Asian hornets arrived in the UK for the first time in 2016. This is bad news for our native insects. Jess Chappell, from the RSPB's nature policy team, tells us why:

Already threatened by habitat degradation, pesticides and a range of pathogens, our native insect pollinators aren't doing well.

Declines have been reported for all key insect pollinator groups including honeybees, bumblebees and hoverflies, yet these species play a crucial role, pollinating our wild plants and garden flowers, and ensuring that we have food to eat. And now a non-native species threatens to add to these declines, following the first confirmed UK sightings of the Asian hornet, Vespa velutina, last autumn.

An aggressive predator of native insects, the non-native Asian hornet poses a significant threat to honeybees and other already declining native pollinators. Originating in Asia, they arrived in France in a pottery container in 2004 and quickly spread. Then last September sightings in Gloucester and Somerset confirmed the species' arrival in the UK.

Asian hornet. Image by Jean Haxaire.

An Asian hornet

Work to locate nests began immediately, with a hive successfully destroyed. However, like many other social insects the queens survive the winter, emerging to create new colonies in the spring.

Therefore the possibility that mated queens are hibernating remains. This is, of course, not the Asian hornet’s fault – the introduction of non-native species is entirely a man-made problem – and is up to us to fix where possible.

And it’s not too late!

It’s possible to prevent Asian hornets from establishing in the UK, and a key part of this will be detecting any queens as they emerge from hibernation. This is where you can help – please report any suspected sightings, and with queens emerging as early as February, now is the time to be vigilant.

What does it look like?

There are several key features to look out for which will help you distinguish between Asian hornets, and our native European hornet, Vespa crabro:

  • The Asian hornet is smaller, with queens up to 30 mm, and workers up to 25 mm in length. European hornet queens can reach 35 mm
  • A key feature of Asian hornets 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 (see below)
  • Whereas the legs of European hornets are dark, Asian hornets have bright yellow tips to their legs
  • Asian hornets are only active during the day, unlike our native hornet which is most active at night

Asian hornet v European hornet.

How to report

If you think you may have spotted an Asian hornet please either email alertnonnative@ceh.ac.uk with location details and a photo if possible or use the online form.

Although they pose no greater danger to humans than a native bee or wasp, nonetheless it is important not to disturb an active hornet’s nest. Please take care not to approach a nest or provoke these insects.

European hornets

Newly introduced to Europe by people, Asian hornets threaten our native wildlife. European hornets, in contrast, are an integral part of our native wildlife, playing an important ecological role, and should be valued. Despite their unmerited fearsome reputation they’re not often aggressive, and will only sting when it feels threatened.

Highly social insects, hornets live in organised colonies comprising of a single queen - the only individual in the colony that reproduces - and a large number of workers.

In spring when the queen emerges from hibernation she constructs a nest of intricate design, mixing chewed wood and saliva to create multiple hexagonal cells, and lays a single egg in each.

European hornet. Image by Ben Andrew (www.rspb-images.com).

A European hornet

These eggs develop into workers who then carry out the work of the colony. These workers require a high energy diet, and feed on sugary liquid exuded from hornet larvae, in addition to sap and nectar. Nests tend to be built in tree cavities, or man-made structures which provide the nest with support in the same way, such as barns and sheds.

The species is found throughout Europe but has been directly persecuted by humans as a result of its reputation, and is consequently endangered in some countries, and even threatened with extinction in some areas of central Europe. Although once considered rare in Britain, European hornet numbers in GB have risen since the 1960s and the species is now fairly common in many parts of the south of England.

We’d love to keep it this way, so please keep an eye out for Asian hornets, and report any sightings.