Vespa velutina, the yellow legged hornet, commonly known as the Asian hornet, is native to Asia and was confirmed for the first time in the South West of France in 2004. It was thought to have been imported in a consignment of pottery from China and it quickly established and spread to many regions of France. The hornet preys on honeybees, and disrupts the ecological role which they provide and damages commercial beekeeping activities. It has also altered the biodiversity in regions of France where it is present and can be a health risk to those who have allergies to hornet or wasp stings.
In 2016, the Asian hornet was discovered in the UK for the first time, in Tetbury. After 10 days of intensive searching, the nest was found and later destroyed. On the same day, a single hornet was discovered in a bait trap in North Somerset. Genetic analysis has confirmed that the hornet nest found in Tetbury and the dead hornet found in North Somerset were of the same genetic population (Vespa velutina nigrithorax) as those which came from Eastern China to France. Although we cannot rule out the hornet arriving directly from the same area in China, it is believed to be is highly unlikely.
The following year, in 2017, another Asian hornet nest was discovered in Woolacombe by a vigilant beekeeper who reported seeing Asian hornets hawking and hunting in his apiary. A nest was subsequently discovered and destroyed.
The number of sittings remained static until a large increase of 78 confirmed sightings in 2023, particularly in the Kent area, taking the total number of sightings in the UK to 101.
The BBKA are reacting to this increase and held an online Asian Hornet Wash Up meeting on 27th Nov’23. The BBKA Asian Hornet Committee subsequently met on 4th Dec’23 to discuss the actions identified and progressed a series of actions.
Appearance and biology of the Asian hornet
The Asian hornet is smaller than our native hornet, with adult workers measuring from 25mm in length and queens measuring 30mm. It’s abdomen is mostly black except for it’s fourth abdominal segment which is a yellow band located towards the rear. It has characteristical yellow legs which accounts for why it is often called the yellow legged hornet and it’s face is orange with two brownish red compound eyes.
After hibernation in spring, the queen, usually measuring up to 3 cm, will emerge and seek out an appropriate sugary food source in order to build up energry to commence building a small embryonic nest. During construction of the nest, she is alone and vulnerable but she will rapidly begin laying eggs to produce the future workforce. As the colony and nest size increases, a larger nest is either established around the embryonic nest or they relocate and build elsewhere.
During the summer, a single colony, on average, produces 6000 individuals in one season. From July onwards, Asian hornet predation on honeybee colonies will begin and increase until the end of November and hornets can be seen hovering outside a hive entrance, waiting for returning foragers. This is the characteristic “hawking” behaviour. When they catch a returning bee, they will take it away and feed off of the protein rich thorax; the brood requires animal proteins which are transformed into flesh pellets and then offered to the larvae.
During autumn, the nest’s priorities shift from foraging and nest expansion to producing on average 350 potential gynes (queens) and male hornets for mating, however, of these potential queens, only a small amount will successfully mate and make it through winter. After the mating period, the newly fertilised queens will leave the nest and find somewhere suitable to over-winter, while the old queen will die, leaving the nest to dwindle and die off. The following spring, the founding queen will begin building her new colony and the process begins again.
In light of the Asian hornet finding its way to the UK it is imperative that you make sure you know how to recognise and can distinguish them from our native hornet, Vespa crabro. The BBKA have a very useful identification page.
Monitoring for the Asian hornet
Monitoring for arrival of the Asian hornet is strongly encouraged for all beekeepers throughout the UK, but especially in areas where likelihood of arrival is considered to be highest (S & SE England). Should you wish to monitor for the hornet’s arrival, some helpful tips and advice on how to make your own trap can be found an the BBKA Asian Hornet monitoring trap page.
Information from beekeepers in France shows that nest numbers can be reduced over time by > 90% in areas where traps are deployed in springtime coupled with IPM techniques and nest location and destruction. Should the Asian hornets become established in the UK, springtime trapping will thus be a very useful management tool. When hanging out traps, please remember that it is important that damage to native wasps, hornets and any other insects is kept to an absolute minimum.
How to report sightings
If you think you have seen an Asian hornet, please notify the Great British Non Native Species Secretariat (NNSS) immediately. In the first instance sightings should be reported through the free Asian Hornet Watch App, available for Android and iPhone.
Other methods of reporting the hornet also include using the NNSS online notification form. Finally, you can send any suspect sightings to the NNSS email address email@example.com . Where possible, a photo, the location of the sighting and a description of the insect seen should be included.
FDBKA is very pro-active in Asian Hornet monitoring, led by the Asian Hornet Team Leader, Mark Fisher who is also able to respond to sightings. Mark leads a team who all have completed an On-line Identification Training Exercise.
The association is also fortunate to have within our membership Alan Baxter who is the Asian Hornet Coordinator for Hampshire Beekeepers’ Association. Alan has written the Contingency Plan for Hampshire.
See also Alan’s up to date guidance for Monitoring and Trapping in Hampshire.
If you would like to know more about the Asian hornet or any other Invasive Species, the NNSS website provides a great deal of information about the wide ranging work that is being done to tackle invasive species and tools to facilitate those working in this area.
It is also important that beekeepers sign up to BeeBase. In the event that the Asian Hornet (or any other exotic threat to honeybee colonies) arrives here as efforts to contain it will be seriously jeopardised if we don’t know where vulnerable apiaries are located.