Skip to main content Skip to main navigation menu Skip to site footer
Type: Article
Published: 2023-01-04
Page range: 127-136
Abstract views: 367
PDF downloaded: 46

A paradox indeed: description of genitalia and clarification of the subtribal classification of Pachyonychis paradoxus Clark and Pachyonychus paradoxus Melsheimer (Coleoptera: Chrysomelidae: Galerucinae: Alticini)

1Biodiversity Inventory for Conservation npo (BINCO), Walmersumstraat 44, 3380 Glabbeek, Belgium
Monte L. Bean Life Science Museum, Brigham Young University, Provo, Utah, U.S.A.
Systematic Entomology Laboratory, USDA, ARS, c/o Smithsonian Institution, National Museum of Natural History, Washington, District of Columbia, U.S.A.
5Department of Entomology, Smithsonian Institution, National Museum of Natural History, Washington, District of Columbia, U.S.A.
6Universidade Federal da Fronteira Sul, Rua Edmundo Gaievski, 1000, P. O. Box 253, 85770-000, Realeza, PR, Brazil.
Coleoptera Oedionychina Monoplatina flea beetle North America


Pachyonychis paradoxus Clark, 1860 and Pachyonychus paradoxus Melsheimer, 1847 are two species of Alticini whose strikingly similar names have led to significant confusion in the past. Recent study of American Oedionychina Chapuis, 1875 raised doubts about the validity of the subtribal placement of Pachyonychis Clark. Although general characteristics put this genus in Oedionychina, other features, especially the unusual shape of the pronotum, suggested that this monotypic genus would belong in Monoplatina Chapuis, 1875 instead. To collect evidence for the validity of its current placement, we compared external and genitalic morphology of both species to other members of Monoplatina and Oedionychina. Here we present images and descriptions of female genitalia for both species and male genitalia of Pachyonychus paradoxus Melsheimer, to our knowledge the first of their kind, and we conclude that the evidence supports the current subtribal placement of these two genera. Lectotypes are designated for both Pachyonychis paradoxus Clark and Pachyonychus paradoxus Melsheimer.



