UK warned as plague of bee-eating hornets spreads north in France

• Pesticides and traps fail to halt steady colonisation
• British summer could be their downfall, says expert

Lizzy Davies in Paris
guardian.co.uk, Friday 25 September 2009 21.35 BST

For five years they have wreaked havoc in the fields of south-western France, scaring locals with their venomous stings and ravaging the bee population to feed their rapacious appetites. Now, according to French beekeepers, Asian predatory hornets have been sighted in Paris for the first time, raising the prospect of a nationwide invasion which entomologists fear could eventually reach Britain.

Claude Cohen, president of the Parisian region's apiculture development agency, said a hornet nest had been found this week in the centre of Blanc Mesnil, north-east of the capital.

If confirmed by further testing, the find will raise fears that the spread of the bee-eating Vespa velutina is no longer limited to the Aquitaine region near Bordeaux, where it is believed to have arrived on board container ships from China in 2004, and the surrounding south-west.

Denis Thiery, a specialist at the National Institute for Agricultural Research, said the hornets were likely to push on with a relentless colonisation of their adopted country until they become a common sight in vast swaths of France – and ultimately in other European states.

"We are seeing a real geographical expansion," he said, adding that an eventual invasion of southern England, which has a relatively mild climate the hornets would enjoy, could not be ruled out.

Biologists insist that this variety of Asian hornet, which can grow to an inch long, is no more ferocious than its European counterpart, although its stings, which contain more poison than those of wasps, can be very painful and can require hospital attention.

This summer swarms of the insects were reported to have attacked a mother and baby in the Lot-et-Garonne department, as well as pursuing passersby and tourists on bikes.

But the hornet's menace to human beings pales into insignificance in comparison with the destruction it wreaks on its chosen habitat. In south-western France, where its population surges each year, beleaguered beekeepers claim that they are being driven into the ground by the insect's destructive eating habits.

"We have literally been invaded," said Raymond Saunier, president of the Gironde department's beekeeping union. "In the past two to four years we have lost 30% of our hives. All it takes is two or three hornets near your hive and you've had it."

He added: "It's not just about us trying to make honey. What's even more serious is the effect they have on the pollination process [by killing so many bees]. It's really a disaster."

Faced with a demographic explosion which Thiery said had seen thousands of nests documented last year in the city of Bordeaux alone, entomologists are unsure of the best way to halt the hornets' seemingly unstoppable advance. Neither pesticides nor traps have proved particularly effective, largely because the creatures nest high off the ground in trees. The Vespa velutina has no natural predator on European soil.

Because of this, and a gradual shift in climate which experts believe could encourage the hornets to move north, many experts are adamant that the French scourge will at some point cross the Channel.

But the threat is not immediate, said Stuart Hind, head of the Natural History Museum's centre for biodiversity in London. "[A UK invasion] is very likely," he said. "It is entirely plausible. But it could be 10 to 15 years before they come knocking on our door."

But, he added, "If anything were to stop them it would be the good, old-fashioned British summers. They wouldn't cope well with heavy rain."

Insect invasions

March 2002
The pelargonium brown, a butterfly native to South Africa, was found to be eating its way through France by environmental research group Cemagref. It was considered a harmless addition to French insect life, although experts worried that it could oust local species. Thought to have ventured north because of warmer winters.

July 2005
Huge swarms of locusts ravaged the southern French region of Aveyron after a drought helped thousands of eggs to hatch. They wreaked havoc on hundreds of farms.

September 2009
In Britain's south-west, environmentalists were delighted by a surge in the population of one of the UK's most endangered butterflies. Experts recorded the second highest count of marsh fritillaries since weekly recording began in 1994.

http://www.guardian.co.uk/world/2009/sep/25/predatory-hornet-sighting-paris-france

See also: http://www.telegraph.co.uk/news/worldnews/europe/france/6049302/Tourists-warned-as-Asian-hornets-terrorise-French.html