Gromphas amazonica, Bates, 1870, Bates, 1870

Cupello, Mario, 2024, The genus Gromphas Dejean, 1836 (Coleoptera, Scarabaeinae): nomenclature, distribution, and conservation, including a contribution to the debate on electronic publications in zoology, Zoosystema 46 (2), pp. 23-59 : 44-45

ON SOME MISLABELLED SPECIMENS OF GROMPHAS AMAZONICA HOUSED IN THE BRUSSELS MUSEUM (RBINS)

While examining the collection of the Institut royal des Sciences naturelles de Belgique, Brussels ( RBINS), for this work, I realised that, quite surprisingly, all the specimens of G. amazonica housed there either are certainly mislabelled or bear suspicious provenance data.To prevent future misunderstandings and the potential publication of erroneous geographical records, it is relevant to address these specimens here. Two males gifted along with 759268 other insects to the RBINS in 1939 or before (one with accession number 12.595) and originating from the collection of the French insect dealer Eugène Le Moult (1882-1967) bear information saying they were collected in the municipality of Uberaba, state of Minas Gerais, in central Brazil and within the Cerrado ecoregion. A series of three males and seven females from the same gift (same accession number) are labelled as if coming from the town of Muzo, in the Colombian department of Boyacá, and within the Magdalena Valley. Finally, a male and a female, these from a lot of 26488 insects acquired by the RBINS from J. J. Gillet on 5th October 1935 (accession number 10.640), are said to have been caught in Paraguay without further data. Since, based on trustworthy data, G. amazonica is known only from localities along the Huallaga, Pisqui, Ucayali, Juruá, and Amazon Rivers, in the Amazon rainforest ( Cupello & Vaz-de-Mello 2013, 2015; see Fig. 5 ), these three records, all of which lying outside that area, are most likely incorrect.

Janssens (1940) examined the two Gillett specimens supposedly from Paraguay and considered that they indicated that G. amazonica is much more widely distributed than its previously thought Amazonian restriction (e.g., in Bates 1870; d’Olsoufieff 1924). In my opinion, he was wrong in accepting the label content at face value. In regard to the Muzo ( Colombia) record, which could be argued to be the least improbable given the strong biotic influence from Amazonia in the Magdalena Valley, Alejandro Lopera (personal communication to MC, 7th February 2020), a specialist in the Colombian dung beetle fauna, informed me that the area near Muzo and the rest of the Magdalena River Basin ‘have been well sampled, so if it were a correct location it should have been reported by now’ (see, e.g., Medina et al. 2012). This strengthens my confidence that the Muzo record is indeed incorrect. It is noteworthy, however, that G. aeruginosa , the other typically Amazonian species of Gromphas , is known from reliable specimens to have been collected at least three times between 1979 and 1982 at a locality in the upper Magdalena Valley, the Colombian town of Gigante (Huila) ( Cupello & Vaz-de-Mello 2013). Therefore, if, against my expectation, G. amazonica does prove to be present there, it will not be unprecedented for an Amazonian Gromphas .

MATERIAL EXAMINED. — Brazil. Amapá • 1 ♂ [genitalia dissected], 1 ♀; Macapá, BR-156, Km 14; 26.XI.1981 [in cow dung]; I. S. Gorayeb and team leg.; MPEG. — Amazonas • 1♂ [genitalia dissected]; Benjamin Constant; IX.1955; I. C. Lima leg.; ex Alvarenga collection; DZUP .

Peru. Loreto • 3 ♂ [all with genitalia dissected], 2 ♀; Ucayali, Contamana; XII.2001; no collector; TAMU.

Erroneous data: Brazil. — Minas Gerais • 2 ♂ [both with genitalia dissected]; Uberaba; no further data; ex Le Moult collection (one with accession number 12.595); RBINS . — Colombia. Boyacá • 3 ♂ [all with genitalia dissected], 7 ♀; Occidente, Muzo; no further data; ex Le Moult collection (all with accession number 12.595); RBINS . — Paraguay • 1 ♂, 1 ♀; no further data; ex J. J. Gillet collection (accession number 10.640); RBINS .

Figures

FIG. 5. — Updated distribution map of the six species of Gromphas. Data retrieved from Cupello & Vaz-de-Mello (2013, 2015), Damborsky et al. (2015), Cajaiba et al. (2017), Gámez & Acconcia (2018), Alonso et al. (2019), Uchoa & Rodrigues (2019), Bitencourt et al. (2019), Noriega et al. (2021), and the material examined for this work.