Belongs within: Eumolpinae.
Brilliant leaf beetles
Published 31 August 2025
The leaf beetles of the Chrysomelidae include some eye-catching representatives, among the most spectacular of which are the species of the genus Eumolpus. This genus includes some of the largest of all leaf beetles, growing over fifteen millimetres in length, with all species being brilliantly metallic in coloration. Yet despite their admirable appearance, Eumolpus species do not appear to be extensively studied.
About forty species of Eumolpus, and numerous subspecies, were recognised in a revision of the genus by Špringlová (1960). The genus is Neotropical in distribution with most species found in the tropics and subtropics of South America. A single species, E. robustus, is found in Central America and Mexico; it has been recorded as far north as Arizona but there seems to be some uncertainty whether it is found there now (Riley et al. 2002). As well as its metallic coloration, Eumolpus is characterised by bifid claws and a longitudinal groove on the pygidium. Špringlová (1960) distinguished Eumolpus from the closely related Longeumolpus by its less elongate, oval body shape, harder integument and shorter penis in males.
A handful of European species, most notably Chrysochus asclepiadeus, have historically been included in Eumolpus by some European authors. This was the result of confusion over the type species of Eumolpus, which was not originally established for the South American species now associated with the name. The identity of Eumolpus was conserved by action of the ICZN (2012) which ratified the more commonly used sense of the genus over the original but far less recognised concept.
Like many related genera, Eumolpus species feed as adults on the leaves of Apocynaceae (including species historically assigned to Asclepiadaceae). The larvae are subterranean feeders on roots. The adult’s choice of diet appears to be defensive, as toxins from the plant are sequestered for the beetle’s own protection. However, feeding on these plants is made challenging by the copious amounts of latex they produce. Some genera related to Eumolpus simply wipe their mandibles against the leaf surface on a regular basis to remove the latex; others cut open the leaf vein below where they wish to feed. What the preferred method is for Eumolpus species seems to have not yet been established.
Systematics of Eumolpus
Eumolpus Weber 1801 [incl. Alphites Chapuis 1874, Eudoxus Kirby 1837; Eumolpites]RC02
| i. s.: E. cyanellus Dejean in Boisduval 1835B35
| E. pictus Perty 1832 [incl. Balya quadrimaculata Jacoby 1882]L90b
| E. quadripunctatusL02
| E. robustus (Horn 1885)RC02
|--E. (Eumolpus)LC40
| |--E. (E.) arenariusLC40
| |--E. (E.) obscurusLC40
| |--E. (E.) pretiosusLC40
| |--E. (E.) surinamensis Fabr. 1775LC40, L90a
| `--E. (E.) vitisLC40 [=Cryptocephalus (E.) vitisG20]
`--E. (Eudora)LC40
|--E. (E.) antennatusLC40
`--E. (E.) compressicornisLC40
*Type species of generic name indicated
References
[B35] Boisduval, J. B. 1835. Voyage de Découvertes de l’Astrolabe. Exécuté par ordre du Roi, pendant les années 1826–1827–1828–1829, sous le commandement de M. J. Dumont d’Urville. Faune entomologique de l’océan Pacifique, avec l’illustration des insectes nouveaux recueillis pendant le voyage vol. 2. Coléoptères et autres ordres. J. Tastu: Paris.
[G20] Goldfuss, G. A. 1820. Handbuch der Naturgeschichte vol. 3. Handbuch der Zoologie pt 1. Johann Leonhard Schrag: Nürnberg.
ICZN. 2012. Eumolpus Weber, 1801, Chrysochus Chevrolat in Dejean, 1836 and Bromius Chevrolat in Dejean, 1836 (Insecta, Coleoptera, Chrysomelidae): usage conserved. Bulletin of Zoological Nomenclature 69 (2): 147–149.
[LC40] Laporte de Castelnau, F. 1840. Histoire Naturelle des Insectes Coléoptères vol. 2. P. Duménil: Paris.
[L02] Latreille, P. A. 1802. Histoire Naturelle, générale et particulière des crustacés et des insectes vol. 3. Familles naturelles des genres. F. Dufart: Paris.
[L90a] Lefèvre, É. 1890a. Voyage de M. E. Simon au Venezuela (Décembre 1887–Avril 1888). 6e mémoire. Clytrides, lamprosomides et eumolpides. Annales de la Société Entomologique de France, 6e série 9: 329–336.
[L90b] Lefèvre, É. 1890b. Descriptions d’un genre nouveau et de plusieurs nouvelles espèces de coléoptères phytophages de la famille des Eumolpídes. Annales de la Société Entomologique de France, 6e série 9: 337–340.
[RC02] Riley, E. G., S. M. Clark, R. W. Flowers & A. J. Gilbert. 2002. Chrysomelidae Latreille 1802. In: Arnett, R. H., Jr, M. C. Thomas, P. E. Skelley & J. H. Frank (eds) American Beetles vol. 2. Polyphaga: Scarabaeoidea through Curculionoidea pp. 617–691. CRC Press.
Špringlová, B. 1960. Essai monographique du genre Eumolpus (Coleoptera Phytophaga). Mémoires de Institut Royal des Sciences Naturelles de Belgique, 2nd ser. 60: 1–79.