Identification key and distribution of Adisianus species 1 Frontal head with pointed and almost smooth spine-like chaetae; manubrium with 6+6 chaetae; dorsal dens with 19 or less chaetae............................................. A. maassius (Palacios-Vargas & González, 1995) (Mexico) - Frontal head with rough blunt chaetae; manubrium with 7+7 or 8+8 chaetae; dorsal dens with 21 or more chaetae......... 2 2 Ant III with two rough blunt chaetae, Ant I lacking such structures; frontal head B line with 1+1 rough blunt chaetae; male with 4+4 genital chaetae...................................................... A. maculatus (Bretfeld, 2002) (Brazil) - Ant I and III with one rough blunt chaeta, each; frontal head B line lacking rough blunt chaetae; male with 6+6 or 7+7 genital chaetae............................................................................................. 3 3 Lateral body strongly pigmented; frontal head lacking unpaired chaetae; tenaculum with two chaetae; manubrium with 8+8 chaetae.................................................................. A. fuscus (Bretfeld, 2002) (Brazil) - Lateral body weakly pigmented; frontal head with one unpaired chaeta; tenaculum with three chaetae; manubrium with 7+7 chaetae....................................................................... A. pinheadi sp. nov. (Brazil)

Published as part of Rodrigues, Iandra Vitória Bezerra, Medeiros, Gleyce Da Silva, Nunes, Rudy Camilo & Bellini, Bruno Cavalcante, 2025, The rare Adisianus Bretfeld (Collembola, Bourletiellidae): a new species from Northeastern Brazil and an identification key to the genus, pp. 580-594 in Zootaxa 5632 (3) on page 593, DOI: 10.11646/zootaxa.5632.3.10, http://zenodo.org/record/15372276