Skip to main content Skip to main navigation menu Skip to site footer
Responsive image
Issue: Vol. 5671 No. 1: 1 Aug. 2025
Type: Monograph
Published: 2025-08-01
DOI: 10.11646/zootaxa.5671.1.1
Page range: 1-74
Abstract views: 125
PDF downloaded: 4

Taxonomic Revision and Phylogeny of the Genus Peltocercyon d'Orchymont, 1925 (Coleoptera: Hydrophilidae: Megasternini)

Faculty of Environmental Sciences; Department of Ecology; Czech University of Life Sciences Prague; Czech Republic.; Life Sciences School; Sun Yat-sen University; Guangzhou; 510275; Guangdong; China.
Life Sciences School; Sun Yat-sen University; Guangzhou; 510275; Guangdong; China.
Baranavichy State University; 21 Voykova str.; Baranavichy; Brest Reg. 225404; Belarus.
Division of Life Sciences (Insects); The Natural History Museum; Cromwell Road; London SW7 5BD; U.K.
Natural History Division; Kitakyushu Museum of Natural History and Human History; 2-4-1 Higashida; Yahatahigashi-ku; Kitakyushu-shi; Fukuoka; 805-0071 Japan.
Department of Biological Sciences; National Sun Yat-sen University; No.70 Lien-hai Rd.; Kaohsiung City 80424.; Department of Entomology; National Museum; Cirkusová 1740; Praha – Horní Počernice; CZ-19300 Czech Republic.
Faculty of Environmental Sciences; Department of Ecology; Czech University of Life Sciences Prague; Czech Republic.
Coleoptera Hydrophilidae Sphaeridiinae Megasternini molecular systematics revision new species new combination new record Asia

Abstract

The Asian-endemic genus Peltocercyon d'Orchymont, 1925 (Coleoptera: Hydrophilidae: Sphaeridiinae: Megasternini) is revised and redefined based on morphological characters and DNA data (five nuclear and three mitochondrial fragments). The metaventrite, with complete femoral lines crossing the arcuate ridges, is confirmed as the best diagnostic character for Peltocercyon in contrast to the morphology of the prosternum and mesoventrite which vary within the genus. DNA data reveal that Peltocercyon contains two separate lineages and that aedeagal morphology is more phylogenetically informative than external characters. A total of 17 species are recognized, of which nine are newly described: Peltocercyon basirugosus sp. nov. (China: Hainan, Yunnan; Laos: Bolikhamsai, Phongsaly Luang Prabang), P. carnarius sp. nov. (Indonesia: West Sumatra; Philippines: Mindanao; Malaysia: Sabah, Sarawak), P. kouwenkaii sp. nov. (China: Xizang), P. latifossus sp. nov. (Indonesia: Sumba), P. maculipennis sp. nov. (China: Taiwan, Sichuan, Chongqing, Guizhou and Guangxi; Laos: Houaphanh; Vietnam: Tam Dao; India: Arunachal Pradesh), P. medogensis sp. nov. (China: Xizang), P. rugosipennis sp. nov. (China: Xizang), P. splendidus sp. nov. (China: Xizang, Yunnan, Sichuan, Shaanxi, Hubei; India: Arunachal Pradesh), P. taylorae sp. nov. (China: Yunnan; Laos: Houaphanh, Phongsaly; India: Arunachal Pradesh). Three species are transferred to Peltocercyon from Cercyon Leach, 1817: Peltocercyon vagus (Sharp, 1884), comb. nov., P. vividus (d'Orchymont, 1925), comb. nov., and P. sanaii (Hoshina, 2008), comb. nov. Peltocercyon coomani d'Orchymont, 1925 is newly recorded from China, Laos, Thailand and Malaysia, P. lunulatus (Gemminger & Harold, 1868) from China, Laos, Malaysia, Cambodia and Myanmar, and P. vividus for Malaysia, Thailand and Indonesia. The closely related species P. maculipennis sp. nov., P. medogensis sp. nov., P. splendidus sp. nov. and P. taylorae sp. nov. are treated as the P. splendidus group. The Japanese and Far East species P. vagus (Sharp, 1884), P. subopacipennis (Nakane, 1965), P. sanaii (Hoshina, 2008), P. shigehisai Hoshina, 2018 and P. ohoni Hoshina, 2021 are treated as the P. vagus group, both groups being based on elytral sculpture, aedeagal morphology and distribution. Members of the P. vagus group are not treated taxonomically in detail due to limited material available. Diagnostic characters of all species and species groups are illustrated by photographs and SEM micrographs and an identification key and distribution maps of all species are provided. All known Peltocercyon inhabit decaying organic material; we provide the first hypothesis on the evolution of their habitat preferences.