  1. Arnett, R.H. (1985) American Insects, a Handbook of the Insects of America North of Mexico. Van Nostrand Reinhold Company, New York, New York, 850 pp.
    Balsbaugh, E.U. & Hays, K.L. (1972) The leaf beetles of Alabama (Coleoptera: Chrysomelidae). Alabama Agricultural Experiment Station Bulletin. Auburn University, Auburn, Alabama, 223 pp.
    Blatchley, W.S. (1925) Notes on the distribution and habits of some Florida Coleoptera with descriptions of new species. The Canadian Entomologist, 57 (7), 160–168.
    Brimley, C.S. (1938) The Insects of North Carolina. North Carolina Department of Agriculture, Division of Entomology, Raleigh, 560 pp.
    Ciegler, J.C. (2007) Leaf and Seed Beetles of South Carolina (Coleoptera: Chrysomelidae and Orsodacnidae). Biota of South Carolina. Vol. 5. Clemson University, Clemson, 246 pp.
    Clark, H. (1860) Monograph of Halticidae in the collection of the British Museum. Physapodes and Aedipodes. Part I. Taylor and Francis, London, 301 pp.
    Clark, S.M. (2000) An annotated list of the leaf beetles of West Virginia (Coleoptera: Orsodacnidae, Megalopodidae, Chrysomelidae exclusive of Bruchinae). Occasional Publications of the West Virginia Department of Agriculture, 1, 1–93.
    Clark, S.M., LeDoux, D.G., Seeno, T.N., Riley, E.G., Gilbert, A.J. & Sullivan, J.M. (2004) Host plants of leaf beetle species occurring in the United States and Canada (Coleoptera: Megalopodidae, Orsodacnidae, Chrysomelidae, excluding Bruchinae). Coleopterists Society, Special Publication, 2, 1–476.[0243:HPOLBS]2.0.CO;2
    Crotch, G.R. (1873) Materials for the study of the Phytophaga of the United States. Proceedings of the Academy of Natural Sciences of Philadelphia, 25, 19–83.
    Dejean, P.F.M.A. (1836) Catalogue de la collection de coléoptères de M. le Comte Dejean. Mequignon-Marvis père et fils, Paris, 5, 361–443.
    Fattig, P.W. (1948) The Chrysomelidae or leaf beetles of Georgia. Emory University Museum Bulletin, 6, 1–47.
    Hall, S. L. & Barney, R.J. (2010) A quantitative method for assigning abundance classifications to leaf beetles (Coleoptera: Chrysomelidae) in Kentucky. Natural Areas Journal, 30 (1), 95–105.
    Heikertinger, F. (1925) Die Haticinengenera der Palaearktis und Nearktis. Bestimmungstabellen. (Monographie der palearktischen Halticinen: Systematischer Teil. Zweites Stück. Koleopterologische-Rundschau, 11 (3/4), 49–70. [Continuation of Heikertinger 1924: 25–48.]
    Horn, G. H. (1889) A synopsis of the Halticini of Boreal America. Transactions of the American Entomological Society, 16, 163–320.
    Jacoby, M. (1888) Notes on Some North American Species of Halticinæ (Group Monoplati). Transactions of the American Entomological Society and Proceedings of theEntomological Section of the Academy of Natural Sciences, 15 (4), 302–304.
    Jolivet, P. & Hawkeswood, T.J. (1995) Host-plants of Chrysomelidae of the World, an Essay about the Relationships between the Leaf-beetles and their Food-plants. Backhuys Publishers, Leiden, 281 pp.
    Kirk, V. M. (1969) A list of beetles of South Carolina, part 1—northern coastal plain. South Carolina Agricultural Experiment Station, Technical Bulletin, 1033, 1–124.
    Konstantinov A.S. (1998) Revision of the palearctic species of Aphthona Chevrolat and cladistic classification of the Aphthonini (Coleoptera: Chrysomelidae: Alticinae). Memoirs on Entomology, International, Associated Publishers, Florida, 429 pp.
    Konstantinov, A., Baselga, A., Grebennikov, V., Prena, J. & Lingafelter, S. (2011) Revision of the Palearctic Chaetocnema Species (Coleoptera: Chrysomelidae: Galerucinae: Alticini). Pensoft, Sofia, 363 pp.
    Konstantinov, A. & Konstantinova, A. (2011) New genus and species of flea beetles (Coleoptera, Chrysomelidae, Galerucinae, Alticini) from Puerto Rico, with comments on flea beetle diversity in the West Indies and a key to the West Indian Monoplatini genera. ZooKeys, 155, 61–87.
    Konstantinov, A.S. & Lingafelter, S.W. (2002) Revision of the Oriental species of Aphthona Chevro­lat (Coleoptera: Chrysomelidae). Miscellaneous Publication of the Entomological Society of Washington, Washington, 349 pp.
    Konstantinov, A.S., Van Roie, M., Furth, D., Clark, S.M. & Riley, E. (2022) Flea beetles of the West Indies: Subtribe Oedionychina Chapuis 1875, key to genera, new combinations, synonymy, checklist, and description of new genera and species (Coleoptera, Chrysomelidae, Galerucinae, Alticini). Journal of Insect Biodiversity, 33, 1–56.
    Melsheimer, F.E. (1847) Descriptions of new species of Coleoptera of the United States. Proceedings of the Academy of Sciences, Philadelphia, 3, 158–181.
    Mignot, E.C. (1969) Pachyonychis Clark and Pachyonychus Melsheimer: nomenclatural confusion. The Coleopterists’ Bulletin, 23 (4), 99–100.
    Peck, S.B. & Thomas, M.C. (1998) A distributional checklist of the beetles (Coleoptera) of Florida. Arthropods of Florida and Neighboring Land Areas, 16, 1–180.
    Riley, E.G., Clark, S.M., Flowers, R.W. & Gilbert, A.J. (2002) Chrysomelidae Latreille 1802. In: Arnett, R.H, Thomas, M.C., Skelley, P.E. & Frank, E.H. (Eds.), American Beetles. Volume 2. Polyphaga: Scarabaeoidea through Curculionoidea. CRC Press, Boca Raton, Florida, pp. 617–691.
    Riley, E.G., Clark, S.M. & Seeno, T.N. (2003) Catalog of the Leaf Beetles of America North of Mexico (Coleoptera: Megalopodidae, Orsodacnidae and Chrysomelidae, excluding Bruchinae). The Coleopterists Society, Sacramento, 290 pp.
    Schaeffer, C. (1932) Notes on some Halticinae with descriptions of new species (Col. Chrysomelidae). Bulletin of the Brooklyn Entomological Society, 27, 239–245.
    Staines, C.L. & Staines, S.L. (1998) The leaf beetles (Insecta: Coleoptera: Chrysomelidae): potential indicator species assemblages for natural area monitoring. In: Therres, G.D. (Ed.), Conservation of Biological Diversity: A Key to the Restoration of the Chesapeake Bay Ecosystem and Beyond. Maryland Department of Natural Resources, Annapolis, Maryland, pp. 233–244.
    Weise, J. (1921) Wissenschaftliche Ergebnisse der schwedischen entomologischen Reise des Herrn Dr. A. Roman in Amazonas 1914–1915. 6. Chrysomelidae. Arkiv för Zoologi, 14 (1), 1–205.