Asian hornets: AI to stop pest invading Britain and beheading our bees

In my previous article on Asian hornets (‘Asian Hornets: Bad for bees but good for tree work’, essentialARB February 2024) I said the 2023 tally for nests stood at 53 up until the end of October 2023. This figure was subsequently exceeded, with 72 nests recorded at 56 locations across 10 counties for the whole of 2023. All were in England, with the majority in Kent, but others were found in London, Essex, Surrey and Hampshire and some as far afield as Devon and Dorset, East Yorkshire and North Yorkshire.

This tally compares with just 13 nests found between 2016 and 2022. And the problem has clearly not gone away, because the first nest identification for 2024 was made near Canterbury in Kent in March.

Asian hornets and their nests are now being identified and destroyed during most of the year. The risk of establishment is higher in the southeast of England, with insects entering the country from continental Europe on cross-channel ferries and the motor vehicles they transport. The warmer, milder climate in southern England is thought to favour establishment, but as the 2023 distribution shows, the north of England and perhaps even Scotland are not immune from this pest, which is lethal to bees and capable of delivering a nasty sting. 

A typical Asian hornet nest discovered in a tree. (Image: Stock)

Many conservationists and apiarists at the sharp end say Asian hornet is already established in the UK, although DEFRA has not confirmed this. Whoever is right, Asian hornet appears to already be an England-wide problem. The ability to prevent establishment or eradicate an established population will depend on rapid and accurate location of infestations and their effective and safe destruction.

This is where AI comes into the picture, after scientists at the University of Exeter developed a prototype AI system called VespAI, which can spot Asian hornets with a high degree of accuracy and subsequently raise the alarm. 

A mixture of sugar and fermented fruit extracts soaked into a sponge cloth attracts insects including Asian hornets to the monitoring station. VespAI uses a compact processor (essentially a small computer) to operate and which stays dormant unless its sensors identify an insect within the size range of a hornet. If this happens, the system’s AI algorithm activates, analysing the image to determine if it is an Asian hornet. If an Asian hornet is detected, the monitor sends an alert to the user. Tracking teams can find the nest by watching which way the Asian hornets fly off. Repeating this from other nearby spots allows the likely location of the nest to be estimated by triangulation.

Preliminary trials were conducted on the island of Jersey in the Channel Isles which has a very high number of Asian hornet incursions. Thousands of images of Asian hornets and other insects were collected with the AI system learning to identify Asian hornets based on colouration, size and shape. The system proved to be more than 99 per cent accurate in identifying Asian hornets. 

In summer 2024 the research team will begin deploying updated prototypes in collaboration with the UK government, the National Bee Unit, the British Beekeepers Association and the company Vita Bee Health. They will be deployed in southeast England, where most Asian hornets are currently holed up in the county of Kent, but also in southwest England where sightings were made in 2023 in Dorset and Devon. Plans are for VespAI to become commercially available as soon as possible and primarily to local authorities and beekeepers who are at the forefront of this alien insect pest invasion.

Current UK response strategy depends on the public sighting, identifying and reporting Asian hornets to the relevant authorities, but most turn out to be cases of mistaken identity. Fewer than one per cent of suspected Asian hornet sightings eventually turn out to be correct.

Dr Peter Kennedy at University of Exeter, who worked on the project, said: “The majority of reports submitted are misidentified native species, meaning the agencies have to manually validate thousands of images every year.

“In some parts of Europe, detection relies on hornet trapping – but such traps kill a lot of native insects, and do little to impact Asian hornet numbers. VespAI ensures that live hornets can be tracked back to the nest, which is the only effective way to destroy them.”

The Asian hornet up close. Time to get familiar? (Image: Stock image)

Also on the research team is Thomas O’Shea-Wheller, who says the UK sits at the western edge of the European invasion front, and with ongoing yearly incursions there is an urgent need for improved monitoring systems. At the moment, local authorities have to rely on public sightings which, with the best intentions, are often inaccurate. He said: “Our goal was to develop something cost-effective and versatile, so anyone – from government to individual beekeepers – could use it.”

Asian hornets eat huge numbers of honey bees, with each hornet able to consume 50 bees a day, meaning a swarm can easily demolish a beehive of 30,000 bees.

They can also deliver a nasty sting. They originate in Asia, were first reported in continental Europe in 2004 and in the UK 12 years later in 2016.

Anyone, including DEFRA, who thinks Asian hornet could not establish (if it has not done so already) and become a big problem here, only need look to the Channel Islands. Jersey recorded 335 nests in 2023. The island is only 22 km from the coast of France, but by the same token the nests will be much easier to locate in such a small area. If Asian hornet becomes well and truly established in the hugely bigger land area of England it could turn out to be a nightmare, irrespective of artificial intelligence. Ten people in Jersey required urgent medical attention after being stung by an Asian hornet in summer 2023.

However, every cloud has a silver lining and Asian hornet could provide a lot of work for arborists, because someone will have to climb the trees to remove and destroy the nests, in much the same way that oak processionary moth has kept the arb sector busy.