Aegognathus waterhousei Leuthner, 1883 (Figure 2c: holotype male) Aegognathus waterhousei Leuthner, 1883: 445 (original combination and description) Examined material Type material. Holotype male examined from photographs labelled as follows: ′(a) white typed and green bordered label, ′ Peru / 79 17̍; (b) white typed label, ′162̍; (c) illegible; (d) red circled label, ′ Type ̍; € white typed and handwritten label, ′ Aegopsis [sic] waterhousei Type ̍. 1 J̍ (NHM). Additional material Peru, Arpayo, Satipo, Junín, ii. 2008, G. Pross. 1J (CERPE). Diagnosis Body entirely black with some bluish and reddish reflections. Head and pronotum finely punctate. Mandibles with truncate to rounded apex. Elytra strongly punctate with yellowish scale-like setae. Last abdominal ventrites carinate along lateral margins, also presenting a transverse carina on the anterior margin of ventrites III–V. Last abdominal ventrite presenting two lateral tubercles with a group of setae at the apex. Aedeagus almost four times longer than wide, cross bar ′X̍ shaped with two acuminate projections at the posterior margin. For the complete description see Cáceres et al. (2019). Distribution Southern Peru, Central Cordillera, Ucayali-Rondônia provinces (Morrone et al. 2022). Remarks Despite being the type species of the genus, A. waterhousei is barely represented among collections. Other specimens from different collections of CERPE, LBC, and UNSM previously identified as A. waterhousei were actually another species, Aegognathus arnaudi Cáceres, Ríos-Málaver and Grossi, 2019. To our knowledge the only specimens properly identified as A. waterhousei are the holotype, deposited at NHM, and one male collected in 2008, deposited at CERPE.

Published as part of Cáceres, Juan Sebastián D. & Grossi, Paschoal Coelho, 2023, Taxonomic revision of Aegognathus Leuthner, 1883 (Coleoptera: Lucanidae), pp. 557-595 in Journal of Natural History 57 (9 - 12) on pages 570-571, DOI: 10.1080/00222933.2023.2198736, http://zenodo.org/record/7975445