A little over four years ago, I wrote the following words:
“There is more than one reason for the decline in the British bee population, for agricultural and horticultural pesticides can harm bees as well as pests, and intensive farming methods have reduced areas of natural countryside where bees can forage. But the varroa mite, which was first found in the United Kingdom in 1992, is blamed for much of the loss of bee numbers … a nasty little fellow if you are a bee, for this reddish-brown, eight-legged mite, which resembles a button around 1.5 mm in diameter, enters the honey bee brood cell and lays eggs actually on the bee larvae.”
Now, as if modern agricultural … and horticultural … chemicals and the varroa mite were not enough for the honey bee to cope with, another enemy is on the horizon. This is Vespa velutina nigrithorax, commonly called the Asian predatory wasp, which preys on bees and other insects. Native to China, this species of hornet has become an invasive species in several European countries since its arrival in France in 2005, probably in boxes of pottery imported from China. These hornets are larger than honey bees, with the queen up to 30mm in length … a little more than an inch … and the workers some two-thirds of this size. Fortunately, they are not usually aggressive towards people, although the females will sting if their nest is threatened. The problem here is that, if they do attack people, they usually attack in a group and, since several thousand hornets are commonly found in a single nest, serious problems can be induced by the multiple stings.
A much bigger problem, however, is that they prey on honeybees and a single hornet may kill five bees in a day. Since their arrival in France a decade ago, they have found conditions very much to their liking and there are now thought to be thousands of nests in the Aquitaine region and the surrounding départements. The Beekeepers Association of the Basque Country has confirmed that the Asian predatory wasp has spread to parts of Spain; and three years ago the first colony was reported in Portugal. Every area where this Asian invader has settled reports that it causes many problems for bees, for beekeepers and for other native insects; and the Department for the Environment, Foods and Rural Affairs in the United Kingdom has issued a warning to beekeepers in these islands to be constantly on the lookout for the pest’s arrival here.
The areas thought to be most immediately at risk are, of course, those parts of the United Kingdom which are closest to France and the Iberian Peninsula, in other words the south and south-east of England. But, since Vespa velutina nigrithorax is thought to have reached France in boxes of imported Chinese goods, there is nothing to say that a similar mischance will not bring the insect to Scotland; and apiarists here are being advised to learn how to recognise it and how they should report any suspected sightings. Anyone seeking further information will find a fact-sheet, pictures, lots of further information and instructions about proper procedures at http://www.nonnativespecies.org/home/index.cfm. Bee-keepers are also exhorted to sign up with BeeBase since, in the event that the Asian hornet … or any other threat to honey bee colonies … arrives, efforts to contain it will be jeopardised if the proper authorities don’t know where vulnerable apiaries are located; just type ‘beebase’ into an internet browser to find the site. And, while these recommendations are for beekeepers, I might remind all gardeners, householders and lovers of the great outdoors that disturbing any hornets’ nest is not the most sensible thing anyone has ever done; call your local authority to find out if it deals with problem nests or tells you to contact a private pest-control company.