Biologists at the University of Exeter have conducted the first large-scale study of the diet of the Asian hornet (Vespa velutina), utilizing deep sequencing to characterize the larval gut contents of over 1,500 samples from Jersey, France, Spain, and the UK. Although the European honeybee was the most common species found in the hornets, their diet is a lot broader. The analyses detected 1,449 invertebrate species, with greater prey richness in samples from southern latitudes.
The Asian hornet (Vespa velutina). Image credit: Gilles San Martin / CC BY-SA 2.0.
An invasive species, Asian hornets are now found in much of western Europe.
Nests are destroyed in the UK mainland each year as authorities try to keep the species out.
“Asian hornets are known to prey on honey bees, but until now the full range of their diet hasn’t been tested,” said Dr. Siffreya Pedersen, a researcher at the University of Exeter.
“The diet varied strongly over the seasons and between regions, showing that they are highly flexible predators.”
“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.”
In the study, Dr. Pedersen and colleagues used a method called deep sequencing to identify prey species in the guts of more than 1,500 Asian hornet larvae, which eat food provided by adult hornets.
Of the top 50 invertebrate prey species identified, 43 are known to visit flowers — and among these were Europe’s three main crop pollinators: the European honeybee, the buff-tailed bumblebee and the red-tailed bumblebee.
“Insects play vital roles in enabling ecosystems to function — including pollination, decomposition and pest control,” Dr. Pedersen said.
“Our study provides important additional evidence of the threat posed by Asian hornets as they spread across Europe,” said Dr. Peter Kennedy, also from the University of Exeter.
The researchers identified 1,449 operational taxonomic units in the guts of hornet larvae.
More than half could be identified as specific species, but the rest could not — so the exact number of species found in the samples is not certain.
“We have provided the most comprehensive view of the diet of Asian hornets in Europe to date, highlighting an extremely broad and flexible range of potential prey,” the scientists said.
“We have shown that dietary composition varies between geographical regions and across the hornets’ activity season, indicating high adaptability to new ecosystems; driving both the invasive success of Asian hornets, and the risk that they pose to a broad spectrum of native invertebrate fauna.”
“The elevated dietary prevalence of European honeybees concurs with previous studies and reports from beekeepers, supporting concerns over the risk to apiculture.”
“Our results also reveal a further potential ecosystem-level pressure as we find that Asian hornets demonstrate a high predation frequency on wild pollinators and recyclers, implying a threat to pollinator and recycler diversity and resultant ecosystem services.”
The study was published in the journal Science of the Total Environment.
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Siffreya Pedersen et al. Broad ecological threats of an invasive hornet revealed through a deep sequencing approach. Science of the Total Environment, published online March 4, 2025; doi: 10.1016/j.scitotenv.2025.178978
