Agamopus castaneus Balthasar, 1938

Costa-Silva, Vinícius, Carvalho, Edrielly & Vaz-De, Fernando Z., 2022, A taxonomic revision of the New World genus Agamopus Bates, 1887 (Coleoptera: Scarabaeinae: Ateuchini), European Journal of Taxonomy 806 (1), pp. 64-89 : 67-69

Agamopus castaneus Balthasar, 1938

Figs 1 , 2B , 3

Agamopus castaneus Balthasar, 1938: 218 (original description).

Agamopus castaneus — Blackwelder 1944: 203 (catalogue). — Pereira 1947: 4 (key to the species of Agamopus ). — Balthasar 1965: 19 (comparison with other species). — Vulcano & Pereira 1967: 582 (key to the Amazonian dung beetles). — Halffter & Martínez 1968: 237 (diagnosis and key to the species of Agamopus ). — Bezděk & Hájek 2011: 360 (catalogue of type specimens housed in NMPC). — Larsen 2013: 95 (list of dung beetle species from Suriname). — Boilly & Vaz-de-Mello 2013: 104 (key to the Scarabaeinae from Guiana). — Feer 2013: 766 (dung beetles from French Guiana).

Differential diagnosis

Agamopus castaneus resembles A. unguicularis in its light brown colour and head completely covered by dense punctation, but the former can be distinguished by the presence of one row with two or three yellow setae on the pygidium ( Fig. 2B ). Agamopus unguicularis has a row of yellow setae disposed parallel to the anterior margin of the sulcus ( Fig. 2A ). Also, the completely unconnected geographical distribution of the two species can be used to separate them: A. unguicularis occurs in the centre of South America and A. castaneus occurs in the north of the continent.

Type material examined

Holotype (by original designation) ( Fig. 1A ) FRENCH GUIANA • ♀; first label [white, typeset]: “CAYENNE / Kourou Fl. / Le Moult”; second label [green with black border, Balthasar’s handwriting]: “ castaneus / m.”; third label [aged white, partly in Balthasar’s handwriting, partly typeset]: Agamopus / castaneus / Dr. V. Balthasar det.”; fourth label [red with black border]: “TYPUS”; fifth label [aged white, Ohaus’ handwriting]: “Ohaus determ / Uroxys / sp.”; sixth label [red, FZVM’s handwriting]: “HOLOTYPE ♀”; NMPC ( Fig. 1B ) .

Additional material examined (7 specimens)

FRENCH GUIANA – St. Laurent du Maroni • 1 ♂; Apr. 1976; P. Arnaud leg.; CEMT . – Cayenne • 1 ♂; Bénitier, La Trinité National Nature Reserve ; 8 Oct. 2010; SEAG leg.; CEMT .

BRAZIL – Roraima • 1 ♂, 1 ♀; Cantá, Serra Negra ; Sep. 1996; Ribeiro and Vaz-de-Mello leg.; CEMT . – Amapá • 3 ♂♂; Serra do Navio ; 0°53′6″ N, 51°52′53″ W; Sep. 2000; R. Ribon leg.; CEMT .

Geographic distribution

Agamopus castaneus is known from French Guiana and Suriname. Here we present the first record of this species from Brazil (Roraima and Amapá states) ( Fig. 3 ).

Figures

Fig. 1. Agamopus castaneus Balthasar, 1938. Holotype, ♀ (NMPC). A. Habitus, dorsal view. B. Labels. Length of specimen: 6.5 mm. Photographs: Jiří Hájek, NMPC.

Fig. 2. Ventral view of the abdomen. A. Agamopus unguicularis (Harold, 1883), dissected specimen (CEMT), with one row of several yellow setae along the anterior edge of the pygidial sulcus (black arrows). B. Agamopus castaneus Balthasar, 1938, dissected specimen (CEMT) with three (sometimes two) yellow setae in the centre of the pygidial disc (black arrows). Scale bars = 1 mm.

Fig. 3. Geographical distribution map of Agamopus joker sp. nov. (blue circle); A. unguicularis (Harold, 1883) (green circles); and A. castaneus Balthasar, 1938 (red circles).