Researchers have issued a warning about invasive Asian hornets, which are consuming hundreds of insect species, many of which are important pollinators.
The findings by University of Exeter researchers, derived from tests on the guts of more than 1,500 larvae, highlight concerns about the additional threat the hornet poses to native insects. These insects are already under pressure from farming, land use changes, and chemical pollution.
The study also draws attention to the potential impact on agriculture, noting that 43 of the 50 most commonly identified species in the hornet larvae’s diet are known to visit flowers. These include Europe’s three main crop pollinators – the honey bee, buff-tailed bumble bee and the red-tailed bumble bee.
The Asian hornet or yellow-legged hornet, a voracious invasive, is native to southeast Asia and arrived in France in a cargo of pottery from China about 20 years ago, spreading rapidly across the continent.
Its main prey is the honey bee – it can kill 50 a day – and it has devastated colonies in France and Italy.
It was first seen in the UK in 2016, and there have been regular sightings since, including 44 confirmed in 2024 – mostly in Kent and east Sussex – although a rapid response approach to destroy hornets and nests has limited its spread in Britain.
The researchers carried out genetic analysis in a method called “deep sequencing” to identify prey species in the guts of more than 1,500 hornet larvae from 103 nests in Jersey, France, Spain, and the UK.
They identified 1,449 different prey which had been fed by adult hornets to their larvae in the nests, more than half of which (55%) could be identified as a specific species.
Prey included a wide range of flies, wasps, bees, butterflies, moths and spiders, with honey bees, common wasps and blow flies most commonly found.
While the hornets have a preference for honey bees, which were found in all nests and almost all samples, a wide range of other species were also recorded, showing they are “opportunistic” and prey on any creatures that are abundant in the areas near their nests.
The study’s lead author Siffreya Pedersen said: “Asian hornets are known to prey on honey bees, but until now the full range of their diet hasn’t been tested.
“The diet varied strongly over the seasons and between regions, showing that they are highly flexible predators.”
She added: “Insects play vital roles in enabling ecosystems to function – including pollination, decomposition and pest control.
“Most insect populations are in decline due to factors such as habitat destruction and chemical pollution. The expanding area inhabited by Asian hornets poses an extra threat,” she warned.
