Published in the scientific journal Insect Systematics and Diversity, the study is the first comprehensive review of the beetle genus in China. The researchers documented more than 100 species, over half of which are newly discovered.
Even Large Species Can Go Undiscovered
What makes the discovery particularly remarkable is that these are not tiny or elusive organisms that are easily overlooked. Platydracus beetles are relatively large, often several centimetres long, and many are colourful or mimic wasps. Yet numerous species have remained unnoticed in the wild or unidentified in museum collections for decades.
– It is remarkable that so many new species can remain hidden among large and colourful beetles. It shows how little we actually know about biodiversity, and that even highly visible species can still go unnoticed, says Alexey Solodovnikov, Associate Professor and Curator at the Natural History Museum Denmark.
Solodovnikov is the lead author of the study, which was led by his PhD student Qinghao Zhao together with postdoctoral researcher Aslak Kappel Hansen. The study was carried out in collaboration with researchers from the Ottawa Research and Development Centre and Shanghai Normal University.
Read the research article, ‘Integrative taxonomic revision of the rove beetle genus Platydracus of the Chinese fauna (Coleoptera, Staphylinidae, Staphylininae)’, in Insect Systematics and Diversity.
Their study highlights a well-known problem in biodiversity research: the so-called Linnean shortfall – a term describing the enormous gap between the number of species that have been formally named and described and the actual number of species in the world. Within the rove beetle family (Staphylinidae), to which Platydracus belongs, around 70,000 species are known worldwide. However, researchers estimate that the species currently known represent only 20–25% of the total number of rove beetle species that actually exist in the wild.
Insects as a whole are the most species-rich group of animals on Earth. Scientists have described around 925,000 insect species, but estimates suggest that the total number could exceed five million.
Old Descriptions and New Methods
The study also shows that even previously described species are often insufficiently documented. Many species have been known only from a single or a handful of older specimens, leaving limited knowledge of their distribution, variation and ecology.
The researchers have therefore not only described new species but, in several cases, also corrected previous errors where species had been misidentified or described on the basis of evidence that is insufficient by modern taxonomic standards.
– Many species were originally described on a very limited basis. With more specimens and modern methods of investigation, we can now test and refine previous species boundaries while adding new species to the mosaic of life. This gives us a much more accurate picture of biodiversity, which is essential both for our understanding of nature and our ability to protect it, explains Alexey Solodovnikov.
The researchers combined traditional morphological analyses with DNA barcoding and found that species can sometimes vary considerably in appearance despite sharing the same DNA markers – or vice versa. This points to the need for more integrative approaches in future biodiversity research and for the re-examination of ‘known’ species as their newly discovered relatives come to light.
A Foundation for Future Biodiversity Research
The study provides an important foundation for future research on Platydracus in China and across Southeast Asia – vast regions that contain some of the world’s most important biodiversity hotspots. At the same time, it highlights just how limited our knowledge remains, even when it comes to relatively large and easily recognisable species.
Even for many named species, their distribution, behaviour and ecology remain largely unknown. In this study, several species are known from only a few specimens collected at individual localities.
The task of documenting biodiversity is therefore far from complete. On the contrary, the study demonstrates that even well-studied groups continue to contain large numbers of unknown species – and that the work of describing and understanding them is essential for both scientific research and nature conservation in the future.
Alexey Solodovnikov
Curator and Head of Zoology Research, Natural History Museum Denmark
Mail: asolodovnikov@snm.ku.dk
