Beetle Blitz in the Caucasus: 66 Species Recorded in Georgia for the First Time

Deep in the forests of the Caucasus Mountains, a single season of trapping has rewritten the beetle inventory of an entire country. A survey of the Lagodekhi Protected Areas in northeastern Georgia has documented 195 species of beetles, the insect order Coleoptera, belonging to 42 families and 172 genera. Of these, 157 species had never been recorded in the protected area before, and 66 turned out to be entirely new records for Georgia as a nation. Three whole families of beetles, the Rhysodidae, Sphindidae and Thymalidae, were added to the country’s faunal list for the first time, alongside 30 families that were new to Lagodekhi itself. The findings, published in the journal Caucasiana, offer a striking reminder of how much biodiversity can remain undocumented even in a region that scientists have studied intensively for more than a century.

The Lagodekhi Protected Areas occupy the extreme northeastern corner of Georgia, on the southern slopes of the Caucasus Mountains, and span an altitudinal range from 590 to 3,500 meters above sea level. The complex combines the Lagodekhi Natural Reserve, established in 1912 largely through the efforts of the Polish forester and naturalist Ludwik Młokosiewicz, with an adjoining Managed Reserve, covering a total of roughly 24,000 hectares. The reserve protects one of the world’s best-preserved primeval deciduous forest habitats, a mosaic of lowland and montane forests, subalpine meadows and alpine zones that supports an extraordinary range of insect life. Because of this habitat diversity and a long history of entomological work, Lagodekhi is considered the best-studied protected area for insect diversity anywhere in the Caucasus region.

That reputation, however, rested on inventories that were far from complete. The first summary of the reserve’s insect diversity, published in 1956, listed 632 insect taxa. More recent updates had brought the total to about 1,790 species records, yet researchers suspected that the true number was vastly higher. The suspicion proved well founded: when material collected in 2014 was analyzed for parasitoid wasps of the family Ichneumonidae, the study yielded 313 new records for Lagodekhi, including 209 new country records. A parallel analysis of leaf beetles from the same material reported 48 species with 14 new country records. The new beetle survey, drawing on the same trapping program and supplemented by collections from recent years, extends that pattern dramatically across the order Coleoptera, one of the most species-rich groups of insects on Earth.

The technical backbone of the study was a network of malaise traps, tent-like interception devices that passively capture flying insects, operated at six sites spanning the full elevational gradient of the protected area. The lowest site stood in low-altitude forest at 666 meters, followed by mid-altitude forest at 847 meters, high-altitude forest at 1,351 meters dominated by Oriental beech, subalpine forest at 1,841 meters, subalpine meadow and scrubland at 2,230 meters, and finally the alpine zone at 2,559 meters. Traps at the four lower sites ran through the entire growing season from April to November 2014, while the two highest sites were sampled from May to early October because of harsher climatic conditions. Samples were collected roughly every ten days and preserved in 96 percent ethanol before sorting.

The malaise trap program was supplemented by two other standardized methods. Twelve-funnel traps, which intercept insects crawling and flying along tree trunks and stems, operated from early May to early August 2014, while Moericke traps, bright yellow pan traps that exploit the attraction of many insects to the color yellow, ran from early May to mid-June. These devices were installed at the same localities as the malaise traps, allowing direct comparison across habitats and elevations. The team also incorporated occasional hand collection carried out during field campaigns over the preceding decade, including nocturnal searches on dead beech snags, where several wood-associated species were found. Each record in the resulting species list documents the number of specimens, the sampling locality, the date, the collection method and the collectors, providing a verifiable voucher-backed baseline for future work.

Identifying the hundreds of captured specimens required international collaboration. Specialists from Poland and elsewhere examined particular families, including the hister beetles, ptinid beetles, minute brown scavenger beetles, sap-feeding beetles, rove beetles, jewel beetles, fungus beetles, weevils and click beetles, while the authors identified the remaining material. New records for the protected area and new country records were verified primarily against the multi-volume Catalogue of Palaearctic Coleoptera, the authoritative reference for beetle distributions across Europe, Asia and North Africa. The authors applied a deliberately conservative standard: where they could not locate an original source confirming a species’ presence in Georgia, and where no later confirmation existed, they excluded the record rather than risk inflating the country list. Voucher specimens are retained in the authors’ collections, and nomenclature was cross-checked against the Global Biodiversity Information Facility.

