Asian Giant Hornet

The Asian giant hornet has reached fame thanks to its nickname online, the “murder hornet.” While the species’ stings can be quite painful, it’s estimated that hornets kill less than 40 people a year in countries across Asia.

For perspective, 89 people in the U.S. died in 2017 from native hornets, wasps, and bees, per the CDC.

The hornets are native to the Asian seaboard, stretching from Russia’s Far East to the tropics. However, in 2019 and 2020 sightings of these “murder hornets” began appearing in the Pacific Northwest, raising fears they could decimate local bee populations due to their signature decapitation of large honey bee populations with their large mandibles. The hornets then carry the thorax from their victims to feed their young.

Because a single murder hornet can kill up to 40 honey bees a minute, it only takes a few hornets to completely decimate an entire colony of honey bees in short order.

On October 23, 2020, the first U.S. “murder hornet” nest was found near Blaine, Washington, further raising fears the species could become invasive and threaten bee populations that are integral to pollinating many crops.

Incredible Asian Giant Hornet Facts!

• Murder hornets: The Asian giant hornet has attracted significant attention online thanks to its nickname of the “murder hornet.” Why the dramatic nickname? For one, the species can grow quite large, with queens reaching more than 2 inches in length.

• Voracious Predators: In addition to their large size, giant hornets received their “murder hornet” nickname from their voracious predatory habits. A single Asian giant hornet can kill more than 40 bees per minute by rapidly using its large mandibles to decapitate beer after bee!

• But Asian bees have evolved to face this threat! With Asian bees continually facing off against “murder hornets,” they’ve evolved a unique adaptation to fight hornets invading their nest. Bees swarm around the hornets and vibrate their flight muscles, raising their temperature to 117 degrees. Bees can withstand a temperature of 118 degrees, while hornets can only support internal temperatures of 115 degrees. They use this very slight difference to effectively “cook” murder hornets alive!

Classification and Evolution

The Asian giant hornet is the largest hornet species in the world with some queens reaching more than 2 inches in length. They can be found throughout Eastern Asia, particularly in Japan where they are commonly known as the Giant Sparrow Bee. It is not to be confused with the more placid Asian hornet which arrived in France in 2005 and, although similar in appearance to the Asian giant hornet, the Asian Hornet is thought to be no more dangerous than the European hornet. The Asian giant hornet was first classified in 1852 by a British entomologist called Frederick Smith, who worked in the zoology department of the British Museum. He later became the president of the Entomological Society of London from 1862 – 1863.

The earliest wasps have been around for as long as 240 million years, during the mid-Triassic era. Entomologist Andrey Martynov suggested that they came from snakefly-like ancestors. According to more recently discovered fossils, that are 260-270 million years old, this belief may be supported.

Different Types of Wasps

The Asian giant hornet belongs to the family Hymenoptera, of which there are more than 30,000 different species of insects. The hornet species, in the genus Vespa, contains 22 different species. Some of those are:

• Asian Hornet (Vespa velutina) – also known as the Asian predatory wasp
• Black-bellied Hornet (Vespa basalis)
• Greater Banded Hornet (Vespa tropica)
• Lesser Banded Hornet (Vespa affinis)
• Oriental Hornet (Vespa orientalis)
• Yellow Hornet (Vespa simillima)
• European Hornet ((Vespa crabro) – also referred to as the Old World hornet

Anatomy and Appearance

As the largest of the wasp species, the average Asian giant hornet grows to between 1.06 inches and 1.77 inches in length, with a wingspan of around 2.75 inches. A queen can grow to 2.16 inches but is similar in appearance to the worker hornets with an orange head, black mandibles, and a black and golden body. The Asian giant hornet has two sets of eyes, one compound and one ocelli, both of which are brown in color along with their legs. Unlike other species of wasps, as well as bees, the stinger of the Asian giant hornet is not barbed and therefore remains attached to its body once used. Therefore, Asian Giant Hornets are able to sting their victims over and over again, injecting a complex venom that is known to contain eight different chemicals.

“Murder Hornet” Nickname

The Asian giant hornet has received widespread media attention since it was first spotted in the United States in 2019. Most of this coverage refers to the hornets as “murder hornets.”

The first use of this name came from Japan in 2008. Its use exploded after a New York Times profile on the hornets on May 2020 adopted the “murder hornet” moniker.

While Asian giant hornets have stingers that can be quite painful to humans, they kill very few people across Asia every year. Instead, the greatest threat of this invasive species is to bee populations across the United States.

Distribution and Habitat

The Asian giant hornet is found throughout Eastern Asia in Korea, Taiwan, China, Indochina, Nepal, India, and Sri Lanka, but they are most commonly found in the mountains of Japan. They are found inhabiting higher altitude forests in both temperate and tropical areas, where there is plenty of food and suitable places to build a nest. The nest is founded by a fertilized female (known as the queen) who selects a suitably sheltered site such as the hollow trunk of a tree, where she begins to build herself a nest out of chewed-up bark. Wasp nests contain a series of single cells that together create the well-known honeycomb effect.

