On the island of Abruka off the southern coast of Saaremaa, Estonian naturalists discovered a hermit beetle specimen. This scenic island has an ancient, lush and diverse broadleaf forest with ferns that are taller than a human being. According to Triin Reitalu, a restoration ecology researcher at the University of Tartu, the discovery will cast light on how to better preserve old forests.
This summer, as part of the WoodmeadowLife project, we searched for the hermit beetle (Osmoderma barnabita, an internationally protected species living in the hollows of old deciduous trees and considered a relic of primeval forests – ed.) in Estonian meadows and oak woods.
The presence of the beetle can be verified by using pheromone probes that mimic the pheromone secreted by the male hermit beetle. We used the help of local biologists in different parts of Estonia to set and check the traps.
Gerta Nurk, a biology teacher from Saaremaa, discovered a specimen in Abruka end of July this year. The most recent records in Estonia are from the wooded meadows along the Koiva River in southern Estonia, where the population of the hermit beetle is related to the Latvian population on the same river.
Hermit beetles could be found in old, sun-exposed deciduous woods, wooded meadows and parks. Beetle larvae develop in the cavities of old living oaks with semi-mature wood, but occasionally also in other hardwoods.
The hermit beetle is a large blackish-brown beetle with bronze scales. Male hermit beetles secrete a distinctive pheromone scent that can even be caught by the human nose: it is reminiscent of the smell of leather, plum or apricot. It is one of the largest beetles in Estonia and its larvae can grow up to three to four centimeters long.
The hermit beetle in Estonia falls under protection category II. IIt is also protected across Europe, having been included in Annex II and IV of the EU Habitats Directive. Estonia's hermit beetle habitats, semi-open stands of old broadleaved trees or wooded meadows and wood pastures, have been formed in Estonia by centuries of moderate mowing and grazing.
If the stand becomes scrubby when management ceases, the habitats for hermit beetles and many other insects, fungi, plants and birds characteristic of semi-open broadleaved stands will disappear. Our ongoing WoodmeadowLife project focuses on the restoration of wooded meadows in order to conserve these characteristic Estonian heritage sights.
Editor: Airika Harrik, Kristina Kersa