by Richard Jones
I never got to see the hornet nest in Dulwich Park last year. By the time I had been alerted, it had been destroyed. My first thought was: interfering busybody or state-sponsored ecocide? Sadly, it was all too obvious that the nest had been targeted by the park’s own contractors, who removed it for the usual well-meaning, but ill-informed reasons of ‘health and safety’.
The hornet, Vespa crabro, is Britain’s largest wasp, and with queens reaching 50 mm (2 inches) long they are astonishing and awe-inspiring creatures, but with this size comes unease, or fear, and an undeserved reputation - for despite their bulk, hornets are also the most docile of wasps. They can sting, and I’m sure the venom is as potent as any, but it is the smaller yellow-jackets, that are much more likely to attack the innocent victim straying too close to the hidden nest.
The naturalist Edward Step recounts a lovely tale in his book on the bees, wasps and ants of Britain, of how he was slowly descending a precipitous slope and lost his footing; he grasped a small tree stump, only for it to come away in his hand and several dozen huge hornets emerge loudly into the air. He dumped it back roughly into position and backed quickly away to avoid their attack. He soon realized he was not being pursued by a squadron of irate insects, so gingerly crept back to see what they were doing. They were doing house repairs, trying to patch up the broken nest using the same chewed-wood paper with which they construct the brood combs. They ignored him completely, as they went about their business.
It is exactly right that Dulwich should be home to hornets, but it has taken them rather a long time to arrive here. Hornets are woodland dwellers, and they almost always make their colonies inside hollow tree trunks or rotten logs, unlike the ‘common’ wasps (actually several very similar closely related species), which tend to nest in holes in the ground or in lofts. Dulwich is one of the most heavily wooded areas of London, but for reasons that nobody is quite sure of, was part of a large segment of south-east England that remained hornet-free for many years. I grew up in East Sussex, and despite the large and ancient woodlands of the Sussex Weald, it too failed to support the hornets that were common in neighbouring Surrey and Hampshire. It was a mystery for sure.
Hornets have long been known in Richmond Park, Wimbledon Common and other parts of south-west London off into the Surrey Heaths and then down into the New Forest; this was their British heartland. But something happened in the early 1990s and the hornets of Central England started to spread. They arrived in Sydenham Hill and Dulwich Woods around 2001 and the London Wildlife Trust warden showed me the remains of a nest in a tree hole in Cox’s Walk. Since then I’ve seen the occasional foraging worker hawking after their fly prey around the compost bins of the allotments near Dulwich Golf Course.
As with all wasps, hornets are predators, catching flies and other insects to feed to their grubs, back in the nest. As autumn arrives, and there are no more young to rear, hornets will start to feed on fallen fruit, but unlike their small wasp relatives, they seldom bother the picnicker after jam sandwiches.
The photos taken shortly after the Dulwich Park nest was destroyed show mostly male hornets; these (along with new queens) only appear at the end of the year, as the nest matures and comes to an end. All of the workers (sterile females), which built and stocked the nest, captured prey, fed the grubs and cleared the colony of debris, die off. Eventually all the males die too, leaving only mated queens to survive through winter. They each find some dry nook, behind loose bark, under a large log, tucked deep into hedge-bottom leaf litter and hibernate, with their wings tucked tight under their bodies.
In May the queens emerge and each will have to start a new nest, from scratch, making the delicate paper comb and capturing insect prey until the first cohort of workers is reared through to help her. In the days after the infamous nest removal, I saw several large insects, which I thought must be hornets, flying about the streets of East Dulwich. My hope is that these will have been the queens, displaced early from the nest perhaps, but mated nevertheless, and that very soon Dulwich Park will be abuzz with hornets once again.