Phylogenetic position of genera Acrostilicus Hubbard and Pachystilicus Casey (Staphylinidae, Paederinae) and their redescription

  • Dagmara Żyła Museum and Institute of Zoology, Polish Academy of Sciences, Wilcza 64, 00-679 Warsaw, Poland
  • Alexandra Tokareva Museum and Institute of Zoology, Polish Academy of Sciences, Wilcza 64, 00-679 Warsaw, Poland
  • Katarzyna Koszela Museum and Institute of Zoology, Polish Academy of Sciences, Wilcza 64, 00-679 Warsaw, Poland
Keywords: beetles, morphology, systematics, taxonomy, phylogeny, total-evidence analysis


Acrostilicus Hubbard, 1896 and Pachystilicus Casey, 1905 are North American genera known from only one and two species, respectively, and have never been a subject of a modern revision. In fact, Acrostilicus was not even properly described as its author provided only a sketchy diagnosis of the genus and species. Here, we provide a redescription of the genus Acrostilicus and its species and illustrate the habitus and male genital features. For the first time, we also redescribe Pachystilicus and its two species, and provide their differential diagnoses. Additionally, we tested the phylogenetic position of both genera. They were scored into a morphological matrix supplemented with molecular data and the analyses were run using Bayesian inference and maximum likelihood methods. A total of 119 morphological characters and 4859 bp of nuclear (28S, TP, Wg, CADA, CADC, ArgK) and mitochondrial (COI) sequences were analysed for 46 taxa. The results confirmed that both Acrostilicus and Pachystilicus are members of the subtribe Stilicina, but at the same time challenged the monophyly of the subtribe in its current composition. Additionally, we provided further evidence for non-monophyly of the subtribe Medonina and discussed the biology of Acrostilicus and Pachystilicus.


Assing V. 2011. A revision of Panscopaeus (Coleoptera: Staphylinidae: Paederinae). Contributions to Entomology 61 (2): 389–411.

Blackwelder R.E. 1939. A generic revision of the staphylinid beetles of the tribe Paederini. Proceedings of the United States National Museum 87 (3069): 93–125.

Blackwelder R.E. 1952. Generic names of the family Staphylinidae. Bulletin of the United States National Museum 200: 1–483.

Bogri A., Solodovnikov A., Kypke J.L. & Żyła D. 2020. Baltic amber members of the extant Micrillus-Scymbalium lineage of the Paederinae rove beetles (Coleoptera, Staphylinidae) and their systematic and ecological significance. Invertebrate Systematics 34 (5): 451–473.

Bouchard P., Bousquet Y., Davies A.E., Alonso-Zarazaga M.A., Lawrence J.F., Lyal C.H., Newton A.F., Reid C.A., Schmitt M., Ślipiński S.A. & Smith A.B. 2011. Family-group names in Coleoptera (Insecta). ZooKeys 88: 1–972.

Bousquet Y., Bouchard P., Davies A.E. & Sikes D.S. 2013. Checklist of beetles (Coleoptera) of Canada and Alaska. Second edition. ZooKeys 360: 1–44.

Brunke A.J. & Buffam J. 2018. A review of Nearctic rove beetles (Staphylinidae) specialized on the burrows and nests of Vertebrates. In: Biology of Rove Beetles (Staphylinidae). Life History, Evolution, Ecology and Distribution: 145–159. Springer, Cham.

Brunke A.J. & Schnepp K. 2021. Taxonomic changes in Nearctic Paederinae, new records and a redescription of enigmatic genus Acrostilicus Hubbard (Coleoptera: Staphylinidae). Coleopterists Bulletin 75 (4): 883–894.

Casey T.L. 1905. A revision of the American Paederini. Transactions of the Academy of Science of Saint Louis 15 (2): 17–248.

Fall H.C. 1901. List of the Coleoptera of southern California, with notes on habits and distribution and descriptions of new species. Occasional Papers of the California Academy of Sciences 8: 1–282.

