Mysterious red beetles appeared in Goričko
Cinnabar flat bark beetle (Cucujus cinnaberinus) is a small beetle whose distribution in Slovenia and Goričko was nearly unknown until recently. The first large-scale survey in Slovenia showed that the cinnabar flat bark beetle is mainly distributed in lowland floodplain forests along river Mura, Drava and Sava. One of the reasons for the poor knowledge of the species distribution as well as its ecology, is its cryptic lifestyle as it spends most of the year hidden under the bark of dead trees.
It is only with the recent introduction of field survey method of detection of adult beetles and larvae under the bark of dead trees that knowledge of this endangered and important European species had improved. At the beginning of year 2020, beetle experts inventoried a selected forest areas in Čikečka vas, Vučja Gomila, Motvarjevci and Selo, as only one find was previously known from the area of Bukovnica. The inventory of the selected sites was successful. Adult beetles or their larvae were found in 8 out of 23 sites, mostly under the bark of dead trees of the black locust and common oak. Cinnabar flat bark beetle lives only under the bark of dead trees, where it preys on other small non-vertebrates or feeds on fungal hyphae.
In order to increase the amount of dead wood within the selected areas, we published a public appeal on our webstite at the end of year 2020. In this appeal, we invited forest owners in the cadastral zones of Čikečka vas, Selo, Vučja Gomila, Motvarjevci and Bukovnica to participate and establish habitat trees for the cinnabar flat bark beetle. Habitat trees are trees that are left to its natural development and thus become habitats for a variety of organisms, like saprophytic fungi, beetles, birds and bats.
In order to established suitable habitat trees for cinnabar flat bark beetle, the landowners that applied to public appeal will sign a nature conservation contract within the project Gorička Krajina. In accordance to its terms of agreement they will carried out girdling of selected trees. The trees were selected on their adequacy and marked with a special sign. All selected trees have a diameter from 35 to 70 cm. Girdling is a measure whereby the outer bark, cambium and the last few annual rings of wood are sawn, which weakens the tree and eventually causes the death of the tree.
The forest owners will receive a financial compensation of 90 EUR for the girdling of each tree. Number of trees was limited by individual landowner on maximum 15 in one or maximum 30 in two cadastral zones. The trees were selected by mutual agreement of landowner and our forester. Tree species, selected as suitable, were sessile or common oak, black locust, bird cherry, common aspen or black alder. After girdling, the trees will remain in the forest for at least 20 years. All 120 habitat trees are marked with a red beetle symbol.
