Heatwaves fuel Asian hornet invasion

Asian hornet populations are expected to increase rapidly in size as Britain faces another of its hottest years on record.

Experts have warned that unusually warm temperatures could cause an explosion in activity among the invasive species’ queens.

The Met Office is predicting 2026 to be one of Britain’s hottest years on record, following an unusually warm spring.

Luke Newnes, an expert on Asian hornets, said: “With 2026 is tracking as one of the warmest years in recent records, the warmer conditions are likely to accelerate emergence activity.”

Asian hornets, which can eat around 11kg of insects in a season, pose a risk to British honeybees as they make up a third of their diets. The remainder is made up other pollinators such as moths, flies, butterflies and other types of bee.

Asian hornets were first sighted in the UK in 2016 but experts warned last year that they had successfully survived winter for the first time.

Since the first nest was destroyed a decade ago, the number of nests in Britain has risen to 161, up from 24 in 2024. One nest can produce dozens of queens, meaning that if one nest is missed, 30 more can crop up the following year.

Mr Newnes said: “The concern with Asian hornets is how quickly populations can scale once queens establish successfully.

“What makes 2026 particularly concerning is the acceleration we’re now seeing in both sightings and geographical spread.

“We’re no longer talking about isolated coastal incidents. Sightings are appearing much further inland, and many experts now believe the focus has shifted from eradication to long-term management.”

The insects were once confined to south-east Asia but warmer weather has allowed them to spread north to Europe.

In the UK, they are most commonly found in the south and south-east regions of England, often emerging from cars, lorries and fruit that have crossed the Channel.

They also appear to be inching their way north, with a nest seen in Runcorn, Cheshire, in September last year.

Niall Gallagher, the technical manager at the British Pest Control Association, warned that it was “crucial” to prevent the spread of the species, saying they would “disrupt our native ecosystems and impact crop production”.

Dr Peter Kennedy, a leading conservationist at the University of Exeter, added: “The only means of halting the spread, or limiting it, is to find and destroy nests as soon as possible.”

But experts have cautioned against people approaching or attempting to remove the nests without contacting professionals, because the hornets become aggressive when disturbed.

Instead, they are encouraging the public to download the Asian hornet app on their phones. This allows people to report sightings to the National Bee Unit, who will hunt the hornets if the sighting is validated.

Britain broke its record for the hottest May nights for three consecutive days last week.

The Met Office said records for the warmest minimum temperatures for the month were broken when Camborne, Cornwall, did not drop below 21.4C overnight.

Alex Burkill, a Met Office meteorologist, called the record-breaking heat “extraordinary” and “quite worrying”.