Photograph: Ian Mears/Alamy
It was a stifling evening in July and Matt Phelps was out for a stroll, when a piercing, whirring noise stopped him in his tracks. As an ecologist, Phelps knows his fauna – and he could think of no UK creature that could emit such a sound.
“It was like the classic sound effect of a cricket in a film, a beeping sort of little trilling sound,” said Phelps, who works at Knepp Estate in West Sussex. He returned with entomologist Graeme Lyons to track it down. But the sound, though incredibly loud, “seemed to be all around us … it was very ventriloquial”.
The duo hunted for three hours. Night fell before they realised their quarry was, said Phelps, “literally below the ground where we stood”.
Sure enough, in a crack in the parched clay they made the first identification of a Verge (or Bordeaux) cricket (Eumodicogryllus bordigalensis) in the British Isles.
Once they announced it, other reports poured in. “It turns out there’s been this wave of them right at the moment when there was an enormous wildfire in Bordeaux,” said Phelps. “And it made you think: have some of these things fled the flames of southern Europe?”
Verge crickets are just one of many “first sightings” of insects on the UK mainland this summer. It’s been an “extraordinary flood”, he said. And it’s not just the professionals who are finding them.
Jackie Harmer, a retired secretary from North Cheshire, was one week into her new hobby of moth-trapping when she found an odd-looking creature native to the Iberian peninsula, Odice pergrata – a first for the UK.
And David Cousins, a city trader who collects moths by night at his home in north Essex, opened his box one June dawn to find a white moth with bluish markings.
“I just knew it was something really unusual,” he said. It turned out to be not just a new moth but “a completely undiscovered genus in Britain”. In north Africa and southern Europe it’s known as a spotted seal moth (Enolmis acanthella).
Then there’s Olly Mkeown, 18, in Truro, who didn’t even leave his room to discover what were pronounced in August to be the UK mainland’s first breeding praying mantises.
“I sat at my table doing some work and then one was crawling across my keyboard – and then I saw one on top of the chair and then I just started spotting loads all around the tables, chairs and then some on the walls as well,” he said.
McKeown’s sighting has subsequently been trumped by reports of others that predate his, in places such as the New Forest. The Cornwall Wildlife Trust said: “There are a few sites now where experts agree that the species has likely bred.”
Liam Crowley, a fellow of the Royal Entomological Society and entomologist at Oxford University, said that the simplest explanation of these shifts is that the world is warming up and insects are moving northwards.. But, he added, “there’s a lot of different dynamics going on and it’s hard to know the true cause”.
For example, insects that inhabited the UK a century ago may have gone locally extinct because of habitat destruction – only to return now if nature is restored, or if the climate crisis makes it the least-worst option.
Some arrivals may even be part of events unfolding since the ice age ended 11,700 years ago, said Crowley. “As humans, we tend to obsess and focus on our own timescales.”
He said there was also an explosion of migrating insects this summer.
“Every year there are trillions of insects arriving in the UK, migrating up from the continent and in some cases even northern Africa. They fly up high into the air streams and they use that as a bit of a lift.
“With the record-breaking heat, it’s been an absolutely bumper year [for migrating insects], particularly for very noticeable species.” Crowley highlighted hummingbird hawk moths and hoverflies, while others point to vast numbers of cicadas, striped hawkmoths, painted lady butterflies and clouded yellow butterflies.
“Some of these species are starting to breed and establish and potentially survive through the winter in the south,” he said.
Harry Witts, who discovered two new species in July, said he had mixed feelings about them. The excitement of discovery is balanced by the knowledge that “it’s only occurring because of climate change – a symptom of a very damaging force in our world”.
Witts, who works at the Essex Wildlife Trust, described the moment at Colne Point, Essex, when “this grasshopper with blue wings jumped out in front of me”. It was bigger than most UK grasshoppers, with much broader wings, which helped him identify it as a blue, slender-winged grasshopper (Sphingonotus caerulans). He thinks he was the first witness of its “natural arrival” on the mainland: other specimens found in Kent this summer were probably Channel tunnel stowaways, he said.
A few days later he and colleague Joss Carr found a new species of big-eyed bug (Geocoris megacephalus) in the same place, lurking on a piece of driftwood.
Crowley said that most of these arrivals, if they survive the winter and settle, will find their niche and get on with life and may even enhance the ecosystems.
“Occasionally,” added Phelps, “you’ll get something that becomes more problematic because it’s out-competing other species. But generally a lot of the ones that turn up by themselves don’t tend to do that.”
