Japanese giant hornet
Encyclopedia
The Japanese giant hornet (Vespa mandarinia japonica), is a subspecies of the Asian giant hornet
(V. mandarinia). It is a large insect and adults can be more than 4 centimetres (1.6 in) long, with a wingspan greater than 6 centimetres (2.4 in). It has a large yellow head with large eyes, and a dark brown thorax with an abdomen banded in brown and yellow. The Japanese giant hornet has three small, simple eyes on the top of the head between the two large compound eyes. As the name implies it is endemic to the Japanese islands
, where it prefers rural areas where it can find trees to nest in.
In Japan it is known as the .
ese mountain villages, the hornet is considered a delicacy when fried.
s often prefer European honey bee
s because they are more productive than the endemic Japanese honey bee
s. However, it is quite difficult to maintain a captive hive of European honey bee
s, as the hornets will often prey on the bees.
Once a Japanese giant hornet has located a hive of European honey bees it leaves pheromone markers around it, that within a short time attract nest mates that quickly converge on the hive. A single hornet can kill forty European honey bees in a minute and a group of 30 hornets can finish off an entire hive containing 30,000 bees in a little more than three hours. The hornets not only kill the bees, but also dismember them, leaving heads and limbs behind, to finally return to their nest with the bee thoraxes which they feed to their larvae. The hornets also gorge themselves on the bees' honey.
The Japanese honey bee, on the other hand, has a defense against attacks of this manner. When a hornet approaches the hive to release pheromones, the bee workers emerge from their hive in an angry cloud-formation with some 500 individuals. As they form a tight ball around the hornet, the ball increases in heat to 47 °C (116.6 °F) from their vibrating wings, forming a convection oven as the heat released by the bees' bodies is spread over the hornets. Because bees can survive higher temperatures (48 to 50 °C (118.4 to 122 F)) than the hornet (44 to 46 °C (111.2 to 114.8 F)), the latter dies.
which is injected from the 6.25 millimetre (0.246062992125984 in) stinger and attacks the nervous system
and damages tissues of its victims.
Compared to other hornet venom, it is not particularly lethal by weight (having an of 4.1 mg/kg, which compares to the deadliest wasp venom by weight of Vespa luctuosa
at 1.6 mg/kg). Instead, the potency of its sting derives from the relatively large amount of venom it is able to inject with each sting. Being stung is extremely painful and requires hospital treatment. On average 40 people die every year of anaphylactic shock
after having been stung, which makes the Japanese giant hornet the most lethal animal in Japan, as bears kill about ten people and venomous snakes kill five to ten people each year.
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...
(V. mandarinia). It is a large insect and adults can be more than 4 centimetres (1.6 in) long, with a wingspan greater than 6 centimetres (2.4 in). It has a large yellow head with large eyes, and a dark brown thorax with an abdomen banded in brown and yellow. The Japanese giant hornet has three small, simple eyes on the top of the head between the two large compound eyes. As the name implies it is endemic to the Japanese islands
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
, where it prefers rural areas where it can find trees to nest in.
In Japan it is known as the .
Description
Workers forage to feed their siblings. Their diet consists of a wide range of insects, including crop pests, and for this reason the hornets are regarded as beneficial. The workers dismember the bodies of their victims in order to return only the most nutrient-rich body parts, such as flight muscles, to the nest. There, the workers chew the prey into a paste before feeding the larvae who in return produce a fluid consumed by the workers. This fluid, known as vespa amino acid mixture (VAAM), is the only sustenance workers imbibe during their adult lives, which is remarkable considering they can fly 100 kilometres (62.1 mi) per day and reach up to 40 kilometres per hour (24.9 mph). The fluid thus enables intensive muscle activities over extended periods and is being produced artificially to increase athletic performance. In many JapanJapan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
ese mountain villages, the hornet is considered a delicacy when fried.
Bee predation
In Japan, beekeeperBeekeeper
A beekeeper is a person who keeps honey bees for the purposes of securing commodities such as honey, beeswax, pollen, royal jelly; pollinating fruits and vegetables; raising queens and bees for sale to other farmers; and/or for purposes satisfying natural scientific curiosity...
s often prefer European honey bee
European honey bee
The Western honey bee or European honey bee is a species of honey bee. The genus Apis is Latin for "bee", and mellifera comes from Latin melli- "honey" and ferre "to bear"—hence the scientific name means "honey-bearing bee"...
s because they are more productive than the endemic Japanese honey bee
Apis cerana japonica
Apis cerana japonica is a subspecies of honeybee native to Japan. It is commonly known as the . This subspecies was determined, through an analysis of mitochondrial DNA, to have originally come from the Korean peninsula. They have been observed moving into urban areas due to lack of natural...
s. However, it is quite difficult to maintain a captive hive of European honey bee
European honey bee
The Western honey bee or European honey bee is a species of honey bee. The genus Apis is Latin for "bee", and mellifera comes from Latin melli- "honey" and ferre "to bear"—hence the scientific name means "honey-bearing bee"...
s, as the hornets will often prey on the bees.
Once a Japanese giant hornet has located a hive of European honey bees it leaves pheromone markers around it, that within a short time attract nest mates that quickly converge on the hive. A single hornet can kill forty European honey bees in a minute and a group of 30 hornets can finish off an entire hive containing 30,000 bees in a little more than three hours. The hornets not only kill the bees, but also dismember them, leaving heads and limbs behind, to finally return to their nest with the bee thoraxes which they feed to their larvae. The hornets also gorge themselves on the bees' honey.
The Japanese honey bee, on the other hand, has a defense against attacks of this manner. When a hornet approaches the hive to release pheromones, the bee workers emerge from their hive in an angry cloud-formation with some 500 individuals. As they form a tight ball around the hornet, the ball increases in heat to 47 °C (116.6 °F) from their vibrating wings, forming a convection oven as the heat released by the bees' bodies is spread over the hornets. Because bees can survive higher temperatures (48 to 50 °C (118.4 to 122 F)) than the hornet (44 to 46 °C (111.2 to 114.8 F)), the latter dies.
Venom
The Japanese giant hornet is large and fearsome, but it is not particularly aggressive unless it feels threatened. It has a venomVenom
Venom is the general term referring to any variety of toxins used by certain types of animals that inject it into their victims by the means of a bite or a sting...
which is injected from the 6.25 millimetre (0.246062992125984 in) stinger and attacks the nervous system
Nervous system
The nervous system is an organ system containing a network of specialized cells called neurons that coordinate the actions of an animal and transmit signals between different parts of its body. In most animals the nervous system consists of two parts, central and peripheral. The central nervous...
and damages tissues of its victims.
Compared to other hornet venom, it is not particularly lethal by weight (having an of 4.1 mg/kg, which compares to the deadliest wasp venom by weight of Vespa luctuosa
Vespa luctuosa
Vespa 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...
at 1.6 mg/kg). Instead, the potency of its sting derives from the relatively large amount of venom it is able to inject with each sting. Being stung is extremely painful and requires hospital treatment. On average 40 people die every year of 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...
after having been stung, which makes the Japanese giant hornet the most lethal animal in Japan, as bears kill about ten people and venomous snakes kill five to ten people each year.