Authorities in Britain are warning members of the public to be vigilant, as the invasive Asian hornet emerges from hibernation. Queens emerge in April and May. The hornet feeds on bees and other wasps with devastating effect. It can also be fatal to humans as its larger size and ability to repeatedly sting can induce anaphylactic shock, but it is considered more of a threat to native bees and wasps than to humans.
Just one sighting has been confirmed in Ireland, a stowaway in the luggage of a woman travelling to Cork from France. However, having made itself at home on the continent and in Britain, it seems just a matter of time before it crosses the Irish Sea.
The Asian hornet is believed to have arrived in France on a shipment of pottery from China in 2004. It quickly spread across mainland Europe. Since then seven people have reportedly died as a result of being stung. This usually only happens when a hive feels threatened. A sighting was confirmed in Gloucestershire in England last year and a nest was subsequently destroyed in September by Defra officials.
At that time Nicola Spence, deputy director for plant and bee health with Defra, said: “I am pleased our well-established protocol to eradicate Asian hornets has worked so effectively. We remain vigilant, however, and will continue to monitor the situation and encourage people to look out for any Asian hornet nests.”
Flying at speeds of up to 25mph, once established an Asian hornet colony can attack bees within a 60 mile radius. The hornet can have severe impacts on honey production, as honey is one of its favourite meals. It waits at the hive entrance and bites off the bees' heads as they emerge. A few hornets can kill an entire colony of bees in a matter of hours. They then enter the hive and steal the bees' honey.
In its native Asia local honey bees have evolved numerous coping mechanisms, such as darting quickly in and out of the hive when a hornet is detected nearby. They also have a method of suffocating the hornets by surrounding them in a tight ball and buzzing together to raise the temperature within the ball. Some European bees do this too, but they don't manage to raise the temperature enough to kill the Asian hornet.
The Asian hornet, Vespa velutina can be recognised mostly because of its large size. Workers measure about 20mm, compared to 12mm for the western honey bee, Apis Mellifera. Queens are considerably larger. All have bright orange heads, black antennae and golden striped bodies, with yellow legs.
The Department of Agriculture published this leaflet in 2015.