St. Andrew's Douzaine, Guernsey

Asian Hornet Watch 2019

Asian Hornets


The first known sighting of an Asian hornet (Vespa velutina) in Guernsey was in March 2017. Asian hornets have spread throughout Europe after arriving in Southern France in a consignment of pottery in 2004.

Towards the end of last Summer and into the Autumn, reproducing females and males will have emerged from their nests to mate, abandoning the workers remaining in the nests to die off as the weather got colder; the old nests aren’t normally reused by the hornets. The fertilised, descendant queens over-winter either singly or, sometimes in small groups in insulated sheltered cavities, under bark, in tree hollows and in buildings. This cycle in now about to be repeated so the situation is likely further to deteriorate.

Asian Hornet queens were found early in 2018 near the Longfrie and Capelles and three workers were found in Câtel close to the border with St Andrew.  As well as the nests which were subsequently discovered in the Vale, St Peter’s and St Saviour, other nests were found near the PEH and in St Peter’s.  Nests have been found 15 metres up a tree, in a shed, in a hedgehog house and deep in brambles, so Asian Hornets seem to be very opportunistic in their choice of location for nest building. As 2019 progresses, there will probably be many new nests waiting to be found and these will need to be dealt with quickly by the authorities in order to minimise impact on our indigenous insect population. Several queens have already been detected in Alderney and Jersey. As at 17th June 2019, nine queens (plus one worker) have been caught in traps around most parts of Guernsey; one primary nest has also been found.

Honey bee colonies and all our indigenous insect life  have been under very considerable pressure in recent times due to various pests and diseases and the last thing they now need is predation from the aggressive Asian Hornet.  The Asian hornet is an aggressive predator of many types of insect, but on average over 30% of its diet is made up of honeybees. The Asian hornet is a major threat to our biodiversity, insect life and and bee-keeping activities; is is essential that that we do not lose any our essential crop pollinators.  It was hoped that a new “radio tracking” system (jointly sponsored by the Channel Islands Co-Operative Society and the States of Guernsey) would prove to be a useful tool to enable nests to be found by tagging trapped worker hornets with radio trackers; unfortunately the micro transmitters have so far, proved to be too heavy for hornet workers to carry in flight.

Now that the weather has warmed up, over-wintered queens will, by now have established new nests and will be breeding fast. This year, Asian Hornets have already been seen in St Peter Port, Forest and Castel.  As well as keeping an eye open for small “primary nests” now and large nests throughout the year, it is also important that everyone should also look out for flying workers and if seen, ascertain the direction of travel if at all possible. Once Asian Hornet queens have finished flying, bait stations are another tool which can be used at suitable locations so that foraging workers can be monitored and hopefully, their direction of flight paths recorded; this information can be useful in ascertaining nest locations.

It is vital that everyone assists the local bee keeping community and volunteers, by keeping a careful watch for these unwanted, predatory immigrants, and their nests.

Spring Queening

The Asian Hornet Strategy aims to keep the population of Asian hornets as low as possible. The first step of the comprehensive island wide control programme is the Spring Queening Project”, to trap queen Asian hornets as they emerge from hibernation in the spring. Trapping queens before they have the opportunity to raise their young and build huge nests is the main priority. A large nest can hold 5,000 hornets which will cause significant harm to our native insect populations, and could pose a public health risk if the nest were to be accidentally disturbed. Householders, beekeepers and landowners have put up and are monitoring traps all around the island. The same systematic method of trapping has been rolled out across Alderney, Herm and Sark. For more information please contact the Asian Hornet Team on tel: 234567, or email

Please be careful NOT to mistake (or injure) the harmless, but very interesting Hornet Hoverfly with the Asain Hornet. See bottom of page for
photo of Hoverfly Hornet Volucellazonaria.


What do Asian hornets look like?

Asian hornets have a distinctive velvety black/dark brown thorax. The abdomen is also black/brown with the abdominal segments bordered with a fine yellow band, only the fourth abdominal segment is almost entirely a yellow-orange. The legs are black/brown with yellow ends and the head is black with an orange-yellow face. A typical worker hornet is approximately 22mm (1 inch) in length.



Courtesy The Animal and Plant Health Agency (APHA), Crown Copyright

There is further information about the biology and life cycle of the Asian hornet on the National Bee Unit website:

Are Asian hornets dangerous?

As with bees and wasps, the Asian hornet has a painful sting. The sting of an Asian hornet is no more harmful than that of a bee or wasp although if a person is allergic to bee or wasp stings they are also likely to react to the sting of an Asian hornet. However Asian hornets may act more aggressively than most other indigenous bee and wasp species if their nest is threatened so it is important not to provoke them deliberately. When foraging for food away from the nest the Asian hornet is no more aggressive than a normal wasp.



What do I do if I think I’ve seen an Asian Hornet?

Anyone who thinks they have seen an Asian hornet is asked to  photograph the insect if possible, note the location and watch it long enough to determine the direction of travel as this may be helpful in locating a nest. ACLMS is mapping Asian hornet sightings to help in the search for nest sites, so providing an accurate location with your sighting is very helpful. Nests are most commonly found high up in trees, although may also be found attached to or in buildings. Please report the location of any insect or nest found to ACLMS (tel: 234567, or email Sightings can also be submitted through the Asian Hornet Watch app, which can be downloaded for free from the both the Apple ( and Google ( app stores – search for ‘Asian Hornet Watch’. The app also shows how to identify the Asian hornet from other similar looking species and photos can be uploaded directly from a mobile device. Your sighting will be forwarded to ACLMS automatically.

It is not urgent that a nest is destroyed immediately, but it must remain undisturbed whilst plans are made by the States of Guernsey for the safest way for it to be destroyed by a nominated pest controller. Confirmed sightings will be vital to help us find nests and eradicate the Asian Hornet from Guernsey.

Please note this is not to be confused with the Mandarin or Giant Asian hornet (Vespa mandarinia) which is very much larger and is found in China. It has not been found in the UK or Europe.


Please also be careful NOT to mistake or, injure the harmless, but very interesting Hornet Hoverfly with the Asain Hornet. The attached photo is published with kind permission of

Chris Raper

Hoverfly Hornet Volucellazonaria (c) Chris Raper

As a matter of general interest, this large harmless hoverfly which mimics hornets, leads a very interesting and remarkable life. For further information, on this and masses more too, go to –