Giant Centipede’s Secret Austrian Refuges Reveal Two Separate Post-Ice Age Colonization Routes

The giant centipede Scolopendra cingulata, one of Europe’s largest and most recognizable myriapods, is famous for its striking color variation and infamous for its painful bite. Widely distributed around the Mediterranean Sea, the species reaches its northern distributional limit in a handful of tiny, isolated populations in Romania, Hungary and Austria. These outposts have long puzzled zoologists: how did a warmth-loving Mediterranean animal come to survive in Central Europe, and where did these populations come from? A new study published in the journal Evolutionary Systematics now provides the clearest answer yet, revealing that the northern-most populations are relicts of multiple, independent post-glacial colonization events from separate southern refugia.

Relict populations like these are of outsized importance for conservation biology. When climate change or other catastrophic events shrink the range of a widespread species, small refugia can shield remnant populations from extinction. Such pockets often harbor unique genetic information that has been lost elsewhere in the species’ range, and they can serve as sources for future recolonization. For S. cingulata, the northern populations are small in numbers of individuals, occupy only very limited areas, and are considered locally endangered, particularly because of habitat alteration. Understanding their origins is therefore not just an academic exercise but a prerequisite for protecting them.

The new work builds on a discovery that made headlines among Central European naturalists several years ago. The first Austrian population of the giant centipede, in Burgenland near the Hungarian border, was rediscovered and subjected to molecular analysis, which showed that the isolated populations in Romania, Hungary and Austria likely have independent origins. However, that earlier study could not propose a clear hypothesis about where the Austrian animals specifically had come from. Because Austria, despite its small size, has a very large and active community of naturalists and zoologists, the researchers hoped that publishing their initial findings would prompt reports of additional populations of this conspicuous large invertebrate.

That hope was realized. Professor E. Christian of the University of Natural Resources and Life Sciences in Vienna reported a second locality, just five kilometers from the previously described population. The site was visited in 2015 in the company of Dr. Andreas Ranner of the nature and environmental protection office of the Burgenland provincial government, and the presence of the giant centipede was confirmed. Two juvenile specimens were collected under permit and deposited as vouchers at the Zoological Research Museum A. Koenig in Bonn, where their DNA barcodes could be sequenced. Notably, the exact localities of the Austrian populations are not disclosed in the publication, because wild-caught specimens of this long-lived, charismatic invertebrate are commonly offered for sale in the pet trade, and private collectors could severely deplete the small populations.

The second Austrian population lives on an exposed south-facing slope with scattered rocks and shrubs, the same kind of warm microhabitat as the first population. Adults are amber colored with yellow legs and a dark longitudinal dorsal stripe, while juveniles are greyish-blue with an orange head and last tergite, blue legs and a black dorsal stripe. The coloration matches what was described for the first Austrian population. Genetically, however, the two newly sequenced juveniles carried two different haplotypes of the mitochondrial COI gene, differing at 11 positions, or 1.7 percent of the sequence. One haplotype was identical to some found in the first Austrian population, while the second differed from the first population by up to 3.0 percent, immediately signaling that the genetic diversity within Austria was greater than previously appreciated.

To place these new sequences in context, the team assembled a dataset of 31 COI sequences: 29 of S. cingulata from 16 populations spanning France, Croatia, Austria, Hungary, Romania, Greece and Turkey, plus two sequences of the related species Scolopendra canidens as an outgroup. The sequences were aligned with the MUSCLE algorithm, and genetic distances were computed in MEGA X using uncorrected pairwise distances across all codon positions. Phylogenetic relationships were reconstructed under the maximum likelihood criterion in IQ-TREE, with the best-fitting substitution model selected by the Bayesian information criterion and branch support estimated from 1,000 bootstrap replicates. The result was a robust framework for testing competing scenarios about the history of the northern populations.

The phylogenetic analysis delivered a striking result. The Croatian specimen and one haplotype from the second Austrian population fall together with the first Austrian population into a single well-supported clade, and the second, more divergent Austrian haplotype sits at the base of that same Croatian-Austrian group. In other words, the Austrian centipedes are not an isolated oddity but are closely related to the population on the Istrian coast of Croatia, from which they differ by only about 2.0 percent on average. By contrast, the genetic distances to the more eastern populations are much larger: 6.0 percent to Romania and 7.6 percent to Hungary. The Hungarian and Romanian specimens, together with Greek mainland populations and specimens from the Greek islands Koufonisi and Paros, form a separate clade, although that grouping received weaker statistical support.

These patterns point to a clear biogeographic conclusion. The close relationship between the Austrian and Croatian centipedes indicates that the northern-most populations of the species were colonized independently, possibly from separate refugia, after the last glacial period. At least two separate recolonization routes must be hypothesized: one from the west, via Croatia into Austria, and one from the east, via Greece or the Balkans into Hungary and Romania. This dual-route scenario agrees with what has been suggested for multiple groups of insects in the region. The earlier idea proposed by Attems in 1930, that the northern populations arose by gradual speciation along a distance gradient, cannot explain the observed distribution and relationships. The authors caution, however, that denser geographic sampling and population genetic markers with higher resolution will be needed to fully unravel the phylogeographic history of the species in the region.

The study also underscores how much unique genetic information these tiny refugia can contain. Within the first rediscovered Austrian population, genetic distances were low, yet the population carried a haplotype unique within the species. The second locality expands the known Austrian diversity considerably, highlighting the importance of small and fragile populations for the overall genetic diversity of a species. Across the full dataset, the maximum intraspecific genetic distance, 11.9 percent between an Austrian and a French specimen, is consistent with earlier findings of average distances of about 11 percent between clades of S. cingulata in southern Italy, suggesting substantial deep divergence across the species’ Mediterranean range.

Conservation implications follow directly from the genetics. Although no attempts have been made to formally quantify and monitor the Austrian populations, yearly excursion reports by the research team offer worrying hints. Large numbers of adults and sub-adults were observed in 2015 and 2016, but the 2017 report documented an unexpected rarity of the species, and a site visit in 2018 found only juveniles. The populations may therefore be small and subject to fluctuations in size. Given the unique genetic information they harbor, their habitats should be treated as important targets for protection. That argument is reinforced by the company the centipedes keep: the first Austrian population shares its habitat with the only known Austrian population of the centipede Cryptops croaticus and with the endangered ground beetle Carabus hungaricus. Protecting these warm south-facing slopes safeguards not just one charismatic giant centipede but an entire assemblage of thermophilic species clinging to the northern edge of their ranges, living remnants of a post-glacial world whose stories are only now being read from their DNA.

Subject of Research: Phylogeography and post-glacial origins of the northern microrefugial populations of the giant centipede Scolopendra cingulata

Article Title: Origins of the northern microrefugial populations of the giant centipede Scolopendra cingulata Latreille, 1829 revealed ( Chilopoda , Scolopendromorpha , Scolopendridae )

Article References: Oeyen, J. P., Moritz, L., & Wesener, T. (2026). Origins of the northern microrefugial populations of the giant centipede Scolopendra cingulata Latreille, 1829 revealed (Chilopoda, Scolopendromorpha, Scolopendridae). Evolutionary Systematics, 10(2), 275-281. https://doi.org/10.3897/evolsyst.10.205134

Image Credits: AI Generated

DOI: 10.3897/evolsyst.10.205134

Keywords: Scolopendra cingulata, giant centipede, microrefugia, phylogeography, COI barcoding, post-glacial recolonization, Austria, Croatia, Hungary, relict populations, conservation, Evolutionary Systematics