Bittacus geniculatus Erichson, 1848

(Figs. 1d, 8l)

Bittacus geniculatus: Erichson, 1848:586; Esben-Petersen, 1921:150, 1927:13; Penny & Byers, 1979b:368; Willmann, 1983:55; Machado et al., 2009:36; Machado, 2018. Thyridates geniculatus: Collucci & Amorim, 2000:2 .

Holotype male: ZMHB (high resolution images examined). Species known from Guyana and Brazil (not possible to determine the state).

Bittacus geniculatus is a unique species, and rarely collected. It is known only by the male holotype from Guyana and another specimen from Brazil, reported by Esben-Petersen (1927) and held in the Helsinki museum. This specimen is likely from one of the Amazonian Brazilian states. Willmann (1983) did not include B. geniculatus in Thyridates, mainly because the first fork of Rs in the forewing does not form a right angle. However, the species was transferred to Thyridates by Collucci & Amorim (2000), who includes it in the “group angrensis ”, based on its falcate forewing. Bittacus geniculatus, can be easily distinguished from the remaining species based on its extremely long pterostigma, Rs 1+2 not forking, and by the elongated male epandrium.