Behavior and Lifestyle

Asian giant hornets are known for their fearless and extremely aggressive attitudes, and they seem to favor one animal in particular, the honey bee. Asian giant hornets like to feed the honey bee larvae to their own young and are known to completely destroy whole bee hives in the process. Rather than using their stinger, Asian giant hornets, kill the guarding bees using their strong mandibles with extreme force and agility. One hornet is said to be able to tear up to 40 honey bees in half every minute just to get at what it wants (which once again, leads to its “murder hornet” nickname). Asian giant hornets are sociable insects, working together within the colony to forage for food, growing the size of the nest, and caring for the young. They are known as workers but they do not reproduce, as that is the job of the queen.

Reproduction and Life Cycles

Once having built her nest in the spring, the fertilized queen lays a single egg in each cell which hatches within a week. Asian giant hornet larvae undergo a five-stage changing process known as metamorphosis, in order to get to their adult form. This takes around 14 days by which point the hive has its first generation of workers that ensure that the colony as a whole is well-maintained. By the late summer, the population of the colony is at its peak with around 700 workers, most of which are female. The queen then begins to produce fertilized (female) and non-fertilized (male) eggs. The males leave the hive once they have reached their adult form and usually die once mated. The workers and current queens tend to die out in the autumn leaving the young fertilized queens to survive the winter and begin the process again the next spring.

Diet and Prey

The Asian giant hornet is a dominant predator within its environment, mainly hunting other insects, particularly bees. Asian giant hornets are also commonly known to kill larger Insects such as praying mantises and even other wasps and hornets. Adult Asian giant hornets are unable to digest solid proteins and instead only eat the fluids from their victims. They are also known to feed their catch to their larvae (particularly the honey bee larvae) in the form of a regurgitated paste. The larvae then secrete a clear liquid which the adults consume and are thought to give them a bit of an energy boost. Asian giant hornets predominantly use their mandibles rather than their powerful stingers in order to secure their prey.

Predators and Threats

Due to the fact that the Asian giant hornet is an apex predator within its environment, it has no real natural predators within its native habitats. Humans pose the biggest threat to the world’s largest wasp, mainly as they are consumed as part of normal diets in the areas where they are found. This is particularly common in the mountains of Japan where the Asian giant hornet populations are in the highest abundance. Despite its size and bad temper, numbers of the Asian giant hornet are declining in certain areas. This is mainly due to habitat loss in the form of deforestation. Honey bees in Eastern Asia are also starting to develop their own defense again the hornets, trapping them in their nest until it becomes too hot for this giant wasp and it dies.

Interesting Facts and Features

The stinger of the Asian giant hornet is 1/4 inch long and because it has no barb, the Asian giant hornet is able to sting its victims multiple times. The venom injected by the stinger is incredibly potent and contains eight different chemicals, each with a specific purpose. These range from tissue degeneration and breathing difficulties, to making the sting more painful and even attracting other hornets to the victim.

Experts have compared the pain of the sting as similar to that inflicted by a red-hot needle. This winged arthropod’s sting has a ranking of 2 on the Schmidt Pain Index. Phospholipase and mastoparan cause extensive inflammation by breaking down the cells in the skin, while histamine and acetylcholine aided by kinins are responsible for that awful pain.

Getting rid of all those toxins can prove taxing for the kidneys and can possibly lead to kidney damage.

The Asian giant hornet is a relentless hunter and only a few are said to be able to completely wipe out a 30,000+ Honeybee colony in a couple of hours. The saliva produced by the larvae of the Asian giant hornet is said to give them their renowned energy and stamina when consumed on a regular basis. When chasing their prey, they have been reported to travel distances of up to 60 miles, at a top speed of 25 mph.

Relationship With Humans

Oddly enough, these incredibly large and indeed dangerous insects, are actually eaten by people who share the habitat of the Asian giant hornet. The Asian giant hornet is consumed by some as a regular source of food and is most commonly deep-fried or served as hornet sashimi. Despite the fact that the venom of the Asian giant hornet is incredibly potent, it is only in rare cases when the person is more vulnerable, that it is actually the poison that has caused them to die. In Japan alone, an estimated 40 people are killed annually by stings from Asian giant hornets but fatalities are mainly caused by allergic reactions, often from multiple stings.

Conservation Status and Life Today

The Asian giant hornet is today listed as a species that is Threatened with extinction in the near future, should the circumstances surrounding its survival not change. Despite their dominance in their natural environments, the Asian giant hornet populations are being severely affected by habitat loss in certain areas, predominantly in the form of deforestation.