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Issue: Vol. 5829 No. 1: 11 Jun. 2026
Type: Monograph
Published: 2026-06-11
DOI: 10.11646/zootaxa.5829.1.1
Page range: 1-85
Abstract views: 23
PDF downloaded: 1

Revision of the Metallactus humeralis species-group (Coleoptera: Chrysomelidae: Cryptocephalinae)

Via San Rocco; 17 22030 Castelmarte; Italy
Coleoptera Entomology taxonomy new synonym redescription Pachybrachini Neotropical Region new species

Abstract

Nine species of Griburius Haldeman, 1849 and three species of Metallactus Suffrian, 1866, previously regarded as valid, together with two taxa previously treated as synonyms, are revised and critically discussed. According to the recent new diagnosis of Metallactus, all treated taxa are assigned to this genus. The following nomenclatural changes and synonymies are proposed: Metallactus corruscans (Suffrian, 1866) comb. nov. (= Scolochrus tripudians Suffrian, 1866 syn. nov.); Metallactus callens (Suffrian, 1866) comb. nov.; Metallactus diabolicus (Suffrian, 1866) comb. nov.; Metallactus fallax (Suffrian, 1866) stat. restit., comb. nov. (= Metallactus polymorphus Suffrian, 1866 syn. nov.); Metallactus humeralis (Stål, 1857) comb. nov.; Metallactus leucopygus (Suffrian, 1866) comb. nov.; Metallactus quadrillum (Suffrian, 1866) comb. nov.; Metallactus triguttatus (Fabricius, 1801) comb. nov. (= Cryptocephalus perlatus (Olivier, 1808) syn. nov.). Metallactus nigroornatus (Stål, 1857) and Metallactus flavopustulatus (Stål, 1857) are confirmed as valid species. Pachybrachis pustuliger (Stål, 1857) is confirmed as a junior synonym of Metallactus nigroornatus. Type series of all treated species were traced and a lectotype is designated for each of them. Redescriptions of all the species are provided. Additionally, Metallactus acaciae sp. nov. from Bolivia, Metallactus atripennis sp. nov. from Brazil, Metallactus australis sp. nov. from Argentina, Metallactus cuiabanus sp. nov. from Bolivia and Brazil, Metallactus flavoapicalis sp. nov. from Brazil, Metallactus flavosuturalis sp. nov. from Argentina, Bolivia and Paraguay, Metallactus juliae sp. nov. from Argentina, Brazil and Paraguay, Metallactus konstantinovi sp. nov. from Costa Rica and Panama, Metallactus nigrobrunneus sp. nov. from Brazil, Metallactus ornaticollis sp. nov. from Brazil, Metallactus panatahua sp. nov. from Peru, Metallactus seminiger sp. nov. from Argentina, Bolivia, Brazil, Paraguay, Metallactus tacana sp. nov. from Bolivia are described as new to science. Illustrations and distributional data of all the treated species are provided. Pending a future phylogenetic analysis of the genus, all taxa are provisionally assigned to the same morphologically coherent assemblage, here referred to as Metallactus humeralis species-group. Scolochrus (= Griburius) leucurus was originally described (Suffrian, 1866) as belonging to the same species group revised here. However, its type series appears to be lost, consequently, its taxonomic validity and its possible relationship with the species treated in the present study remain unconfirmed.

