Bee Health Improvement Partnership (BHIP) Annual Report 2024

Non-native invasive species

Yellow-legged hornet, also known as the Asian hornet

Yellow-legged hornets are aggressive predators of several species, including honey bees and other pollinators. In August 2024, Defra made a change in how they refer to the Asian hornet (Vespa velutina nigrithorax), opting to call it the Yellow-legged hornet (YLH). This decision followed consultation and discussion and is seen as a more accurate and descriptive name for the species. The Scottish Government has aligned with this shift to ensure consistent messaging across the UK, and it is hoped this will help reduce the number of erroneous reports.

2023 saw a significant increase of YLH sightings in England where a record 72 nests in 56 locations were identified, principally in the south of England. In 2024, there have been 71 credible sightings and 24 nests found. To date, no nests have been discovered in Scotland. There was a credible sighting of a Yellow-legged hornet at a supermarket distribution centre in the Central Belt in 2017. Unfortunately, the specimen was not conserved and, as a result, was not submitted for official laboratory confirmation.  

While there is no evidence to suggest that these hornets are established in the UK, the NBU and the Animal and Plant Health Agency (APHA) continues to actively work to eliminate the Yellow-legged hornet in England. In Scotland, there is no formal surveillance program because there are no identified critical risk points. However, with the increasing number of sightings and confirmed nests in England, including in northern regions like Lancashire and Yorkshire, the BHIP continue to raise awareness in Scotland and encourage extra vigilance to increase the likelihood of detection should this non-native invasive species arrive in Scotland.

The public is most likely to spot a Yellow-legged hornet in autumn when their population is at its peak. To raise awareness, the BHIP launched a digital newsletter to inform people how to identify and report sightings. The newsletter also encourages the public, especially beekeepers and gardeners, to participate in the UK Pollinator Monitoring Scheme (POMS) and help with targeted observation. As part of this effort, gardening and horticultural communities were urged to remain vigilant, particularly as Yellow-legged hornets are often found around fallen fruit, compost heaps, and ivy nectar in the autumn months.

The communication campaign had a broad reach, including publications in the SBA and Scotland Grows magazines, a social media push, and newsletters sent to local associations in Scotland. It was also supported by SG Plant Health colleagues, who shared the information with horticultural businesses, and NatureScot, who disseminated the message through their non-native species teams. A copy of the newsletter can be found on BeeBase.

Additionally, the SRUC Bee Health Advisor gave talks on Yellow-legged hornets to various groups, including beekeeping associations and a gardening group during 2024.

During August and September, Bee Health Inspectors spent a week in Kent with NBU colleagues providing assistance in the field and learning the most up to date track and trace procedures for Yellow-legged hornet. In addition, SASA staff attended a training session with their English counterparts in FERA, covering the process of dissecting and analysing a Yellow-legged hornet nest.

The risk of an incursion of the Yellow-legged hornet in Scotland is, unfortunately, likely at some point in the future. However, this close co-operation with our English counterparts, who now have had ample experience in tackling incursions, ensures we are trained and ready to deal with one should it occur.

Following the publication of the Scottish Government’s Yellow-Legged Hornet Contingency Plan, SG officials carried out Exercise Melliseus to test the governance elements of the Plan for the control of a credible Yellow-legged hornet sighting. Feedback and lessons learned are being collected following the exercise and will be used to identify improvements in procedures employed in managing an incursion.

In 2025, SG officials will also be doing a practical Yellow-legged hornet contingency exercise in the field to test standard operating procedures and ensure measures are assessed before an incursion.