Are Giant Asian Hornets swarming to the UK?

(Source: Wikipedia)

Panic stations!

Everybody shield your windows with netting, smother yourself in insect repellent and make sure that your next purchase is a bee suit because the biggest and deadliest hornet in the world is coming to the UK…

Well, that’s the conclusion you might have reached if you happened to be flicking through the Daily Mail in 2013. Midway through an article describing how a swarm of Asian giant hornets had wreaked havoc in Northern China, killing forty people, came the warning that giant Asian hornets would be arriving in England soon. The article’s transition from Asian giant hornet (which has a subspecies colloquially named “yak-killer”, is about thumb-sized and packs an unfair amount of venom) to giant Asian hornet (which is smaller than our native species, with a sting only slightly more serious than that of a bee) was seamless. In fact, if the Daily Mail wasn’t heralded nationwide for its integrity and unfailingly high calibre of journalism (*ahem*), one might almost accuse it of scaremongering.

Daily Mail bashing aside, you’ve probably already heard that Asian hornets might be making a beeline for England. The species, called Vespa velutina is thought to have arrived around ten years ago in France from China, stowed away inside a piece of pottery. Since then it’s spread to other parts of mainland Europe, including Spain and Belgium. It’s been anticipated for a couple of years now that the species might invade the UK and it’s looking even more likely after our particularly warm spring.

The English Channel, which in times gone by has protected us from Spanish conquest and Nazi occupation, unfortunately won’t do much to stop the Asian hornet. An inseminated queen is probably hardy enough to survive the 34km flight from France, and once she arrives, experts fear the spread may be fast.

The threat posed by the Asian hornet isn’t to humans and for every sensationalist headline there are the soothing words of entomologists. The Natural History Museum’s Hymenoptera curator, Dr Gavin Broad, says: “The sting of an Asian hornet is probably no worse than the sting from our native hornets, Vespa crabro. For most people, it hurts when you're stung, throbs for a few hours and then dies down.” Six people have died of anaphylactic shock after being stung by Asian hornets in France but this is over a period of ten years: in the UK on average four people a year die from insect stings – and it’s statistically far more likely that you’ll meet your end accidentally suffocating in bed, or drowning in the bathtub!

It is the UK’s honeybees, and other insects, which would bear the brunt of an Asian hornet invasion. Unlike our native species, which don’t make a habit of eating bees, a staple of the Asian hornet’s diet is honeybees. Although the hornet hunts a wide-range of arthropod prey, it tends to specialise if it encounters a honeybee hive and understandably so: the mass of available protein in a beehive makes it the hornet equivalent of a McDonald’s drive thru.

Experts worry that the hornets could upset the already dwindling population of honeybees. Asian honeybees coevolved with Asian hornets and therefore possess a string of efficient anti-predatory behaviours, the coolest of which is “balling”. This consists of honeybees massing around a hornet. Concentrated levels of CO2 and the high temperature created by honeybees collectively vibrating their wings asphyxiate and then roast the hornet alive! It’s already been shown that European honeybees are not able to display such efficient anti-predatory defence against the invasive species.

To this date there have been no sightings of the Asian hornet in the UK. If you want to do your bit to protect our honeybees then keep an eye out (Asian hornets are very distinctive since they are very dark brown, almost black, with narrow stripes), and report any sightings here.

#Hornets #Biology #GianlucaCerullo