A French spider-eating wasp has been found for the first time in Britain, wildlife experts announced today.
The creature caused a huge buzz in bug watching circles after it was found breeding in a quarry next to the headquarters of the Royal Society for the Protection of Birds in Bedfordshire.
RSPB staff have worked with the quarry’s owners, Lafarge Aggregates Ltd, to create a custom-built habitat ideal for rare insects.
Episyron gallicum, as the wasp is known to entemologists, was discovered after Lafarge agreed to fund a survey of the quarry to see if the work had been successful in attracting insects to the site.
It turned up a huge variety of unusual bugs on the restored parts of the quarry site, including the spider-munching newcomer.
The wasp is normally a Mediterranean species and the nearest it has been to Britain before now is central France.
Episyron gallicum seeks out spiders which hunt their prey on the ground rather than building webs. It is incredibly nimble, dancing around its prey to outwit it before paralysing it with a quick sting.
The helpless spider is then sealed in a tunnel with a wasp egg laid on it. When the larva hatches, it uses the unfortunate arachnid as a source of fresh food.
Peter Bradley, site manager at the RSPB reserve, said “It’s entirely new to this country. It is a species of specialist wasp that lives in dry and loose sand. I’m pretty sure it’s living there and breeding.”
Mr Bradley was convinced the work done by the RSPB had made it possible for the creature to make its home on this side of the Channel.
He said: “What usually happens with quarries is they are great for these rare invertebrates for a short period of time, while there is lots of disturbed dry sand and cliff faces. But after a few years they get filled in or nicely profiled by grass, or the cliff face runs out of coarse material.
“The idea here was that we create a structure that naturally creates new areas of loose sand by gradually eroding.
“The results were pretty amazing really. There were lots of real rarities there. This is a way of managing quarry restoration that is exceptionally good for interesting wildlife. It’s obviously worked very well here.”
Gavin Broad, a zoologist with the Biological Records Centre, said climate change may have combined with work done at the quarry to create good conditions for the colonist.
He said: “There are all sorts of species in Europe that aren’t here and various insects have been changing their ranges since the last ice age. The change to warmer summers and winters is going to help them.
“A lot of insects are constantly getting blown about all over the place and will often end up in unsuitable places but as soon as the weather is right they will stay on. The quarry work means it is absolutely ideal for this kind of wasp. They love warm, sandy banks.”
Mr Broad said there are already 40 native species of spider-hunting wasps adding: “It’s quite big news in that no one has found any new ones for a few years.”
In all 135 species were found at the quarry, including everything from bees, wasps and flies to earwigs, ants, crickets and grasshoppers.
Among the other stars of the survey were an endangered robberfly, which was previously confined to The Brecks area of Norfolk and Suffolk, a ground nesting, weevil-hunting wasp and several kinds of rare bees.
Tim Deal from Lafarge said: “It’s great that we have found something of national interest, very possibly as a result of the restoration work we have done at the quarry.
“We are very pleased to see that what looks like quite a barren landscape actually has quite a lot going on. The report has shown up some really good evidence of biodiversity, not just in extent but quality too.
“We would feel slightly disappointed to have funded the work and found nothing.”
Mr Deal said Lafarge is committed to restoration work at its sites.