A “Balrog” in the Tunnels: Scientists discover a new cave cricket species on the tiny island of Kastellorizo, Greece

This previously unknown species of cave cricket was found thriving within a network of man-made tunnels.

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 Despite the intensity of modern exploration, the eastern Mediterranean continues to yield unexpected discoveries. On the small Greek island of Kastellorizo, researchers have documented a previously unknown cave cricket thriving within a network of man-made tunnels.

The species, named Dolichopoda balrogi, was described by researchers from Greece and published in the open-access Journal of Orthoptera Research. This discovery highlights how even small and seemingly ordinary habitats can shelter unique and previously unknown life.

A mysterious cricket in underground tunnels

The new species belongs to the genus Dolichopoda, a group of cave crickets that inhabit dark, humid environments such as caves, crevices, and underground spaces across southern Europe and the eastern Mediterranean. These insects are well known to evolutionary biologists because their isolated populations often evolve into distinct species on islands or in separate cave systems.

On the easternmost Greek island of Kastellorizo, researchers surveyed an artificial tunnel that serves as the island’s sole accessible land cave. To their surprise, they encountered a population of cave crickets bearing characteristics of the cave-dwelling genus Dolichopoda.

Detailed morphological and molecular study confirmed that the specimens represented a species new to science.

Artificial tunnel of Kastellorizo. Photo credit: Konstantinos Kalaentzis.

Why “balrogi”?

The species name balrogi was inspired by the Balrog, a legendary fire-demon from J.R.R. Tolkien’s The Lord of the Rings. In Tolkien’s story, the Balrog is an ancient creature hidden deep beneath the mountains, emerging from darkness. Its discovery is a fitting parallel; the cricket’s preference for deep, dark tunnel systems kept it outside the known record for decades.

The name also alludes to the circumstances of discovery of the species, which was found exclusively in a man-made tunnel. In Tolkien’s narrative, the Balrog is revealed only after the Dwarves “delved too deep”; similarly, Dolichopoda balrogi was discovered on Kastellorizo due to anthropogenic excavation on Mount Vigla, as the island lacks accessible caves. The epithet thus symbolically links deep excavation with the revelation of hidden subterranean fauna.

Dolichopoda balrogi sp. nov. Image credit: Konstantinos Kalaentzis.

Fortunately, unlike Tolkien’s fearsome creature, Dolichopoda balrogi is harmless – although equally well adapted to life in darkness.

Hidden biodiversity in unexpected places

Kastellorizo is a very small island, covering only about 9 square kilometers. Yet its position in the eastern Mediterranean between Asia and Europe makes it an important biogeographic hotspot.

Geographic distribution of Eastern Mediterranean Dolichopoda species. Image credit: © Environmental Systems Research Institute, Inc., CC BY 3.0.

The discovery of D. balrogi demonstrates that even small islands can host unique endemic species. It also suggests that artificial underground environments, such as tunnels and abandoned infrastructure, can function as refuges for specialised cave-dwelling organisms.

“These findings remind us that biodiversity discoveries are not limited to remote tropical forests or deep oceans. Even familiar landscapes and human-made structures can harbour species that have remained unnoticed.”

Konstantinos Kalaentzis

Protecting small and fragile ecosystems

Cave-adapted organisms like Dolichopoda crickets often have very restricted distributions, sometimes occurring in only a single cave or underground system. Because of this, they can be particularly vulnerable to habitat disturbance. The authors suggest that documenting and understanding these hidden species is an important first step toward their conservation.

Bayesian inference phylogenetic tree based on mitochondrial COI sequences of Dolichopoda species. Image credit: Konstantinos Kalaentzis.

As research continues across the Mediterranean, the researchers note that the countless Greek islands – many still poorly explored biologically – are likely to hold many more hidden biodiversity treasures awaiting discovery.

Cover image:

Newly discovered Dolichopoda balrogi sp. nov. in the artificial tunnel of Kastellorizo on 17 October 2025 – Female individual. Photo credit: Konstantinos Kalaentzis.

Original source:

Kalaentzis K, Alexiou S, Christopoulos A, Minoudi S, Koutsogiannopoulos D, Kotselis C, Triantafyllidis A (2026) Delving too deep: Morphological and molecular description of the cave-dwelling Dolichopoda balrogi sp. nov. (Orthoptera, Rhaphidophoridae) from Kastellorizo Island, Greece. Journal of Orthoptera Research 35(2): 259-266. https://doi.org/10.3897/jor.35.187943

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