The results reveal a beetle fauna dominated by species tied to old-growth forest, dead wood and fungi, reflecting the primeval character of Lagodekhi’s habitats. Among the longhorn beetles alone, the survey added dozens of records, including species whose larvae develop in decaying timber, such as the large and distinctive Rhaesus serricollis, whose emergence holes were observed in decomposed beech snags. Iconic saproxylic beetles also appeared in the catches, among them the European stag beetle Lucanus cervus and its relative Lucanus ibericus ibericus, as well as the striking violet longhorn Rosalia alpina, a flagship species for the conservation of dead-wood habitats. Fungus-associated families flourished in the trap material: the pleasing fungus beetles of the family Erotylidae, the hairy fungus beetles, the minute tree-fungus beetles of the family Ciidae and the handsome fungus beetles all contributed new records, and a single nocturnal search on a bracket fungus produced 65 specimens of the pleasing fungus beetle Diaperis boleti.

Equally notable are the bark beetles and ambrosia beetles of the weevil subfamilies captured in the traps. Species such as Platypus cylindrus, the pinhole borer, appeared in large numbers across multiple sites and months, while others, including Xyleborinus saxesenii, Xylechinus pilosus and Anisandrus dispar, were recorded in Georgia for the first time. These tiny beetles bore into wood and, in the case of ambrosia beetles, cultivate fungal gardens inside their tunnels, playing crucial roles in the decomposition and nutrient cycling of forest ecosystems. Their detection in a primeval beech forest underscores how poorly known even ecologically pivotal groups remain in the South Caucasus, and how passive trapping methods can expose hidden components of the fauna that hand collection routinely misses.

The three families newly recorded for Georgia illustrate the global significance of the finding. Rhysodidae, represented in the survey by Omoglymmius germari, is a small family of slender, reddish predators that live in the galleries of fungi-infested wood. Sphindidae, with two Aspidiphorus species caught in the traps, comprises minute beetles that feed on slime molds. Thymalidae, documented through a single specimen of Thymalus aubei collected by hand, was previously unrecorded in the country altogether. Each of these records was flagged with the study’s double-asterisk convention for new country records, and each depends on the physical voucher specimen as its ultimate proof. In an era when distributional claims can circulate without evidence, the authors’ insistence on documented, verifiable specimens gives the new Georgian checklist a firm foundation.

The authors emphasize that their 195 species represent only a snapshot of the beetle diversity of Lagodekhi, gathered from a single intensive season and a handful of supplementary campaigns. Given the high landscape and habitat diversity of both the national park and Georgia as a whole, they expect future research to yield many more species new to the area and to the country. The study also carries a broader message for biodiversity science: even in regions with a century of entomological history, standardized, sustained and elevation-stratified sampling can still transform a national species list within a single year. For conservationists, the wealth of dead-wood-dependent beetles documented at Lagodekhi provides fresh evidence that protecting primeval forest habitats, as this reserve has done since 1912, preserves ecological communities that exist nowhere else in such intact form.

Subject of Research: Beetle diversity and new faunal records in the Lagodekhi Protected Areas, Georgia

Article Title: New records of Coleoptera from Lagodekhi Protected Areas, with new records for Georgia (Sakartvelo)

Article References: Japoshvili, G., Hilszczański, J., Byk, A., Jaworski, T., Łoś, K., Borowski, J., Tarwacki, G., Piętka, J., & Plewa, R. (2022). New records of Coleoptera from Lagodekhi Protected Areas, with new records for Georgia (Sakartvelo). Caucasiana, 1, 29-39. https://doi.org/10.3897/caucasiana.1.e85239

Image Credits: AI Generated

DOI: 10.3897/caucasiana.1.e85239

Keywords: Coleoptera, beetles, Lagodekhi Protected Areas, Georgia, biodiversity, new country records, Caucasus, malaise traps, saproxylic beetles, entomology, species inventory, forest conservation