Pine hoverfly gets a rotten lifeline just before it takes flight for good

Published on Tuesday 16 June 2009 22:45

AN INSECT on the verge of ex- tinction in the UK could make a comeback due to a reintroduction project in a Scottish forest.

There are only about 250 pine hoverflies left in the wild in Scotland.

The distinctive red and black insect is in a perilous state due to its specialised breeding requirements.

The beastie, the size of a small bumblebee, requires rotting tree stumps that contain pockets of water to breed, but a lack of old trees has left their continued existence under threat.

Now Scottish Natural Heritage is spending 60,000 on a three-year project to try to boost numbers of the beleaguered bug.

Twenty pine hoverflies have been reared at a field laboratory in the grounds of the Rothiemurchus Estate near Aviemore, in the heart of the Cairngorms National Park.

It is hoped the insects will breed in artificially created tree stumps nearby.

If successful, it will be the first time the bugs have bred in that area for 60 years.

Holes have been cut into tree stumps and filled with wood chips. When filled with rain water they mimic the natural rotting stump habitat in which pine hoverfly larvae live.

Iain MacGowan, an SNH officer involved in the project, said: "The pine hoverfly is a characteristic part of a pinewood just as much as the red squirrel or the capercaillie. It has been in our pine forests for the last 10,000 years or so. It's as much a part of it as these more iconic species."

Pine hoverflies are now only known to live in two sites in Britain. It is thought the bug disappeared from many sites after extensive felling of trees during the Second World War.

"It could be argued the pine hoverfly is a victim of its own specialised breeding cycle," added Mr McGowan, "as it needs large, old rotten tree stumps more than 40 centimetres in diameter to breed. Now the lack of such large trees in native pinewoods is a problem not only for this hoverfly but also for other insects and birds. We need to think about managing our forests to help this little insect, as well as all the better known species."

The reintroduction of the species is the result of joint working between Scottish Natural Heritage, the Rothiemurchus Estate, and PhD scientist Ellie Rotheray.

Environment minister Ros-eanna Cunningham called it a "welcome and much-needed intervention" and added: "It is clear that without this reintroduction work the future of the pine hoverfly would be bleak.

"Without action, one of Scotland's most vulnerable insects is in real danger of becoming extinct, something I am certain nobody wants to see.

"Losing any species can be disastrous for biodiversity and can also create subsequent negative long-term effects. However, while the pine hoverfly's demise is preventable, its loss would be unforgivable."

Johnnie Grant, the Rothiemurchus owner, said: "Enhancing biodiversity is part of good land management and helps to create the superb landscapes in which so many people enjoy being active."