Belostoma fittkaui De Carlo, 1966

(Figs. 3E, 10A)

Known distribution: Known only from the type series, which only includes males (Cachoeira stream, Cuieiras river, Amazonas, Brazil) (De Carlo, 1966).

Material examined: 2 males and 2 females,ethyl alcohol 70%, BRAZIL, Amazonas, Barcelos municipality, Demini river, 00°38’05.3”S 62°51’52.7”W, 24.IX.2014, A.M.O. Pes et al. colls., F. Stefanello, 2018 det.; 1 female, ethyl alcohol 70%, Santa Isabel do Rio Negro municipality, Maruiá river, 19.IX.2014, A.M.O. Pes et al. colls., F. Stefanello, 2018 det.; 1 female, ethyl alcohol 70%, Careiro da Várzea municipality, Purupuru lake, BR 319, 08.VIII.2012, N. Hamada col., F. Stefanello,2018 det. 3 males and 4 females, ethyl alcohol 70%, Roraima, Caracaraí municipality, Pretinho stream, near Jufari river, 00°57’45.6”S 62°06’40.2”W, 29.IX.2014, A.M.O. Pes et al. colls., F. Stefanello, 2018 det.

Notes: This species is poorly cited in the literature and unknown by many researchers working on giant water bugs. There were doubts about its taxonomic status and its range of distribution. The females of this species had not been described. Here, we examined eight females with body length of 30.1-33.6 mm and greatest width of body of 14.1-16.0 mm. The color is dark brown, and the body is flattened. The distribution is apparently related to the Negro river and its tributaries in Amazonas state. This species appears to be relatively abundant in these places. As reported by Roback & Nieser (1974), the general appearance, structural characters and structure of genitalia place this species in the B. bergi group of Lauck (1964). On the other hand, segment 1 of the rostrum is distinctly shorter than 2 and is likely to place it in B. discretum group. Finally, the abdominal sternites completely covered with hair makes B. fittkaui very different from other Brazilian species.This species is close to B.hirsutum Roback & Nieser, 1974 (a Colombian species occurring in llanos and Amazon regions), which has the abdomen totally covered with hair and, similar to B.fittkaui, which has segment 1 of he rostrum distinctly shorter than 2. This is the first record of B. fittkaui to Roraima state (Brazil).