A giant murderous hornet has appeared in the United States, causing alarm amongst authorities.

The Vespa mandarinia, otherwise known as the Asian giant hornet, was sighted in Washington state, in the west coast of the U.S with state agriculture officials warning that they pose a threat to humans and the beekeeping industry, according to The New York Times.

'Murder hornet'

Growing up to five centimetres long, the hornets have the ability to wipe out a honeybee hive in a matter of hours, using their sharp mandibles to decapitate the bees.

When faced with a larger target like humans, the hornets utilise a long stinger which can penetrate a beekeeping suit.

A combination of the sting and the hornet's venom has been described by some as having hot metal pierce the skin.

The New York Times reported that multiple stings have been known to kill humans, with Japan recording up to 50 deaths a year from the insect nicknamed the 'Murder Hornet'.

Speaking to Reuters, Managing Entomologist at Washington state's agriculture department Sven-Erik Spichiger said that hornets — native to Southeast Asia, China, and Taiwan — were first seen in the U.S. in December 2019.

"The venom itself is fairly toxic and creates localised necrosis around the wound so you'll see melting flesh around the wound," he is quoted as saying.

YouTube channel Brave Wildnerness featured one of its hosts allowing himself to get stung by the hornet.

Coyote Peterson told the cameras right after he got stung that he felt dizzy, and that the pain was "searing".

"When the stinger went into my arm, I had this, like, wave. A wave came over me and I got super dizzy."

Recounting the sting afterwards, Peterson said that he felt pain for six hours after the fact.

Threatening agriculture

Spichier added that the appearance of the hornet in the U.S. posed a threat to agriculture and the beekeeping industry.

The Washington State Department of Agriculture described the hornets as leaving behind "piles of dead bees, most of them headless" before taking over the hive and using its brood to feed young Asian giant hornets.

The decimation of bee populations in the U.S. carries consequences for the pollination of agricultural systems, with Spichier telling Reuters that the spread of the hornets could be "pretty catastrophic".

While scientists are unsure about how the insect arrived on U.S. soil, one possible theory is that it was carried in a container ship that docked in a Washington port.

According to Reuters, the intentional transportation of the Asian giant hornet into the U.S. would be a violation of federal law.

The New York Times reported that scientists are now hunting down the hornets in an attempt to stop the insect from establishing a deep presence in the U.S.

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Top image screenshot from Brave Wilderness YouTube channel