Guidance on Monitoring for Asian Hornets

This is an excerpt from an article by Gay Marris, PhD – National Bee Unit (NBU) which appeared in the May 2012 edition of Bee Craft

Everyone can help by looking out for this exotic pest

Vespa velutina – the Asian hornet (image courtesy of Jean Haxaire)

THE ASIAN HORNET, Vespa velutina, is an aggressive predator of honey bees and other beneficial insects. It has recently extended its geographical range from Asia to mainland Europe following an accidental introduction to France and is now also present in Spain and Belgium. Adult hornets are highly mobile; the rate of spread across France is approximately 100 km/year. There is now great concern that this exotic insect will reach the UK, either by hitching a ride on imported goods or simply by flying across the channel. Bee Craft has already published articles describing its biology and the risks of accidental import of the Asian hornet into the UK (September 2011, page 16; October 2011, page 35).

In April 2012, a Response Plan for dealing with the Asian hornet was finalised. Developed by the Food and Environment Research Agency (Bee Health Policy and the National Bee Unit, NBU), in consultation with Defra (Non-native Species Policy and its Non-native Species Secretariat (NNSS)), the Plan’s objectives are:

  • early detection, interception and prevention of establishment
  • nest destruction to eradicate localised outbreaks (if within a limited geographical area or areas)
  • development of longer term management plans where eradication is no longer possible due to the extent and number of outbreaks
  • provision of advice to beekeepers and all other stakeholders.

If you would like to read the full Response Plan, please visit the Asian hornet pages of the NBU’s BeeBase website:

The Important Message
The message to beekeepers from the NBU is given below. ¿ Monitoring for arrival is strongly encouraged throughout the UK but Bee Craft May 2012 Page 7 especially in areas where likelihood of arrival is considered to be highest (South and South East England).

  • Make sure you know how to recognise Asian hornets – a very helpful ID sheet can be downloaded from the BeeBase Asian Hornet page (see link above). The pdf can also be downloaded from a link at the bottom of this page.
  • Know where to report sightings:
  • Beekeepers and other members of the public should consider hanging hornet traps.
  • Spring trapping works!

Information from beekeepers in France, who are having to control hornet numbers, shows that in areas where traps are deployed in springtime, nest numbers are reduced by over 90%. In the event that Asian hornets become established here, springtime trapping will thus be a very useful management tool. ¿ Register on BeeBase, the NBU’s database of beekeeping statistics – this is always important, but in the event that the Asian hornet (or any other exotic threat to honey bee colonies) arrives here, efforts to contain it will be seriously jeopardised if we don’t know where vulnerable apiaries are located.

Making a Hornet Trap
This article explains how to make and use an Asian hornet trap. Hanging this simple device in your apiary will allow you to monitor for pest arrival.

The Efficiency of Hanging Traps

A variety of traps is available for catching adult hornets ‘on the wing’, including Asian hornets. Comparisons of various designs for use against V. velutina have shown that funnel traps work best.

Although field trials show that these capture considerable numbers of adult hornets (approximately 400 hornets/week/trap), they cannot be expected reliably to eliminate V. velutina from an affected apiary.

However, they are very useful as a first line of detection, for controlling hornet numbers and limiting damage, so thus have crucial roles in monitoring for arrival and, should Asian hornets arrive in the UK, in reducing impact and spread. Reports from France suggest that in areas where spring trapping has been used, subsequent numbers of Asian hornet nests are significantly reduced with two or three nests in trapping areas versus over 70 nests where no traps have been hung).

All 12 monthly issues of Bee Craft from 2012 are available to purchase in digital format from the Bee Craft shop.

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