Fall H.C. & Cockerell T.D.A. 1907. The Coleoptera of New Mexico. Transactions of the American Entomological Society 33: 145–272. Available from [accessed 11 Apr. 2022].

Frania H.E. 1986. Status of Eustilicus Sharp, Trochoderus Sharp, Deroderus Sharp, and Stilocharis Sharp (Coleoptera: Staphylinidae: Paederinae: Paederini) with implications for classification of the Medonina and Stilicina. Canadian Journal of Zoology 64 (2): 467–480.

Hoang D.T., Chernomor O., Haeseler A., Minh B.Q. & Vinh L.S. 2018. UFBoot2: Improving the ultrafast bootstrap approximation. Molecular Biology and Evolution 35: 518–522.

Hubbard H.G. 1896. Additional notes on the insect guests of the Florida land tortoise. Proceedings of the Entomological Society of Washington 3: 299–302.

Jackson D.R. & Milstrey E.G. 1989. The fauna of gopher tortoise burrows. In: Diemer J.E., Jackson D.R., Landers J.L., Layne J.N. & Wood D.A. (eds) Proceedings of the Gopher Tortoise Relocation Symposium. Nongame Wildlife Program Technical Report No. 5: 86–98. Florida Game and FreshWater Fish Commission, Gainesville, FL, USA.

Jones J.C. & Dorr B.S. 2004. Habitat associations of gopher tortoise burrows on industrial timberlands. USDA National Wildlife Research Center – Staff Publications 502. Available from [accessed 11 Apr. 2022].

Katoh K., Misawa K., Kuma K.I. & Miyata T. 2002. MAFFT: a novel method for rapid multiple sequence alignment based on fast Fourier transform. Nucleic Acids Research 30 (14): 3059–3066.

Lanfear R., Calcott B., Ho S. & Guindon S. 2012. PartitionFinder: combined selection of partitioning schemes and substitution models for phylogenetic analyses. Molecular Biology and Evolution 29 (6): 1695–1701.

Lanfear R., Frandsen P.B., Wright A.M., Senfeld T. & Calcott B. 2016. PartitionFinder 2: new methods for selecting partitioned models of evolution for molecular and morphological phylogenetic analyses. Molecular Biology and Evolution 34 (3): 772–773.

LeConte J.L. 1880. Short studies of North American Coleoptera. Transactions of the American Entomological Society and Proceedings of the Entomological Section of the Academy of Natural Sciences 8 (3): 163–218.

Leng C.W. 1920. Catalogue of the Coleoptera of America, North of Mexico. The Cosmos Press, Cambridge, MA, USA.

Lewis P.O. 2001. A likelihood approach to estimating phylogeny from discrete morphological character data. Systematic Biology 50 (6): 913–925.

Lin C.P. & Danforth B.N. 2004. How do insect nuclear and mitochondrial gene substitution patterns differ? Insights from Bayesian analyses of combined datasets. Molecular Phylogenetics and Evolution 30 (3): 686–702.

Lucas R. 1920. Catalogus alphabeticus generum et subgenerum Coleopterorum orbis terrarum totius (famil., trib., subtr., sect. incl.). V. 1. Nicolaische, Berlin.

Maddison W.P. & Maddison D.R. 2018. Mesquite: a modular system for evolutionary analysis. Version 3.61. Available from [accessed 11 Apr. 2022].

Miller M.A., Pfeiffer W. & Schwartz T. 2010. Creating the CIPRES Science Gateway for inference of large phylogenetic trees. Proceedings of the 2011 TeraGrid Conference: Extreme Digital Discover 41: 1–8.

Minh B.Q., Schmidt H.A., Chernomor O., Schrempf D., Woodhams M.D., Haeseler A. & Lanfear R. 2020. IQ-TREE 2: New models and efficient methods for phylogenetic inference in the genomic era. Molecular Biology and Evolution 37 (5): 1530–1534.

Moore I. & Legner E.F. 1979. An Illustrated Guide to the Genera of the Staphylinidae of America North of Mexico exclusive of the Aleocharinae (Coleoptera). Division of Agricultural Sciences, California University. Available from [accessed 11 Apr. 2022].

