How to recognise the Asian hornet in the UK.
What is an Asian Hornet?
As its name suggests, the Asian hornet is a species of hornet from Asia. Whilst our UK hornets have evolved as part of our ecosystem, the Asian hornet is an insect out of place.
There are no natural controls in Europe where it is an invasive, destructive alien. It is a highly effective predator of other insects. In 2004 it arrived in France and has now spread rapidly across most of Europe and the Channel Islands. It has devastated honeybee colonies and threatens native species of beneficial insects such as bumblebees. The fear is that Asian hornets will cause similar damage here if they spread as they have done in mainland Europe.
Are Asian Hornets coming to the UK?
Asian Hornets may be able to cross the channel from France or come over in imported pot plants, cut flowers or fruit, and on timber.
The British Beekeepers Association (BBKA) has set up monitoring groups amongst beekeepers and Gloucestershire beekeepers have seen and reported hornets in the past. Concerted action has stopped the hornets spreading for now.
So far this year there have been 28 nests found in the UK. This is a big increase on the last few years (perhaps because Covid travel restrictions kept numbers down in these years.)
You can see a map of recent Asian hornet sightings by following this live link. The map also shows sightings from previous years.
The Asian hornet is a non-native species that could destroy our pollinators if it becomes established in the UK.
When is the Asian hornet active?
These hornets are active between April and November BUT activity peaks in August/September when these hornets are building secondary nests. They have lots of young to feed, particularly new queens, so they are busy hunting.
Honeybees are an easy target. Unlike Asian honeybees, which have had Asian Hornets in their world for millions of years, our European honeybees have no natural defences. There are thousands of honeybees in one hive - they are a bee buffet for the hornet.
The hornets will hang around a hive (this is called hawking) waiting for the bees to come out. A hornet can kill up to 50 bees a day. Their presence stops the bees leaving to forage and so, ultimately, the hive weakens. It might not fail immediately but is unlikely to be strong enough to go into winter.
The BBKA's Asian Hornet Awareness Week 2023 (4 -10 September 2023) aims to publicise how we can all help spot and report sightings of this damaging insect. We talk about this insect on our bee keeping courses because it's of concern to beekeepers BUT because of the potential impact on general pollinator biodiversity, this is an insect we should all look out for.
What does an Asian hornet look like?
Our UK hornet is the European hornet (Vespa crabro). It's big (between 2-4cms long) and has large jaws and a loud buzz. Because of its size, it is perhaps rather frightening but it is rarely aggressive to humans. Because of its awesome appearance it is often assumed to be the non-native Asian hornet.
The Asian hornet is blacker with a wide yellow/orange stripe on its abdomen. Its legs are yellow. It is also slightly smaller than the European hornet.
Views of the Asian or yellow legged hornet - all courtesy of Giles San Martin under a Creative Commons Licence
The European hornet is browner with much more yellow on its abdomen. Its legs are brown rather than yellow.
What to do if you think you have seen an Asian Hornet?
If you think you've spotted an Asian hornet you can report it via an online Non-native Species Alert.
Hornets are sometimes confused with wasps and other stripey insects. The app provides pictures of the Asian hornet, the European hornet, the Giant Wood wasp and the Hornet hoverfly to help narrow things down.
So, download the app. If you do see something suspect, take a picture. BUT don't annoy the insect by getting too close and certainly don't approach a nest!
Use the app to help confirm the identity then send the picture via the app to report the hornet to the Non-native Species Secretariat. This organisation co-ordinates the UK's response to invasive species such as the Asian Hornet and plants such as Giant Hogweed.
Keep your eyes peeled!