This insect is not native to the UK and is NOTIFIABLE (*). It was accidentally introduced to the south of France in 2004 and has quickly worked its way up towards The Channel.
The first Asian hornet nest in the UK was found and destroyed in 2016, since when there have been isolated incidents.
The first Asian hornet nests in Hampshire were found in September 2018 along with nests in other parts of the UK. Other Asian hornet nests are likely, and vigilence is absolutely essential. Once established, this species will be very hard to eradicate.
It is an extremely aggressive predator and a colony of Asian hornets will decimate a colony of honeybees in a few hours. A single queen will establish a colony early in spring and will raise thousands of worker hornets and hundreds of young queens, which will come through winter and start their own colonies.
(*) 'Notifiable' means that, by law, you must report any sighting to the appropriate authority. In this instance, it is the Non-Native Species Secretariat (NNSS) - see below.