Australambrysus fraternus (Montandon, 1897)

(Figs. 1, 13)

Ambrysus fraternus Montandon, 1897b: 128 (original description).

Australambrysus fraternus: Reynoso-Velasco & Sites 2021: 12 (changed combination).

Discussion. Ambrysus fraternus was described based on material collected in the central region of Brazil, although without specific locality data (Montandon 1897b). The type locality is identified as "Goyaz à Cuyaba", currently referring as two distinct localities: Vila Boa de Goyaz (=Goyaz), in the State of Goiás, and Cuiabá (=Cuyaba), in the State of Mato Grosso. The author did not provide information on the number of specimens in the type series; however, it apparently consists only of the male holotype, which is deposited at the MNHN. This species is mentioned in the literature mainly in taxonomic catalogs (e.g., De Carlo 1950; La Rivers 1971; Moreira et al. 2011), and the lack of illustrations makes its identification difficult. Reynoso-Velasco & Sites (2021) provisionally transferred this species to Australambrysus, although they noted that confirmation is needed. Here, we provide photos of the holotype in different views (Fig. 1).

Although the holotype has not been dissected, the propleura are tightly appressed to the probasisternum and prosternellum, thereby concealing part of the prosternellum (Fig. 1B). Furthermore, this species also shares other characteristics common to the species recently included in the Australambrysus plax species complex by Sites (2023a), such as: the dorsal color of the body, the posterolateral angles of abdominal segments IV–VI spinose, and the pattern of golden pubescence on the ventral surface of the abdomen. Thus, this species is a member of Australambrysus, and is here included in the Australambrysus plax species complex.

Type material examined. HOLOTYPE ♂, by monotypy (MNHN), [BRAZIL], Goyaz à Cuyaba, De Castelnau 6-47 / Ambrysus fraternus Montand., type 1897 / Type / Museum Paris, MNHN EH 25356.