The very rare shining beetle Glischrochilus tremulae has been found in SCA's biodiversity park Tjäderberget outside Lycksele, marking the first recorded discovery in Västerbotten.

The species has strict habitat requirements and a clear dependence on sun-exposed hollow aspens.

Roger Mugerwa Pettersson, a conservation biologist specializing in ecological communities of insects and arachnids in boreal forests, has carried out several species inventories for SCA in the Tjäderberget biodiversity park. The park is one of SCA's five parks in northern Sweden where research is combined with the company's efforts to develop nature conservation and forestry methods from a landscape perspective.

"We have these parks, among other reasons, to develop working methods that promote specific structures such as old trees, dead wood, deciduous forests, burned areas, wetlands, and other natural features that are valuable for rare species. This kind of finding is a welcome confirmation that the continuous work in the biodiversity parks is yielding results," says Ola Kårén, Chief Forester.

The find of Glischrochilus tremulae consisted of five individuals. They were caught in traps placed on a couple of large hollow aspens in an aspen-rich area of Tjäderberget.
The beetles were originally collected back in 2015 and were initially identified as a more common species. When another insect researcher later identified collected beetle samples, he contacted Roger Mugerwa Pettersson, who re-examined the specimens.

"I dug out my beetles and realized they were probably the rare species. I have also had my identification confirmed by Finnish researcher Tom Clayhills, one of the three scientists who first described the species in 2016," says Roger Mugerwa Pettersson.

Knowledge about Glischrochilus tremulae is still very limited. The findings on SCA land in Tjäderberget are the oldest in Sweden. Beyond that, there are only a few other registered findings from recent years, including one from Vindeln in 2022. All Swedish findings so far come from well-known deciduous-rich areas with plenty of aspen.

"It is very picky about its habitat and prefers deciduous forests dominated by aspen. It lives in old hollow aspens--trees that have become hollow through rot. This is a relatively uncommon but important habitat for many insects and birds," says Roger Mugerwa Pettersson.

To support the beetle's continued presence in Tjäderberget's biodiversity park, SCA is considering possible measures to promote the local habitats the species depends on.

"For other tree species, such as pine, we work with what is called veteranization. You damage the tree by scraping off bark, and over time it develops characteristics that benefit certain species. Perhaps it is possible to get aspens to develop heart rot more quickly by damaging the bark or inoculating the fungus. This would be interesting to test in Tjäderberget now that we know the species is present. The most important contribution to this species, however, is that we leave aspen as retention trees during harvesting. These become sun-exposed, and older aspens are often rotten and hollow," says Ola Kårén.