Newton A. 2018. Staphyliniformia world catalog database. In: Bánki O., Roskov Y., Döring M., Ower G., Vandepitte L., Hobern D., Remsen D., Schalk P., DeWalt R.E., Keping M., Miller J., Orrell T., Aalbu R., Adlard R., Adriaenssens E., Aedo C., Aescht E., Akkari N., Alonso-Zarazaga M.A., et al. Catalogue of Life Checklist (Nov 2018).

Newton A.F., Thayer M.K., Ashe J.S. & Chandler D.S. 2001. Staphylinidae Latreille, 1802. In: Arnett Jr J.H. & Thomas R.H. (eds) American Beetles. V. 1. Archostemata, Myxophaga, Adephaga, Polyphaga: Staphyliniformia. CRC Press LLC, Boca Raton, FL, USA.

Parker J. 2016. Myrmecophily in beetles (Coleoptera): evolutionary patterns and biological mechanisms. Myrmecological News 22: 65–108. Available from [accessed 11 Apr. 2022].

Poole R.W. & Gentili P. 1996. Nomina Insecta Nearctica: a Checklist of the Insects of North America. Volume 1 (Coleoptera, Strepsiptera). Entomological Information Services, Rockville, MD, USA. Available from [accessed 11 Apr. 2022].

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.

Ronquist F., Huelsenbeck J. & Teslenko M. 2012. MrBayes version 3.2 Manual: Tutorials and Model Summaries. Available from [accessed 11 Apr. 2022].

Schomann A.M. & Solodovnikov A. 2017. Phylogenetic placement of the austral rove beetle genus Hyperomma triggers changes in classification of Paederinae (Coleoptera: Staphylinidae). Zoologica Scripta 46 (3): 336–347.

Seevers C.H. 1965. The systematics, evolution and zoogeography of staphylinid beetles associated with army ants (Coleoptera: Staphylinidae). Fieldiana: Zoology 47: 138–351.

Smetana A. 2004. Family Staphylinidae (except subfamilies Pselaphinae and Scaphidiinae). In: Löbl I. & Smetana A. (eds) Catalogue of Palaearctic Coleoptera. Volume 2. Hydrophiloidea, Histeroidea, Staphylinoidea: 237–698. Apollo Books, Stenstrup.

Swofford D.L., Olsen G.J., Waddell P.J. & Hillis D.M. 1996. Phylogenetic Inference. In: Hillis D.M., Moritz D. & Mable B.K. (eds) Molecular Systematics, 2nd Edition: 407–514. Sinauer Associates, Sunderland, MA, USA.

Talavera G. & Castresana J. 2007. Improvement of phylogenies after removing divergent and ambiguously aligned blocks from protein sequence alignments. Systematic Biology 56 (4): 564–577.

Webster R.P. 2016. Checklist of the Coleoptera of New Brunswick, Canada. ZooKeys 573: 387–512.

Wickham H.F. 1898. On Coleoptera found with ants (fourth paper). Psyche 8 (226): 219–221.

Żyła D. & Koszela K. 2021. Redescription of the genus Megastilicus Casey (Staphylinidae, Paederinae) and the description of a new species. European Journal of Taxonomy 778 (1): 138–147.

Żyła D., Yamamoto S. & Jenkins Shaw J. 2019. Total-evidence approach reveals an extinct lineage of Paederinae rove beetles from Cretaceous Burmese amber. Palaeontology 62 (6): 935–949.

Żyła D., Bogri A., Heath T.A. & Solodovnikov A. 2021. Total-evidence analysis resolves the phylogenetic position of an enigmatic group of Paederinae rove beetles (Coleoptera: Staphylinidae). Molecular Phylogenetics and Evolution 157 (2): 107059.

How to Cite
Żyła, D., Tokareva, A., & Koszela, K. (2022). Phylogenetic position of genera Acrostilicus Hubbard and Pachystilicus Casey (Staphylinidae, Paederinae) and their redescription. European Journal of Taxonomy, 819(1), 1–22.
Research article