Asian hornets invading further into Britain than ever before

The non-native insects prey on honeybees, butterflies and beetles.

South West Water has urged residents to report any encounters with the species as concerns mount over its westward advance.

Channel Islands authorities have meanwhile recorded unprecedented numbers of queens and nests, describing the coming period as a critical test of containment efforts.

Queen hornets are being carried on winds from France towards Kent, with the established population creeping closer each year, according to the Devon Hornet Action Team.

Simon O'Sullivan from the group told the BBC: "In Somerset, just over the border from Tiverton, we have seen Asian hornets, so they're slowly coming towards us and we're trying to get organised."

By September 3, the National Bee Unit had logged 167 yellow-legged hornet sightings and 53 nests throughout Britain.

The non-native insects prey on honeybees, butterflies and beetles

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A single nest can consume approximately 11kg of native insects in one season, and Mr O'Sullivan warned that without intervention, "they'll spread very rapidly".

Weather conditions play a decisive role in determining how quickly the hornets become established in the region.

Mr O'Sullivan said: "These long, hot summers will certainly increase the population, but again, very long, wet winters will have an adverse effect on overwintering queens."

A prolonged warm summer followed by a dry winter could see numbers rise sharply, he added, predicting significantly more hornet reports across Devon and Cornwall within two to three years.

South West Water has urged residents to report any encounters with the species as concerns mount over its westward advance

SOUTH WEST WATER

Michael Grindley, Cornwall's Asian hornet coordinator, noted the insects are also skilled stowaways, hiding beneath vehicles in cargo and arriving at ports such as Falmouth, Newlyn and Fowey aboard yachts.

Mr Grindley warned that roughly half the hornets' diet consists of bees, with the rest made up of flies, wasps and butterflies, all vital pollinators of fruit crops.

"So we'll have lots of wheat and lots of corn, but no tomatoes, no fresh fruit, no soft fruit," he said, adding that bird and freshwater fish populations would also decline as insect numbers fall.

In the Channel Islands, where Asian hornets first appeared in Jersey in August 2016, 734 nests have been reported so far this year compared with around 500 at the same point last year.

Alastair Christie, senior scientific officer for invasive species at the States of Jersey Environment Department, called the current approach "unsustainable," describing it as a "challenging situation".

Guernsey has adopted a two-stage strategy to combat the threat.

Annelotte Baas-Jehan, the island's invasive non-native species policy and coordination officer, explained that the first phase involves spring queening, trapping queens before they can establish nests using a network of traps placed every 500 metres and checked daily.

The second phase, called Track Don't Trample, relies on the public reporting sightings and flight directions during summer and autumn.

South West Water's invasives and biosecurity officer Rebecca Northey called the Asian hornet a "major threat to our native insects".