St. Andrew's Douzaine, Guernsey

Asian Hornet Watch 2018

Asian Hornets


Now that Summer has arrived, we are now seeing a lot of insect activity; an Asian Hornet queen was captured earlier in the year near the Longfrie and three workers were trapped in Câtel, close to the border with St Andrew; nests have also been recently been discovered in the Vale and more recently near the Longfrie in St Peter’s.  It is therefore inevitable that other Asian Hornet nests are now being established around the Island. If Guernsey is to preserve its essential local honeybee population and other insect life, it is vital that everyone keeps an eye open for these unwanted, predatory immigrants, and their nests.

****** 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 .

Towards the end of last Summer and into the autumn, reproducing females and males  emerged from their nests to mate, abandoning the workers remaining in the nest to die off as the weather got colder; the old nests aren’t normally reused by the hornets. The fertilised, descendant queens will have over-winter either singly or, perhaps in small groups, in insulated, sheltered cavities, under bark, in tree hollows and in buildings. It is these survivors which will now be actively building new nests to establish new powerful colonies. Until now, the number of Asian Hornet nests found in the Bailiwick has been limited, but this situation is likely to deteriorate if we don’t remain vigilant and keep numbers in check.

Honey bee colonies 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; likewise, the last thing we need is to lose our essential crop pollinators.

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.

The Asian hornet is an aggressive predator of many types of insect but on average 30% of its diet is made up of honeybees. The Asian hornet is therefore a major threat to our biodiversity, pollinator insects, and bee keeping activities. The States of Guernsey is encouraging anyone who thinks they have seen an Asian hornet or, found an Asian hornet nest to report it to Agriculture, Countryside and Land Management Services (ACLMS):

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 –