Asian hornets (Vespa velutina) are here, and they’re causing havoc. Once confined to the Far East, their native home, where they co-evolved with a whole range of species-specific pathogens, predators and prey, they arrived in France in 2004-5 in a shipment of goods from China.
Unspotted for a few years, they had time to establish themselves to the point where neither eradication nor confinement were possible. Fast forward to today, and they’re everywhere in France. I spent some time there this summer and saw them in trees, in bushes and flying around market stalls selling sugary foods. They’ve also made it to Belgium, Spain and Portugal.
The hornet problem
V. velutina is not just another hornet. Being non-native, they have no barriers to their spread other than geography, such as mountains which are few, and climate – which is warming: ideal for hornets. Their favourite foods consist of sugary substances at this time of year – they are after all big wasps – and other insects, especially honey bees (Apis mellifera).
Why honey bees? From the hornets’ point of view, a beehive is a delightfully concentrated source of both protein which can be transported back to the nest and fed to their larvae, and of sugar – ie honey – which the hornets themselves will consume.
Beekeepers in France have lost, collectively, some 30 per cent of their colonies to Asian hornets. They hang around outside beehives – a process known as hawking – and grab incoming forager bees. The hornet then flies the hapless bee to a nearby tree and dismembers it, discarding the head and abdomen and taking the meaty, muscle-filled thorax back to the nest.
The bees’ response to hawking is to form a guard at the hive entrance. It stresses the bees, and foraging can slow or even stop. Under heavy predation by Asian hornets, a honey bee colony can starve to death or be overrun by the hornets.
So Asian hornets threaten the pollination services that honey bees and other such insects provide. Being non-native, their voracious appetites also threaten the food sources of native species, such as the European hornet, Vespa crabro. Effectively, they’re occupying a similar ecological niche but are not constrained by native pathogens and predators. Nor do European and UK honey bees possess a co-evolved and therefore effective defence against V. velutina, which they do against V. crabro, which doesn’t present an existential threat.
The Asian hornet situation today
So that’s the problem in the round. More specifically, Asian hornets migrated from France onto the island of Jersey where the local government and a small army of volunteers have fought valiantly to identify, track and destroy nests. So far this year, they have destroyed well over 200 nests and counting.
In the UK, a small handful have been found and destroyed every year since 2016. We’ve been lucky. But this year, over 50 nests have been found in 44 locations – the vast majority in Kent. Most sightings have been around the south-eastern coast, which implies that they’re either being blown over from France by prevailing winds or hitching a lift on the massive volumes of cross-Channel traffic.
In Sussex, nests have been found in Newhaven and Eastbourne and only today – 25 September, as I write this – I received a call from a member of the public who spotted one in her garden in Ringmer. Unfortunately, she was not able to capture and photograph it before it flew away, but there’s little doubt that nests have been established in our county. Local beekeepers are on high alert, with hornet traps now being deployed.
What you can do
Download and install the Asian Hornet Watch app on your phone. It helps with identification and guides you through the reporting process. If you see or suspect you see one, don’t kill it: a dead hornet is just a dead hornet but a live one can be tracked back to its nest. Capture it instead.
Don’t be afraid of individual hornets. While they will defend their nests aggressively – so don’t get within five metres of a nest – on their own they are no more aggressive than other hornets, which makes them easy to capture using, for example, an upturned glass or jar and a piece of cardboard.
Once reported and identification is confirmed, professionals from the National Bee Unit, a department within DEFRA, will come and deal with it.
Asian hornets are very distinctive. They have yellow legs, an orange face and a dark, near-black abdomen with just a single orange stripe towards the rear. European hornets on the other hand are slightly bigger, and have dark legs, classic wasp-like black and yellow stripes, with the rest of the body a reddish-brown colour.
Finally, the sterling efforts of the teams on Jersey have thrown up a number of lessons, key among which is that vigilance by everyone is the most important factor for successful containment and eradication of this pest. Keep a look-out and let your friends, relatives and neighbours know what to look for.
So if you do see one, please capture and report it, don’t kill it. I can also help with identification or other questions you may have.
Asian Hornet Team Co-ordinator, Brighton & Lewes Beekeepers