Suffolk conservation officer urges people to keep their eyes peeled for UK’s biggest bug
By any standards, he has a mighty pair of jaws. At up to a third of his entire length, these formidable mandibles could leave even a great white shark feeling green with envy.
Tearing apart prey, though, is never on his mind. In fact, he cannot eat at all, only sip a little moisture with his feathery tongue.
But those massive jaws come in very handy when fighting off rivals for his sole purpose in life. From the moment the male stag beetle emerges from his underground lair, he has one thing on his mind … sex.
For the six or so weeks of his adult life, he will exist only to mate as many times as possible. Then, when he finished, he will die.
Males engage in dramatic wrestling matches to compete for females – even seizing opponents in their jaws and hurling them away in moves to rival the sport’s human stars.
Females also live only long enough as adults to mate and lay their eggs.
Stag beetles, so named because their huge jaws resemble deers’ antlers, are Britain’s biggest insects.
They are a rare and threatened species throughout northern Europe and a conservation priority in the UK.
Although they are in decline, the true UK population is not known … and this is where a leading conservation charity would like us all to help.
The People’s Trust for Endangered Species (PTES) has just begun its annual nationwide survey of stag beetle sightings.
Suffolk is one of the counties where the impressive-looking creatures – males are up to 8cm long and females often half that size – are most often found.
So the message is, keep your eyes peeled and, if you see one, let them know.
Laura Bower, conservation officer at PTES, says they tend to be out and about on warm summer evenings, although they can be spotted at other times.
June and July are prime times for sightings as the adults emerge from underground and start their mission to ensure the next generation. By August, most will have died.
“We do get reports at any time of day, but mostly it’s warm, sultry still evenings, said Laura.
“We had more than 650 sightings from Suffolk last year. I think more people are aware of the survey now. Locations included Hadleigh, Framlingham and Bungay, but they could be seen anywhere in the county.
“There were a lot of sightings in Ipswich, a lot of them in parks and gardens.
“That’s possibly because people aren’t out looking in woodlands in the evenings. Or maybe people have a lot of rotting stumps or railway sleepers, or have put down wood chips in their gardens.
“If they are in contact with the soil, they rot down, and that’s a larvae habitat.”
Stag beetles used to be found over a much wider area of the UK. Now, they are mostly concentrated in the south east of England, including Suffolk and Essex.
Last year Hampshire recorded the most sightings, with more than 2,000. It might seem surprising but Greater London was second with 1,781 – possibly because more people saw them out while walking in public parks.
The beetles live only around two per cent of their lives as adults, with the rest spent hidden from view as they chomp their way through decaying wood. They are harmless to living trees and plants.
“The female lays her eggs next to rotting wood underground,” said Laura. “When the larvae hatch, they make their way into the dead wood, where they live for around six years.
“When they emerge as adults, they only live four to six weeks. They don’t eat at all. They have a feathery tongue and can only take in moisture from tree sap or rotting fruit.
“They build up their fat reserves as a larva – a really big cream-coloured grub with an orange head – which will start small and grow to the same size as the adults.”
After about six years, the larva leaves the wood and makes a cocoon in the soil. In late summer or autumn, it turns into a pupa, which, after a few weeks, becomes a fully grown beetle.
It stays underground until the next summer, when it comes out as an adult.
“If you dig up a larva or a pupating beetle, just put it back where you found it, and cover it up,” Laura says.
“Male adults can be 8cm long. The females are smaller, up to 5cm, and have very small ‘antlers’.
“They have a black head and thorax and their wing cases are shiny chestnut brown – quite a handsome and striking beetle.
“The males fly quite a lot. Because they are big beetles, they look quite clumsy and bumbling in flight. When they fly, they look a bit like a tiny helicopter.
“We sometimes get reports confusing them with cockchafers or lesser stag beetles, which are much smaller.”
Lesser stags are black all over with matt wing cases. Cockchafers, also known as maybugs because of the month they often emerge, are only about 3cm long, and have distinctive fan shaped antennae.
The PTES has been doing its stag beetle survey for 25 years. “We don’t really know about the numbers historically,” said Laura. “We do know they have undergone a range decline but that looks stable over the 25 years.
“We are also asking people to take part in our additional weekly survey. That will mean we can tell the numbers over time and how they are changing. We have an identification guide on our website.
“If you want to encourage stag beetles, leave a bit of dead wood around, especially in contact with soil, or underground,” she added.
This could be the stump of a dead tree, or a log pile. Nature lovers are also invited to register their insect-friendly efforts with the charity on its website, which also tells you how to build a log pile.
You could use prunings from your own garden, or ask neighbours for theirs. But never take wood from woodlands, because that would destroy what is already a precious habitat.
Even if you can’t see any creatures in your log pile or tree stump, they will still be there. It might not be stag beetles but something else will gratefully call it home.
“You probably won’t see wildlife because you can’t tell if they’re there without disturbing them, and you don’t want to do that,” said Laura. “But even if it’s not stag beetles, there will be other species using it.”
The PTES was founded more than 40 years ago. “At first, it was just about grant giving, and supporting other people’s conservation projects and research across the world.
“That is still the main thing that we do. But now we also do our own surveys, including of dormice and hedgehogs, focusing on UK species. It’s a growing charity … still small, but we do have quite a big reach.”
The work is funded by individual backers, legacies, business supporters, and a shop on its website. It also has two nature reserves, an old orchard and an ancient woodland.
