Nature Studies

So here comes March, the month when, to our great pleasure, everything in the countryside wakes up. But there is one small creature about to awaken this spring which may cause us terrible trouble.

It is the Asian hornet, an invasive species from China and other parts of the Far East, which can devastate colonies of honey bees and have a seriously damaging effect on other insect life. It has come to Europe through global trade, having arrived in France in 2004 and spread to other continental countries. In Britain, although it has been recorded here since 2016, for several years it did not seem to be properly establishing itself—there was just one confirmed sighting of Vespa velutina in 2020, two in 2021 and two in 2022. However, last year there was a dramatic surge, with 78 confirmed sightings, the vast majority of them involving nests, from Kent to Yorkshire to Portland in Dorset (where two nests were found and destroyed last August.)

This sign of a real breakout by the wee beast has well and truly put the wind up Britain’s beekeepeers, and should be of concern to all countryside lovers. For as is often the way with invasive species, when it gets here from the other side of the world this large predatory wasp suddenly finds itself in an ecosystem whose native creatures have not evolved alongside it, and thus have evolved no defences against it—so it can play merry hell with them. And it does. Though it offers no more danger to humans than other members of the wasp family, for honey bees it can be mortal—at the height of the breeding season when they have numerous young to feed, Asian hornets will station themselves outside a beehive and intercept the bees returning with forage to feed their own young, and slaughter them. Experience from France and other European countries shows that whole colonies can rapidly be destroyed.

Concern among British beekeepers is acute, and many will shortly be taking part in what might be termed a spring offensive against the enemy. The pregnant hornet queens survive the winter by hibernating, and emerge from now on to found new colonies, themselves building what is known as a primary nest, where the first workers are reared; later in the summer a much bigger secondary nest is constructed, often high in a tree, which may contain 6,000 individuals. Many beekeepers are buying special traps, hoping to catch the queens before the first nest is built.

However, their special worry—that 2023 appears to have marked a breakthrough year in the colonisation of Britain by this dangerous invasive species—does not seem to be shared yet by the public or indeed by nature conservation bodies, apparently unaware that the Asian hornet can also wreak havoc among the populations of many other native insects. Duncan Fergusson, a Dorset beekeeper with hives in the village of Sydling St Nicholas, said to me: “It’s frightening, because unlike the varroa mite, say, which only affects honey bees, the Asian hornet is going to devastate wildlife on a much wider scale if it is allowed to get established. That’s the big message people are missing.” Certainly, the anecdotal evidence from France is that this is true.

Britain’s insect populations have crashed anyway in recent decades, largely because of the tide of pesticides spread on the land by intensive farming, with an enormous knock-on effect on other wildlife, especially birds—it has led to the near-extinction of much-loved insectivorous species such as the spotted flycatcher and the grey partridge. The last thing our beleaguered biodiversity needs is another specialist insect-remover. So it is fervently to be hoped that wildlife organisations will wake up to the danger and help the beekeepers. In fact, anyone can help. Asian hornets are smaller and darker than our native European hornet, Vespa crabro. The queens are about 30mm long (or an inch and a quarter) and the workers about 25mm (about an inch). They have a broad yellow-orange stripe across the dark body near the tail, and distinctive yellow legs—see the picture above—and if you think you have spotted one you can download and use the Hornet Watch App, or simply email (attaching a photo if possible) and the experts will take over.

Last year a major UN report proclaimed: “The severe global threat posed by invasive alien species is underappreciated, underestimated and often unacknowledged.” This one is on our doorstep. Right now. Take heed.