 

References

  1. Arriaga-Varela, E., Sýkora, V. & Fikáček, M. (2021) Molecular phylogeny of Megasternini terrestrial water scavenger beetles (Hydrophilidae) reveals repeated continental interchange during Paleocene-Eocene thermal maximum. Systematic Entomology, 46, 570–591. https://doi.org/10.1111/syen.12476
  2. d'Orchymont, A. (1925) Contribution à l'étude des Hydrophilides III. Bulletin et Annales de la Société entomologique de Belgique, 65, 261–295.
  3. Fikáček, M. (2009) Occurrence of introduced species of the genus Cercyon (Coleoptera: Hydrophilidae) in the Neotropical Region. Revista de la Sociedad Entomológica Argentina, 68 (3–4), 351–357.
  4. Fikáček, M., Jia, F. & Porkin, A. (2012) A review of the Asian species of the genus Pachysternum (Coleoptera: Hydrophilidae: Sphaeridiinae). Zootaxa, 3219 (1), 1–53. https://doi.org/10.11646/zootaxa.3219.1.1
  5. Gemminger, M. & Harold, B. de. (1868) Catalogus Coleopterorum hucusque descriptorum synonymicus et systematicus. Vol. 2. E. H. Gummi, Monachii, 425–752 + 6 (index, unnumbered) pp. https://doi.org/10.5962/bhl.title.9089
  6. Hansen, M. (1991) The hydrophiloid beetles. Phylogeny, classificationand a revision of the genera (Coleoptera, Hydrophiloidea). Biologiske Skrifter, 40, 1–368.
  7. Hansen, M. (1999) World Catalogue of Insects 2: Hydrophiloidea (Coleoptera). Apollo Books, Stenstrup, 416 pp. https://doi.org/10.1163/9789004629042_004
  8. Hoang, D.T., Chernomor, O., von Haeseler, A., Minh, B.Q. & Vinh, L.S. (2018) UFBoot2: Improving the Ultrafast Bootstrap Approximation. Molecular Biology and Evolution, 35 (2), 518–522. https://doi.org/10.1093/molbev/msx281
  9. Hoshina, H. (2008) A new species of the genus Cercyon (Coleoptera: Hydrophilidae) from Fukui Pref., Japan. Bulletin of the Center for Regional Environmental Research and Education, University of Fukui, "Nature and Environment of the Japan Sea Region", 15, 1–7.
  10. Hoshina, H. (2016) Taxonomic Report of the Genus Peltocercyon (Coleoptera: Hydrophilidae: Sphaeridiinae). Japanese Journal of Systematic Entomology, 22 (1), 131–133.
  11. Hoshina, H. (2018) Discovery of Second Japanese Species of the Genus Peltocercyon (Coleoptera: Hydrophilidae: Sphaeridiinae) with Description of a New Species. Japanese Journal of Systematic Entomology, 24 (2), 293–295.
  12. Hoshina, H. (2021) Taxonomic Report of the Genus Peltocercyon (Coleoptera: Hydrophilidae: Sphaeridiinae) (II). Japanese Journal of Systematic Entomology, 27 (2), 335–337.
  13. Kumar, S., Stecher, G. & Tamura, K. (2016) MEGA7: Molecular Evolutionary Genetics Analysis version 7.0 for bigger datasets. Molecular Biology and Evolution, 33 (7), 1870–1874. https://doi.org/10.1093/molbev/msw054
  14. Lanfear, R., Frandsen, P.B., Wright, A.M., Senfeld, T. & Calcott, B. (2017) PartitionFinder 2: New methods for selecting partitioned models of evolution for molecular and morphological phylogenetic analyses. Molecular Biology and Evolution, 34 (3), 772–773. https://doi.org/10.1093/molbev/msw260
  15. Lu, G. & Moriyama, E.N. (2004) Vector NTI, a balanced all-in-one sequence analysis suite. Briefings in Bioinformatics, 5 (4), 378–388. https://doi.org/10.1093/bib/5.4.378
  16. Mai, Z., Wang, L., Ryndevich, S.K., Fikáček, M., Arriaga-Varela, E. & Jia, F. (2024) DNA but not always morphology help to recognise monophyletic genera within ‘Cercyon’ terrestrial water scavenger beetles: a case study of Asiacyon gen. nov. (Coleoptera: Hydrophilidae). Invertebrate Systematics, 38, 1–71. https://doi.org/10.1071/IS24012
