Save the beetles! Cut down trees!

This is a rufous-shouldered longhorn beetle (Anaglyptus mysticus), which, like many other wood-living beetles that live in southern Sweden, is at risk of extinction.

Ironically, one of the prime causes of the endangered status, researchers have discovered, is twentieth century legislation designed to protect and enrich the forest in which they live.

Researchers led by Oskar Gran, of the country’s Department of Biological and Environmental Sciences, discovered that the protective legislation – considered enlightened and world-leading at the time – served to lock off large tracts of forest, which grew denser and darker as crowded trees grew and prospered.

The beetles, unfortunately, are adapted to living in oak trees in sunlit and open woodland, so as their habitat became ever more packed, their risk of extinction grew.

The solution, Gran and colleagues reveal in a paper published in the journal Biodiversity and Conservation, was to cut down a lot of the trees.

“These insects represent a large part of the biodiversity that we have committed ourselves to preserving by law and through international agreements,” says Gran. 

“In addition to being beautiful and fascinating, they also play an important role in stabilising forest ecosystems.

“We previously knew that they responded positively to the thinning immediately after the management intervention. But the new study showed that the effect has continued and even been strengthened after 10 years.”