Asian Giant Hornert Fact File
Asian giant hornets are also known as "murder hornets" due to their behavior of entering bee hives and killing all the residents inside.
They primarily feed on other insects but queens will feed on sap after they finish their period of overwintering and larvae are feed regurgitated food by workers in the nest.
Asia is the native home of the Asian giant hornet where they are present on the mainland but are best known from Japan. Occasional populations have been recorded in North America from accidental releases believed to have originated in goods being shipped.
The Asian giant hornet hatches from an egg then spends time as a larvae. Eventually they enter a cocoon and will then emerge as an adult.
Learn more about these incredible invertebrates by reading on below.
The Asian giant hornet is colored orange and black in bands across its abdomen. Their head is colored orange while the thorax is dark brown.
Sitting between the thorax and abdomen is a small additional segment known as the wasp waist which is used to curl the abdomen under the thorax and head so they are able to sting.
On the back are wings with a span of up to 7.6cm (3in) across.
Asian giant hornets are regarded as the world's largest hornet species and measure in at 3.8cm (1.5in) long. Queens are significantly larger than workers.
Asian giant hornets are omnivores which feed on a range of other insects such as bees. Queens feed on sap after they emerge from their period of overwintering.
They are covered by hard armor which allows them to raid bees nests as it makes them resistant to bee stings.
Asia is the native home of the Asian giant hornet. Here they are found on the mainland along with on the island of Japan.
The species has been discovered in North America in recent years. Populations have been recorded in Canada and the United States. It is suspected that this population came from queens which stowed away in packages being shipped. The two populations discovered so far were not related to one another.
The Asian giant hornet live in nests which are burrowed in to the ground. It is most common for them to take over nests abandoned by other animals such as rats.
Most of their habitats are in mountainous areas. They are unable to tolerate areas with extremes of temperature.
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In fall the adult males and new queens will emerge. Males leave first and wait at the entrance of a nest for new queens which emerge roughly 1 month later. Mating must take place before winter when the males will pass.
Queens then overwinter in a sheltered space and emerge at the start of spring. She is fertilized and feeds on sap while seeking out a site where they can nest. This is often a pre-existing site such as a rodent burrow.
She will initially care for the first eggs and young herself. By the time there are 40 though they will begin to care for the duties outside of the nest and the queen will become a resident.
After leaving their egg the young Asian giant hornet is a larvae. They must go through five larval stages to reach adult size. Larvae are feed on a paste of regurgitated food by the workers.
After completing their larval stage they will enter a pupal phase during which they spend 18 days in a cocoon.
When many workers are present they begin to produce males and queens. Males develop from unfertilized eggs while females emerge from fertilized eggs.
They have a longer stinger than the average bee or wasp and their venom is considered more toxic. As such you should exercise caution if near an Asian giant hornet.
When they sting the stinger is not punctured as in bees.
Predators and Threats
Birds of prey such as the honey buzzard may prey on them.
Asian giant hornets affect honeybee populations as they feed on honeybees and their brood. Groups of 10 to 20 hornets enter a nest and can kill as many as 30,000 individual bees in an hour.
Asian honey bees can defend themselves through a unique strategy. They will surround a hornet in a tight pack and then bear their wings generating heat which will raise the hornet's body temperature and kill them.
In their native range the species is considered to be relatively abundant.
They may also be known as the "giant sparrow wasp." Their habit of killing bees has led to the name "murder hornet."
The Nature Box, CC BY 4.0 <https://creativecommons.org/licenses/by/4.0>, via Wikimedia Commons
Alpsdake, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons
Yasunori Koide, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons
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