  17. Mannerheim, C.G. (1853) Dritter Nachtrag zur Kaefer-Fauna der Nord-Amerikanischen Laender des Russischen Reiches. Bulletin de la Société impériale des Naturalistes de Moscou, Series 2, 26 (3), 95–273.
  18. Miller, M.A., Pfeiffer, W. & Schwartz, T. (2010) Creating the CIPRES Science Gateway for inference of large phylogenetic trees. In: Proceedings of the Gateway Computing Environments Workshop (GCE). IEEE, Piscataway, New Jersey, pp. 1–8. https://doi.org/10.1109/GCE.2010.5676129
  19. Motschulsky, V. (1863) Essai d'un Catalogue des Insectes de l'Ile Ceylan. Bulletin de la Société impériale des Naturalistes de Moscou, Series 1, 36 (2), 421–532.
  20. Nguyen, L.T., Schmidt, H.A., von Haeseler, A. & Minh, B.Q. (2015) IQ-TREE: A fast and effective stochastic algorithm for estimating maximum-likelihood phylogenies. Molecular Biology and Evolution, 32 (1), 268–274. https://doi.org/10.1093/molbev/msu300
  21. Rambaut, A., Drummond, A.J., Xie, D., Baele, G. & Suchard, M.A. (2018) Posterior summarization in Bayesian phylogenetics using Tracer 1.7. Systematic Biology, 67 (5), 901–904. https://doi.org/10.1093/sysbio/syy032
  22. Ronquist, F., Teslenko, M., van der Mark, P., Ayres, D.L., Darling, A., Höhna, S., Larget, B., Liu, L., Suchard, M.A. & Huelsenbeck, J.P. (2012) MrBayes 3.2: Efficient Bayesian phylogenetic inference and model choice across a large model space. Systematic Biology, 61 (3), 539–542. https://doi.org/10.1093/sysbio/sys029
  23. Ryndevich, S.K. (2006) Review of species of genus Cercyon Leach, 1817 of Russia and adjacent regions. III. Subgenera Clinocercyon Orchymont, 1942 and Conocercyon Hebauer, 2003 (Coleoptera: Hydrophilidae). Zoosystematica Rossica, 15 (2), 315–320. https://doi.org/10.31610/zsr/2006.15.2.315
  24. Ryndevich, S.K. (2008) Review of species of the genus Cercyon Leach, 1817 of Russia and adjacent regions. IV. The subgenera Paracycreon Orchymont, 1924 and Dicytocercyon Ganglbauer, 1904 (Coleoptera: Hydrophilidae). Zoosystematica Rossica, 17 (2), 89–97. https://doi.org/10.31610/zsr/2008.17.2.89
  25. Ryndevich, S.K., Prokin, A.A., Makarov, K.V. & Sundukov, Yu.N. (2021) The beetles of the families Helophoridae, Georissidae, Hydrophilidae, Hydraenidae, and Elmidae (Insecta: Coleoptera) of Kunashir Island and the Lesser Kurils. Journal of Asia-Pacific Biodiversity, 14, 461–491. https://doi.org/10.1016/j.japb.2021.06.007
  26. Ryndevich, S.K. (2008) Review of species of the genus Cercyon Leach, 1817 of Russia and adjacent regions. IV. The subgenera Paracycreon Orchymont, 1924 and Dicytocercyon Ganglbauer, 1904 (Coleoptera: Hydrophilidae). Zoosystematica Rossica, 17 (2), 89–97. https://doi.org/10.31610/zsr/2008.17.2.89
  27. Vaidya, G., Lohman, D.J. & Meier, R. (2011) SequenceMatrix: concatenation software for the fast assembly of multi-gene datasets with character set and codon information. Cladistics, 27 (2), 171–180. https://doi.org/10.1111/j.1096-0031.2010.00329.x
  28. Girón, J.C. & Short, A.E.Z. (2021) The Acidocerinae (Coleoptera, Hydrophilidae): taxonomy, classification, and catalog of species. Zookeys, 1045, 1–236. https://doi.org/10.3897/zookeys.1045.63810

How to Cite

Mai, Z., Jia, F., Ryndevich, S.K., Angus, R., Minoshima, Y.N., Fikáček, M. & Růžička, J. (2025) Taxonomic Revision and Phylogeny of the Genus Peltocercyon d’Orchymont, 1925 (Coleoptera: Hydrophilidae: Megasternini). Zootaxa, 5671 (1), 1–74. https://doi.org/10.11646/zootaxa.5671.1.1