An exotic new beastie – the Asian hornet – is spreading fast across Europe, and this is bad news for the continent’s honey bees.
You don’t win a prize by guessing where the Asian hornet (Vespa velutina) originates from. It’s resident in the tropical regions of south-east Asia, in countries like northern India, Pakistan, Afghanistan, China, Burma, Thailand, Vietnam and Malaysia.
Asian hornets in Europe
The species was first identified in Europe in France in 2004. It probably arrived in a shipment of pottery imported from China. By 2009, several thousand nests were located in the area of Bordeaux and surrounding departments. By the end of 2015 Asian hornets were reported over most of France. The species was reported in Spain in 2010, Portugal in 2011, Italy in 2012, and the UK in 2016.
Asian hornets in Belgium
The species was first reported in Belgium in 2016. Since then it has spread rapidly throughout the country. This is not surprising. From every nest, between 50 and 500 new queens can be bred, to leave and start a new nest. Thankfully, only 10% of these survive the winter, and only 10% of the survivors can successfully establish a nest. So from every nest, around five queens per nest are likely to disperse and can start building a new nest up to 60 kilometers away. The spread of the animal therefore occurs at lightning speed. Just check these three distribution maps:
Why is the Asian hornet a threat?
Asian hornets in Europe are significant predators of bees. In France, they have consumed large numbers of bees, including the well-known European honey bee and many lesser-known solitary and colonial bee species. Nature conservation organizations are therefore seriously concerned about the impacts of Asian hornets on bees, as these pollinating species are an essential component of well-functioning ecosystems.
The major concern about Asian hornets in Europe is that when they find a honey bee colony or a beehive, they tend to settle down in that area and specialize in honey bees as their prey. The Asian hornet hunts in groups on honeybees in front of the beehive. Honeybees have little defence against this new invader; they are not adapted to repel it.
How to identify an Asian hornet
The Asian hornet is smaller than the European hornet (Vespa crabro). Queens can reach up to 30 mm, and workers up to 25 mm in length. European hornet queens can reach 35 mm. Here’s a size comparison of four similar insects:
There are several key features to look out for which will help you distinguish between an Asian hornet and our native European hornet. The main distinguishing feature of an Asian hornet is its almost entirely dark abdomen – except for the 4th segment which is yellow. European hornets, on the other hand, have a brown and yellow striped abdomen.
In addition, whereas the legs of European hornets are dark, Asian hornets have bright yellow tips to their legs. This is why they also go by the name Yellow-legged hornet.
this is not the European hornet
European hornets are an integral part of our native wildlife, playing an important ecological role, and should be valued. They hunt many species of insects to feed their larvae. Many of these insects are considered to be garden pests. European hornets also prey on honey bees, but nowhere near the extent to which Asian hornets do. Despite their unmerited fearsome reputation, European hornets are not usually aggressive, and will only sting when they feel threatened.
Nor is it the Asian giant hornet
The Asian hornet (Vespa velutina) is also not to be confused with the Asian giant hornet (Vespa mandarinia), commonly known as the murder hornet. The Asian giant hornet is the world’s largest hornet and can reach a whopping 45 mm in length. It is also native to east and south Asia as well as the Russian Far East. It was discovered in the Pacific North-West of North America in late 2019. Since then nests have been found elsewhere, prompting concern that it could become an invasive species. This hornet too is a serious threat to honey bees.
To avoid “unintentionally bolstering anti-Asian sentiment” the Entomological Society of America and the Entomological Society of Canada recently adopted a new name for this insect, calling it the Northern giant hornet.
What can we do?
It’s vital that Asian hornets in Europe are reported and that their nests are destroyed to decelerate their spread and reduce their impact on honeybees.
Have you spotted an Asian hornet in Belgium or the Netherlands? Or do you think you have found a nest of Asian hornets?
- In Flanders you can report it via the Vespa-Watch website and provide details about your observation.
- If the Asian hornet is in Wallonia you can use this website and form.
- If in Brussels, notify observations.be and if you find a nest, contact the fire service.
- If you spot an Asian hornet in the Netherlands you can submit your sighting to Waarneming.nl.
This way, experts can determine whether it is really an Asian hornet and the destruction of its nest can be planned. Destruction is specialized work that requires training and proper safety protection so should only be carried out by an expert.
I too would be very interested to hear of your Asian hornet observations in Belgium, so please add them in the comments below. And if you have any photos I would love to include them here. You can send me photos via my contact page.
Also, please share this post among your friends so this information can be disseminated as widely as possible.
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Will keep look out our side of Channel … and refer to your excellent description .
Thanks Elaine. According to the government: “There has been one confirmed sighting of Asian hornet in the UK in 2022. There have been a total of 22 confirmed sightings of Asian hornet since 2016.”
I have my swatter at the ready!
Well done Frag.
Thanks for this valuable information, Denzil. Wonder when we will have our infestation on this side of the pond. We are dealing with spotted lanternfly at the moment.
Well over there you have the Asian Giant Hornet beginning to appear in greater numbers. It’s bigger than ours (of course!).
Encourage native plants to bolster native bee populations.
That is certainly one way to help bees, Christine.
Very informative, Denzil. I imagine that their populations will also increase as our planet warms up more.
I would imagine so too Rosaliene. I believe in Europe the warming climate is extending the range northwards of many insects.
It’s always a worry when invasive species start to take over. Hopefully these little pests will be easily controlled.
I think now is the critical period Carol. Once a species gets well-established it’s extremely difficult to eradicate it.
Thanks for the interesting post.
Any idea on how to report them in Brussels? I came across a nest of some sort of large exotic wasp/hornet in the Forêt de Soignes a couple of days ago – I’m not sure if they were Asian hornets (they looked a bit more colourful than in the pictures) but I’m pretty sure they weren’t your typical Belgian wasps/hornets.
I also saw a very large strange hornet/wasp here last summer, these kinds of things seem to be rapidly becoming quite widespread.
Thanks for your comment and appreciation RP. Brussels often falls in the gap between Flanders and Wallonia doesn’t it? Apparently you should contact the fire service, and specifically Bernard Demarteau
Indeed – thanks!
This is an important post to share. I just returned from six weeks in Washington State (USA) where scientists with the state department of agriculture are expected to place 1,000 traps this year in an attempt to control (and hopefully wipe out) this invasive species.
That’s quite a commitment, it will be interesting to see how it goes. Here the exterminators are working flat out, with new nests discovered every day.
Thank you for this post, Denzil. I have been looking up the information on these hornets as I am pretty sure it was an Asian hornet that flew into my serre last week. It shocked me because it was so big, but I think it’s colours were those of the Asian and not the European hornet. I live just over the border from Belgium in Zeeuws Vlaanderen. I’ve now reported my sighting to Waarneming.nl. I cannot be certain that it was an Asian hornet, but it seems likely from what I’ve now read. It seemed very lethargic, but that was probably because it was pretty cold.
Glad you reported it Valerie and found my post useful! Hope your serre is now a hornet-free zone!