Asian Hornet

Vespa velutina, sometimes known as the ‘Asian Hornet’, is an invasive non-native species from Asia and, if you find one, you must report it. The Asian Hornet arrived in France in 2004 and has spread rapidly. It is a highly effective predator of insects and active between April and November, with colonies growing to their peak size from August onwards. Every year, there is a dedicated Asian Hornet Week, in the second week of September, to raise awareness and encourage extra vigilance. In recent years, this non-native species has wrought havoc amongst bee keeping communities across western Europe and the Channel Islands, as it finds bees in hives an easy source of food for its brood. It also preys on other native pollinators and, as a result, has had a detrimental impact on fruit growers, vineyards and market gardeners. Asian Hornets have become an increasing issue in the Channel Islands, resulting in the need for considerable proactive search activities and the destruction of nests. Asian Hornets have also made their way across the Channel either through flight, accidental importation amongst pot plants, fruit and other goods or through hitching a lift with returning travellers.  In recent years, several colonies have been found and destroyed across English southern counties, including Gloucestershire (Tetbury 2016), and into the Midlands. Individual Asian Hornet queens have also arrived in other places. The resulting successful preventative measures have depended on the vigilance of beekeepers and well-informed members of the general public. Please download the Asian Hornet App onto your phone (see info below), as this is informative and enables you to report a sighting.

What to look out for (see photo below)

  • Entirely dark brown/black velvety body, bordered with an orange/yellow band
  • A wide orange/yellow stripe on the 4th segment of the abdomen
  • Known as the ‘yellow legged hornet’, as the legs look as if they have been dipped in yellow paint
  • Head black with an orange/yellow face

Additional information

Spring
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.

Summer
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.

Autumn
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 in the UK in September 2016, it is imperative that you make sure you know how to recognise and can distinguish them from our native hornet, Vespa crabro – a very helpful ID sheet and poster is available to help you:


ID Sheet
ID Poster
Postcard

Monitoring for the Asian hornet
The most important line of defence is for us to know what we’re looking for and to maintain active vigilance. Using the above links, you can download good visual information to enable you to identify species accurately. In September, look for them on fallen fruit and flowering ivy or hawking by bee hives. Also, keep an eye out for large nests in the trees, as the leaves begin to fall. 

Monitoring for arrival of the Asian hornet is also strongly encouraged throughout the UK, but especially in areas where likelihood of arrival is considered to be highest (S & SE England). All beekeepers are encouraged to monitor for the hornet’s arrival, and advice on how to make your own trap can be found in this fact sheet An Asian hornet monitoring trap and on the You Tube video How to make an Asian hornet monitoring trap The French have found that an ideal form of bait is a liquid concoction of one third white wine, one third beer and one third fruit syrup e.g., grenadine or the kind you squirt on ice cream.

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, it is important that damage to native wasps, hornets and any other insects is kept to an absolute minimum. Remember to check your traps regularly and to release non-target species. However, if you happen to trap an Asian Hornet DO NOT RELEASE IT and be very careful, as it has a very nasty sting.

If you think you’ve seen an Asian Hornet

If you need help to verify your sighting, local contact numbers can be found on the GBKA website. Alternatively, if you have your phone handy, try to take a photo and ensure you know exactly where you were at the time. Photos can either be uploaded via the

Or you can also report an Asian Hornet via:

If it is safe to do so, you can send in a sample to the National Bee Unit for examination to confirm identity (please note the specimen must be dead before sending it in). However, do not under any circumstances disturb or provoke an active hornets’ nest.