References

  1. Blackwelder, R.E. (1946) Checklist of the Coleopterous Insects of Mexico, Central America, the West Indies, and South America. Part 4. Bulletin of the United States National Museum, 185, 551–763. https://doi.org/10.5479/si.03629236.185.4
  2. Burlini, M. (1968) Revisione delle specie italiane e della maggior parte delle specie europee del genere Pachybrachis Chevr. (Coleoptera Chrysomelidae). XXII Contributo alla conoscenza dei Cryptocephalini. Memorie della Società Entomologica Italiana, 47, 11–116.
  3. Chevrolat, L.A.A. (1836) [new taxa]. In: Dejean, P.F.M.A., Catalogue des coléoptères de la collection de M. le Comte Dejean. [1833–1836]. Méquignon-Marvis Père et Fils, Paris, pp. 1–443. [DP, pp. 361–443: 31 December 1836 (Bousquet 2016)]
  4. Clavareau, C.H. (1913) Pars 53: Chrysomelidae: Megascelinae, Megalopodinae, Clytrinae, Cryptocephalinae, Chlamydinae, Lamprosominae. In: Schenkling, S. (Ed.), Coleopterorum Catalogus. W. Junk, Berlin, 278 pp.
  5. Fabricius, J.C. (1801) Systema eleutheratorum secundum ordines, genera, species, adiectis synonimis, locis, observationibus, descriptionibus. Tomus II. Impensis Bibliopolii Academici Novi, Kiliae, 687 pp.
  6. GBIF.org (2026a) (Metallactus Suffrian, 1866) GBIF Occurrence Download. Available from: https://doi.org/10.15468/dl.nhd29g (accessed 18 February 2026)
  7. GBIF.org (2026b) (Griburius Haldeman, 1849) GBIF Occurrence Download. Available from: https://doi.org/10.15468/dl.ucyzk9 (accessed 18 February 2026)
  8. Hadley, A. (2010) CombineZP Image Stacking Software. Version June 2010. Available from: http://www.hadleyweb.pwp.blueyonder.co.uk (accessed 23 December 2016)
  9. Haldeman, S.S. (1849) Cryptocephalinarum Boreali-Americae diagnoses cum speciebus novis musei lecontiani. Journal of the Academy of Natural Sciences of Philadelphia, 2 (1), 245–265.
  10. Horn, W. & Kahle, I. (1935) Über entomologische Sammlungen, Entomologen & Entomo-Museologie. Entomologische Beihefte aus Berlin-Dahlem, 2, 1–160.
  11. Horn, W.W., Kahle, I., Friese, G. & Gaedike, R. (1990) Collectiones Entomologicae: eine Kompendium über den Verbleib entomologischer Sammlungen der Welt bis 1960. Akademie der Landwirtschaftswissenschaften der DDR, Berlin, 220 pp.
  12. ICZN [International Commission on Zoological Nomenclature] (1999) International code of zoological nomenclature. Fourth Edition. International Trust for Zoological Nomenclature, London, 306 pp.
  13. iNaturalist contributors, iNaturalist (2026). iNaturalist Research-grade Observations. iNaturalist.org. Occurrence dataset. https://doi.org/10.15468/ab3s5x
  14. Olivier, A.G. (1808) Entomologie, ou histoire naturelle des insectes, avec leurs caractères génériques et spécifiques, leur description, leur synonymie et leur figure enluminée. Coléoptères. Tome sixième. Paris, Desray, 613–1104.
  15. Perty, M. (1832) Delectus animalium articulatorum, quae in itinere per Brasiliam annis MDCCCXVII-MDCCCXX jussu et auspiciis Maximiliani Josephi I. Bavariae regis augustissimi peracto collegerunt Dr. JB de Spix et Dr. CF Ph. de Martius: accedit dissertatio de insectorum in America Meridionali habitantium vitae genere moribus et distributione geographica. Impensis Editoris, Monachii, 224 pp.
  16. Redtenbacher, L. (1848) Fauna Austriaca. Die Käfer. Nach der analytischen Methode. [1847–1849], Wien: Carl Gerold, xxvii + 883 pp., 2 pls.
  17. Sachtleben, H. (1961) Nachträge zu “Walther Horn & Ilse Kahle: Über entomologische Sammlungen“. Beiträge zur Entomologie = Contributions to Entomology, 11 (5–6), 481–540.
  18. Sassi, D. (2018) Revision of the Metallactus kollari species-group with a new diagnosis of the genus (Coleoptera: Chrysomelidae: Cryptocephalinae). Zootaxa, 4413 (1), 57–110. https://doi.org/10.11646/zootaxa.4413.1.2
  19. Sassi, D. (2019) Revision of the Metallactus hamifer species-group (Coleoptera: Chrysomelidae: Cryptocephalinae). Zootaxa, 4657 (2), 201–245. https://doi.org/10.11646/zootaxa.4657.2.1
  20. Sassi, D. (2020) Revision of the Metallactus generosus species-group with a preliminary evaluation of the effectiveness of the endophallus morphology in distinguishing critical sibling species (Coleoptera: Chrysomelidae: Cryptocephalinae). Zootaxa, 4877 (1), 148–162. https://doi.org/10.11646/zootaxa.4877.1.6
  21. Sassi, D. (2022) Revision of the Metallactus taeniatellus species group (Coleoptera: Chrysomelidae: Cryptocephalinae). Zootaxa, 5125 (3), 251–282. https://doi.org/10.11646/zootaxa.5125.3.1
  22. Sassi, D. (2023) Revision of the Griburius scutellaris (Fabricius, 1801) species group (Coleoptera: Chrysomelidae: Cryptocephalinae). Zootaxa, 5315 (6), 501–548. https://doi.org/10.11646/zootaxa.5315.6.1
  23. Sassi, D. (2024a) Revision of the Griburius posticatus (Suffrian, 1866) species group (Coleoptera: Chrysomelidae: Cryptocephalinae). Zootaxa, 5406 (2), 201–237. https://doi.org/10.11646/zootaxa.5406.2.1
  24. Sassi, D. (2024b) Revision of the Metallactus minax Suffrian, 1866 species-group (Coleoptera: Chrysomelidae: Cryptocephalinae). Zootaxa, 5583 (1), 071–086. https://doi.org/10.11646/zootaxa.5583.1.3
  25. Sassi, D. & Montagna, M. (2021) The Central and South American Pachybrachina Site. World Wide Web electronic publication. Version January 2021. Available from: http://www.chrysomelidae.it/amer-pachy/ (accessed 14 February 2026)
  26. Schöller M. (2024) Tribe Pachybrachini Chapuis, 1874. In: Bezděk J. & Sekerka J. (Eds) Catalogue of Palaearctic Coleoptera. Chrysomeloidea II (Orsodacnidae, Megalopodidae, Chrysomelidae). Volume 6/2. Updated and revised second edition. Brill, Leiden-Boston, pp. 677–685. https://doi.org/10.1163/9789004443303
  27. Stål, C. (1857) Till kännedomen af Phytophaga. Öfversigt af Kongeliga Vetenskaps–Akademiens Förhandlingar, Stockholm 14, 53–63.
  28. Suffrian, E. (1852) Zur Kenntnis der Nordamerikanischen Cryptocephalen. Linnaea Entomologica, 7, 1–238.Suffrian, E. (1866) Zur Kenntnis der Südamerikanischen Cryptocephalen. Linnaea Entomologica, 16, 1–483.

How to Cite

Sassi, D. (2026) Revision of the Metallactus humeralis species-group (Coleoptera: Chrysomelidae: Cryptocephalinae). Zootaxa, 5829 (1), 1–85. https://doi.org/10.11646/zootaxa.5829.1.1