Lucanidae Latreille, 1804

Costa-Silva, Vinícius da, Ferreira, André da Silva, Bordin, Bruna R., Basílio, Daniel S., Rodrigues, Diego F., Gama, Emanuel R. R., Fuhrmann, Juares, Mariano, Júlia, Bevilaqua, Marcus, Cherman, Mariana A., Duarte, Paulo R. M., Grossi, Paschoal C. & Vaz-de-Mello, Fernando Z., 2024, Brazilian Scarabaeoidea (Insecta: Coleoptera) in the Taxonomic Catalogue of the Brazilian Fauna, with a key for families and subfamilies, Zoologia (e 23075) 41, pp. 1-37 : 11-12

Lucanidae Latreille, 1804

Figs 4J–L, 6C

Diagnosis. Species of Lucanidae can be easily recognizable by the strong sexual dimorphism, with males presenting extremely elongate mandibles in most cases (as showed in the Figs 4J, 6C), although some taxa could be confused with other Coleoptera families. In Brazil, Lucanidae can be distinguished from other Scarabaeoidea families by the presence of three ( Lucaninae ) to six ( Syndesinae ) antennal lamellae, scape as long as funicle, and antennae usually geniculate ( Fig. 6C). Tarsal claws always simple; ninth abdominal segment modified in a well-developed genital capsule; aedeagus in most cases with a permanently everted internal sac, except in the genus Psilodon Perty, 1830 ( Syndesinae ).

Remarks. Lucanids are the most diverse family of the first lineages of Scarabaeoidea , with around 1,805 worldwide described species, 147 genera in eight subfamilies, three of which are extinct ( Schoolmeesters 2023). In Brazil there are currently 75 species representing two of the five living subfamilies ( Grossi 2023). The Brazilian lucanids were first studied by Luederwaldt (1930, 1931b, 1934c, 1935), and after him, and before the 2000s, four species were described in Brazil ( Benesh 1937, Lacroix 1982, Bomans and Arnaud 1996). During the last 20 years, field work and studies on Brazilian stag-beetles have increased, and the family has been subject of new taxon descriptions, immature descriptions, life history approaches and reclassification of some genera ( Grossi et al. 2003, Grossi and Vaz-de-Mello 2007, Grossi and Paulsen 2009, Grossi 2009, Grossi et al. 2012, Silva and Grossi 2019, Cáceres et al. 2023). Lucaninae are by far, the most diverse subfamily in Brazil and the World, comprising more than 90% of World Lucanid fauna. While the Syndesinae encompasses only three currently described species for Brazil, there will be at least twice that number described in an ongoing revision of Psilodon .

Among the Brazilian lucanid genera, Altitatiayus Weinreich, 1960 , and probably Zikanius Grossi & Paulsen, 2009 , and Montesinus Grossi, 2016 have underground behavior, with larvae feeding on grass roots. However, most other genera have larvae that feed on dead wood, decayed or not, and pupate in the wood, with only Psilodon pupating in the ground (see Grossi and Aguiar 2014). Genera like Leptinopterus Hope, 1838 , Macrocrates Burmeister, 1847 , Metadorcus Parry, 1870 Metadorcinus Kriesche, 1922 , Casignetus MacLeay 1819 , and Charagmophorus Waterhouse, 1895 can be collected during daylight, flying at mountain peaks, or feeding on sap flows. Other genera like Sclerostomus Burmeister, 1847 and Psilodon have nocturnal habits, being attracted to light traps.