australia and New Zealand...
- Hymenoepimecis argyraphagaHymenoepimecis argyraphagaHymenoepimecis argyraphaga is a Costa Rican parasitoid wasp whose host is the spider Plesiometa argyra. The wasp is unique in modifying the spider's web building behavior to make a web made of very strong lines designed to support the wasp's cocoon without breaking in the rain.-Reproduction:The...
- Median waspMedian waspThe median wasp, Dolichovespula media, is a wasp of the genus Dolichovespula native to Europe. Aside from its black-and-yellow coloration, it is very similar to Dolichovespula maculata, the bald-faced hornet, which is found in the USA, Alaska and Canada.The highly active workers need mainly only...
- Mud dauberMud dauberMud dauber is a name commonly applied to a number of wasps from either the family Sphecidae or Crabronidae that build their nests from mud...
- Paper waspPaper waspPaper wasps are -long wasps that gather fibers from dead wood and plant stems, which they mix with saliva, and use to construct water-resistant nests made of gray or brown papery material...
- Pepsis wasp / tarantula hawkTarantula hawkA tarantula hawk is a spider wasp which hunts tarantulas as food for its larvae. Tarantula hawks belong to any of the many species in the genera Pepsis and Hemipepsis in the family Pompilidae ....
- Pollen waspPollen waspPollen wasps are unusual wasps that are typically treated as a subfamily of Vespidae, but have in the past sometimes been recognized as a separate family, "Masaridae", which also included the subfamily Euparagiinae. It is a small subfamily, unique among wasps in feeding their larvae exclusively...
- Potter waspPotter waspPotter wasps are a cosmopolitan wasp group presently treated as a subfamily of Vespidae, but sometimes recognized in the past as a separate family, Eumenidae.-Recognition:...
- VespidVespidThe 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,...
- YellowjacketYellowjacketYellowjacket is the common name in North America for predatory wasps of the genera Vespula and Dolichovespula. Members of these genera are known simply as "wasps" in other English-speaking countries...
External links
- European hornet protection site (also available in French, German, Russian, Spanish and Swedish)
- Paper Wasps and Hornets
- Hornetboy's homepage
- Controlling Wasps, Hornets, and Yellowjackets
- Hornets & Yellowjackets
- Yellowjackets and Other Social Wasps
- Vespidae of the World
- yellowjackets and hornets of Florida on the UFUniversity of FloridaThe University of Florida is an American public land-grant, sea-grant, and space-grant research university located on a campus in Gainesville, Florida. The university traces its historical origins to 1853, and has operated continuously on its present Gainesville campus since September 1906...
/ IFASInstitute of Food and Agricultural SciencesThe University of Florida’s Institute of Food and Agricultural Sciences is a federal-state-county partnership dedicated to developing knowledge in agriculture, human and natural resources, and the life sciences, and enhancing and sustaining the quality of human life by making that information...
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