Gromphas dichroa Blanchard, 1846

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 : 34

Gromphas dichroa Blanchard, 1846

Gromphas dichroa Blanchard, 1846: 182 [18th December 1846].

NAME-BEARING TYPE. — Holotype by monotypy (female), MNHN.

TYPE LOCALITY. — Uruguay: Montevideo, ‘near the sea’ ( Blanchard 1846).

ETYMOLOGY. — A New Latin first-class adjective in the nominative case meaning ‘having two colours’, ‘bicoloured’ ( Wiktionary 2022). The word ultimately derives from the combination of the Ancient Greek prefix δῐ- (di -), meaning ‘twice’, ‘double’ ( Brown 1954; Wiktionary 2023a), and the Ancient Greek noun ΧΡῶμᾰ (khrôma), meaning ‘colour’, ‘pigment’, especially of the skin or body surface ( Bailly 1895; Liddell & Scott 1897; Brown 1954), Latinized by the addition of the Latin adjectival suffix - us (- a, - um) ( Wiktionary 2023b). The name makes an obvious reference to the dorsal colouration of the holotype, with a centrally red pronotum and blue elytra, a pattern seen in many ‒ but not all ‒ individuals of the species ( Cupello & Vaz-de-Mello 2013, 2015; see more details later in this work). Blanchard (1846) called the species in his vernacular French the ‘ gromphas bicolore ’.

DISTRIBUTION. — The Pampas biome and peripheral areas of the southern Atlantic Forest (e.g., Itapiranga, Santa Catarina, and Nova Petrópolis, Rio Grande do Sul) in southern Brazil, Argentina, and Uruguay; possibly also present in the southern Humid Chaco of Paraguay. Nothing is known about the habitats occupied by the species in this vast area. One possibility, based on what is known of the biology of the other Gromphas , is that the species occupies more humid areas, especially wetlands, including the floodplains and sandbanks of the Uruguay River along the border of Argentina and the Brazilian state of Rio Grande do Sul and other such water bodies like Lake Guaíba (e.g., in Porto Alegre) and the River Plate (e.g., Montevideo and Buenos Aires).