1,400 species eaten by Asian hornets, study finds
Asian hornets are known to prey on honey bees, but their full diet had not been researched.
A study into Asian hornets has discovered approximately 1,400 different species inside of their guts.
Amongst the prey consumed by hornets were a wide range of bees, wasps, flies, beetles, butterflies, moths and spiders.
Asian hornets are an invasive species which have been spreading across western Europe. They are considered to be one of many threats faced by insect populations in the continent.
To combat the threat of Asian hornets, authorities in the UK regularly destroy their nests.
While Asian hornets are well-known for preying on honey bees, their full diet had not been researched.
Researchers from the University of Exeter tested samples from France, Spain, Jersey and the UK during the hornet’s active season. They performed deep sequencing on the guts of over 1,500 Asian hornet larvae, which eat food provided by adult hornets.
The study found 1,449 ‘operational taxonomic units’ inside the larvae guts.
Although more than half could be identified as specific species, many could not. This means that the exact number of species found in the samples is uncertain.
However, this dietary variation could indicate that Asian hornets are a highly flexible predator.
Among the top 50 invertebrate species identified in the Asian hornet were 43 species which are known to visit flowers. This included the European honey bee, the buff-tailed bumblebee and the red-tailed honeybee – Europe’s top three main crop pollinators.
The honey bee was the most abundant across gut samples, and was found in all of the sampled nests.
Researchers say that the decline of these insects could have an impact on key ecological functions. This includes pollination, decomposition and pest control.
Siffreya Pederson, lead author of the study, 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.
“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.”
The full study can be found in the journal Science of the Total Environment.
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