Paul Hetherington, director of communications and engagement at the Buglife charity, made the remarks after the earliest UK sighting of one of the hornets was confirmed on 11 March.

The sighting has led conservationists to warn that Asian hornets may have become established in the UK.

The flying insects measure at around 25mm in length while queens are approximately 30mm long. Their abdomens are mostly black and they are distinguished from European hornets by the fact they have yellow ends to their legs.

They prey on a wide range of insects including honeybees and bumblebees.

They were first spotted in the UK in 2016, with Mr Hetherington saying this year's earliest-ever sighting is "extremely worrying".

Speaking to Sky News' The UK Tonight with Sarah-Jane Mee, he said: "An adult Asian hornet can eat roughly 50 honeybees a day - that transpires to an entire nest of bumblebees for one hornet.

"So imagine what a nest of Asian hornets could be doing to our population of bees... They could have a catastrophic impact on bees because they've come in from abroad, there are not a lot of things that are going to predate them in this country.

"So it's very, very worrying."

Mr Hetherington added that it is "virtually certain" Asian hornets are "breeding and living in the UK" - with 14 of their nests destroyed in the UK across August, September and October last year.

He added that the hornets appear to be establishing in southern England where some of the UK's rarest bumblebees exist - such as the Shrill carder bee and the brown-banded carder bee.

"It'd be quite easy for them to have a devastating impact on populations like that," Mr Hetherington said.

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The bug expert added that the presence of Asian hornets could be "absolutely catastrophic" for consumers if too many bees, which pollinate a wide range of crops, are eaten.

Mr Hetherington continued: "If we lost all our pollinators, it would put about £2bn a year on our food bill for selective foods like fruit and peas, because we'd have to pay people the minimum to go out and hand-pollinate.

"The knock-on effect for consumers in this country alone would be absolutely catastrophic if they get established and wreak havoc."

Mr Hetherington said that it is already clear that Asian honeybees have established themselves in northern France and keeping them out of the UK is going to be very difficult.

Asian hornets, native to Asia, were reportedly spotted in Europe for the first time in southwest France in 2004.

They are thought to have come over in a consignment of pottery from China.

They are now reported to be established in Spain, Belgium, the Netherlands, Portugal, Italy, Switzerland, Germany and Jersey.