Beetle could become Britain's first extinction of new millennium

Efforts are being made this week to prevent Britain's first species extinction in the new millennium – of a beetle that was discovered only two years ago.

The streaked bombardier beetle is officially the UK's rarest insect, known from only one colony, on a brownfield site on the Thames estuary in east London. However, the site is about to be redeveloped for housing, and the rubble-strewn habitat it has found congenial is to be obliterated.

In an attempt to save the beetle, the developers have created an alternative site on the edge of the housing area, and this week volunteers from the London Wildlife Trust have tried to relocate the insects. Otherwise, disappearance looms for Brachinus sclopeta, which only a month ago was added to the UK's list of priority endangered species.

"This isn't an extinction in a remote rainforest on the other side of the world," said Jamie Roberts of Buglife, the invertebrate conservation charity. "It's happening right here on our doorstep, and could have been avoided if the site had been protected. It's very sad that a deliberate choice has been made to plough on with this development, regardless of the consequences to wildlife."

Bombardier beetles are among the insect world's more remarkable creatures. They possess an effective defence mechanism, which comprises their ability to fire a boiling chemical spray from the tip of the abdomen. This is fatal to other insects and discouraging to larger potential enemies, including humans.

There are about 250 species of bombardier beetle, but in Britain there was thought, until recently, to be only one – the common bombardier, Brachinus crepitans, which, despite its name, is scarce. But in May 2005, one of Britain's leading entomologists, Richard Jones, discovered the colony of streaked bombardiers while conducting a survey for the developers of the building site, which is near the Thames Barrier.

The insect was regarded as "missing, believed extinct", as it had not been seen in Britain since 1928, and before that the last reliable records were from the mid-19th century, so it immediately became Britain's greatest invertebrate rarity.

Mr Jones has been instrumental in persuading the company to create an alternative site nearby, and he has led the way in finding and moving the insects, so far having moved about 10. A search on Monday with a dozen volunteers produced only one more.

One of the difficulties with translocation is the beetle's life cycle; the larvae of bombardiers are known to prey on specific examples of other beetle species, especially of the ground beetle genus Amara, but it is not known which Amara species is the prey of the streaked bombardier. To provide for this eventuality, Mr Jones has also been translocating examples of Amara beetles from one site to the other.

Matt Shardlow, the director of Buglife, said the charity was sceptical of the possibilities of success, but wished the enterprise well.

A number of insect species are believed to have become extinct in Britain in recent years, including the short-haired bumblebee, last seen on the Kent coast in 1988, and the large blue butterfly, which died out in 1979. However, the large blue has been reintroduced successfully and is now thriving at a number of sites in the West Country.