Understanding the Yellow-Legged Hornet
By Jacques J. M. van Alphen, Naturalis Biodiversity Center
The yellow-legged hornet (Vespa velutina), also commonly known as the Asian hornet, has become an important concern for beekeepers and conservationists across Europe. Its rapid expansion, predatory behaviour and potential impact on pollinating insects have raised significant questions about how best to protect native biodiversity.
In a detailed paper entitled Facts about the Yellow-Legged Hornet, Jacques J. M. van Alphen examines the biology, spread and ecological consequences of this invasive species.
From a Single Arrival to Widespread Establishment
The yellow-legged hornet is believed to have arrived in France in 2004, possibly concealed within a shipment of Chinese pottery entering Bordeaux.
Since its introduction, the species has spread rapidly through Western Europe. Research suggests that its expansion has been aided by its ability to disperse over considerable distances, produce large numbers of reproductive queens and establish colonies in suitable habitats.
A Threat to Pollinators
One of the principal concerns surrounding the yellow-legged hornet is its impact on other insects, particularly honey bees and social wasps.
The paper highlights research indicating that pollinating insects make up a substantial proportion of its prey. Hornets can also interfere with normal foraging behaviour by hunting near hive entrances, discouraging honey bees from leaving their colonies.
These effects raise wider concerns about pollination, biodiversity and the health of ecosystems.
Can European Honey Bees Adapt?
The paper also examines how honey bees defend themselves against hornet attacks.
Some Asian honey bee species have evolved sophisticated defensive responses, including collectively surrounding attacking hornets. European honey bees generally have less effective defences, although research has identified differences in defensive behaviour between populations.
This variation may offer opportunities for natural selection to improve resistance over time, particularly among free-living honey bee populations.
Managing the Threat
Controlling the yellow-legged hornet presents considerable challenges. Its high reproductive capacity and ability to establish nests in difficult-to-access locations make population management complex.
The paper discusses nest removal, selective trapping and potential biological control methods, while recognising the limitations of existing approaches.
For those involved in native honey bee conservation, understanding these challenges is particularly important.
Read the full paper: Facts about the Yellow-Legged Hornet by Jacques J. M. van Alphen.
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