Experts warn Jersey stronghold of invasive Asian hornets could accelerate spread to UK

The invasive Asian hornet (Vespa velutina) has established a large and rapidly growing presence on Jersey, prompting scientists, beekeepers and conservation groups to warn the island could act as a staging ground for wider colonisation of the United Kingdom.

Since the start of the year officials and volunteers have recorded nearly 500 nests on Jersey, with one local expert saying 469 nests have been logged so far — roughly four times the number recorded the previous year. Each nest can contain thousands of insects, and experts estimate the island could be harbouring millions of hornets at present. Authorities say a backlog of nests is awaiting treatment as limited numbers of dedicated invasive species officers, pest controllers and volunteers struggle to respond to an unprecedented volume of reports.

The Asian hornet, also known as the yellow-legged hornet, is native to southeast Asia but has spread across much of continental Europe since first arriving in France in the early 2000s. The species was first confirmed in the UK in 2016 and has been recorded more frequently in southern England in recent years. Researchers and campaigners warn that Jersey’s burgeoning population increases the risk of more hornets reaching Britain either by accidental importation on goods such as potted plants cut flowers timber soil or fruit or by natural dispersal, with individual hornets known to cross the short Channel on warm days.

John De Carteret, a founding member of the Jersey Asian Hornet Group, said the scale of reports has put “tremendous pressure” on the island’s reporting system. "Combined efforts of the two government invasive species officers along with professional pest controllers and volunteers are trying to keep up with the sheer logistics of nest treatments," he said, adding that not all public reports are receiving prompt follow-up because staff are stretched.

Scientists and conservation bodies have emphasised why the spread is a concern. Asian hornets are effective predators of insects including honey bees and other pollinators. A University of Exeter analysis this year identified about 1,400 different species in the guts of Asian hornets, with honey bees among the most frequent prey items. The hornets often hunt at the entrances to bee hives capturing foraging bees on the wing and returning the dismembered prey to feed larvae.

The potential impact on pollinator populations has broader implications for ecosystems and agriculture. A multinational assessment by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services has warned declining pollinator numbers could pose risks to food production. Britain’s bees are estimated to have declined substantially in recent decades, and conservation groups say the arrival of a new, voracious predator could exacerbate those losses.

Identification and reporting have become priorities. Asian hornets are smaller and more slender than the native European hornet and can be distinguished by bright yellow tips on their legs and an orange shaded head. Professor Helen Roy, an ecologist at UK Centre for Ecology & Hydrology and the University of Exeter, said leg colouration is among the most immediately identifiable features: "Yellow-legged hornets have yellow and brown on their legs whereas European hornets' legs are only brown." Nests are typically egg-shaped and constructed from chewed wood fibres and saliva, often measuring around half a metre.

Authorities urge members of the public not to approach or disturb suspected nests. The British Beekeepers' Association advises against attempting removals and warns that stings can be painful and dangerous to people with allergies. Plantlife and other charities stress that all potential sightings should be reported to the appropriate non-native species reporting systems so responses can be prioritised.

Reporting channels include the Asian Hornet Watch app and an online form maintained by the UK Centre for Ecology & Hydrology. UKCEH vets reports from the public, and experts say accurate sightings from citizen scientists have been valuable in building surveillance networks and refining alert systems. Nevertheless, those systems depend on capacity to follow up confirmed threats with nest destruction or containment measures.

Control measures typically involve locating and destroying nests before colony growth peaks. Queens begin building nests in spring and populations expand through summer, with nests sometimes reaching several thousand workers. Local teams have combined government resources private pest controllers and volunteers to treat nests but say more hands and funding are needed to keep pace with this year’s surge.

Jersey’s situation highlights the continual challenge posed by non-native species in an interconnected world. Invasive insects can arrive unintentionally on traded goods or spread naturally across short distances of open water, and when they find suitable conditions they can multiply rapidly. Officials and scientists say vigilance and timely reporting remain central to early detection and rapid response, while longer-term management will require sustained resources and coordinated action across jurisdictions to limit ecological and economic harm.