Eumolpinae, Hope, 1840

Linzmeier, Adelita M., Moura, Luciano de A., Ribeiro-Costa, Cibele S., Manfio, Daiara, Agrain, Federico, Chamorro, Maria L., Morse, Geoffrey E., Regalin, Renato & Sekerka, Lukáš, 2024, An overview of the Brazilian Chrysomelidae (Insecta: Coleoptera): the most species-rich beetle family in Brazil, Zoologia (e 23092) 41, pp. 1-21 : 7-8

Eumolpinae

Eumolpinae Hope, 1840 are one of the largest subfamilies within Chrysomelidae , containing roughly 7,000 described species in at least 500 genera ( Jolivet et al. 2014). They are the least studied and known subfamily of leaf beetles, with enigmatic classifications at tribal and generic levels that are not well stablished. The tribal classification has not been studied in detail since Chapuis’ (1874) classification. As a result, many higher taxa are probably assemblages of phylogenetically unrelated species. Recent molecular data found Eumolpinae paraphyletic with respect to Cryptocephalinae and Cassidinae ( Gómez-Zurita et al. 2007, 2008).

Adult eumolpines are usually exophagous, feeding on foliage, while larvae are external root feeders. They are associated with a wide range of host plants, but prefer eudicots. The Neotropical fauna of Eumolpinae is diverse, with approximately 2,400 species and subspecies currently recognized as valid. Brazil is home to 947 documented species. Species of Megascelis Sturm, 1826 , Colaspis Fabricius, 1801 and Myochrous Erichson, 1847 have been reported causing considerable damage to agricultural crops, mainly soybean and corn, in Brazil. Many of these pests have been difficult to identify due to the lack of taxonomic revisions and information for the group (personal observation, AML).

Nearly half of the Brazilian species of Eumolpinae were described by Jan and Bohumila Bechyně (e.g., Bechyně 1949, 1953, 1954a, Bechyně and Bechyně 1964, 1968), who intensively studied Neotropical Eumolpinae . Despite their efforts, many descriptions are based on limited characters to delimit individual taxa. They also proposed numerous aberrations, which were later considered as infrasubspecific entities due to updates of the Code of Zoological Nomenclature (the infrasubspecific rank are not regulated by the Code (Article 1.3.4), since it is not considered an available name unless the provisions of Article 45.6 specify otherwise ( ICZN 1999)). Thus, they started to use subspecies instead. The use of male and female genitalia has only been recently implemented to distinguish among species ( Gómez-Zurita and Maes 2022) and are now considered to be fundamental morphological characters in Eumolpinae . Therefore, we expect that the current known diversity of eumolpines will increase with the examination of these features.