https://doi.org/10.11646/zootaxa.4624.4.11 http://zoobank.org/urn:lsid:zoobank.org:pub:93E193EA-E589-4C87-83F5-FD46901DDF38 ZOOTAXA ISSN 1175-5326 (print edition) ISSN 1175-5334 (online edition) Accepted by A.B.T. Smith: 29 May 2019; published: 2 Jul. 2019 593 Zootaxa 4624 (4): 593–593 https://www.mapress.com/j/zt/ Copyright © 2019 Magnolia Press Correspondence A new Ateuchus guatemalensis (Bates, 1887) (Coleoptera: Scarabaeidae) synonym from Mexico BERT KOHLMANN Universidad EARTH, AP 4442-1000, San José, Costa Rica. E-mail: bkohlman@earth.ac.cr This note reports on placement of Ateuchus benitojuarezi Moctezuma, Sánchez-Huerta, & Halffter, 2018 (Coleoptera: Scarabaeidae: Scarabaeinae: Ateuchini) as a junior synonym of Ateuchus guatemalensis (Bates, 1887) new synonymy. Ateuchus guatemalensis was originally described from Guatemala and is now known from Chiapas (Mexico), Honduras, and Nicaragua (Kohlmann & Vaz-de-Mello 2018). With the new synonym discussion below, A. guatemalensis also occurs in the Chimalapas region in Oaxaca (Mexico), thus following a very typical biogeographic distribution pattern known from other dung beetles that encompasses the Pacific slope between the Isthmus of Tehuantepec to the Nicaraguan lakes (Solís & Kohlmann 2012). Recently, Moctezuma et al. (2018) described a new species from Oaxaca named Ateuchus benitojuarezi Moctezuma, Sánchez-Huerta, & Halffter, 2018. The characters they used to diagnose their new species were the existence of an apical spiniform process of the “canoe-shaped” copulatory accessory lamella (only known in A. guatemalensis; homologous to the frontolateral peripheral sclerite (FLP) of Tarasov & Génier 2015), which is part of the normal variation of acces- sory copulatory lamellae in Ateuchus; and a slightly V-shaped clypeus (their photograph shows a specimen with a highly eroded clypeus), where the A. benitojuarezi paratypes I examined show the typical broadly V-shaped clypeus (just like in A. guatemalensis). A decisive and basically invariant character in the identification of Ateuchus is the shape of the copula- tory hooks of the internal sac of the aedeagus, which is identical in A. benitojuarezi and A. guatemalensis. Additionally, A. guatemalensis is the only Mesoamerican species that has a distinctly punctate thorax, a distinctly convex pygidium, and an almost effaced anterior pronotal margin, which were all observed in the A. benitojuarezi paratypes I examined. Moct- ezuma et al. (2018) cite 8.1 mm as the mean length for A. benitojuarezi; however, the measurements of the four studied paratypes have a mean of 7.25 mm (it is unclear if the originally published mean was incorrect of if I only had smaller paratypes available for study). Lastly, Moctezuma et al. (2018) did not mention any specific specimens of A. guatemalen- sis used for making comparisons, so it is unclear if their observations were based on specimen comparisons or only based on previously published descriptions. After examining paratypes (kindly provided by G. Halffter) of A. benitojuarezi and comparing them with A. guatemalensis material from Las Flores, Masaya, Nicaragua; El Zumbador, San Marcos, Gua- temala; and Unión Juárez, Chiapas, Mexico; the following synonym is established: Ateuchus benitojuarezi Moctezuma, Sánchez-Huerta, & Halffter, 2018 = Ateuchus guatemalensis (Bates, 1887) new synonymy. References cited Bates, H.W. (1887) Lamellicornia. (Copridae, Aphodiidae, Orphnidae, Hybosoridae, Geotrupidae, Trogidae, Aclopidae, Chas- matopteridae, Melolonthidae). In: Godman, F.D. & Salvin, O. (Eds.), Biologia Centrali Americana, Insecta, Coleoptera. 2. R.H. Porter, London, pp. 25–160. Kohlmann, B. & Vaz-de-Mello, F. (2018) A new key for the species of Ateuchus Weber (Coleoptera: Scarabaeidae: Scarabaei- nae) occurring in Mexico, with description of the first North American inquiline species from a rodent burrow (Rodentia: Geomydae) and new distribution records. Revista Brasileira de Entomologia, 62, 131–134. https://doi.org/10.1016/j.rbe.2018.01.002 Moctezuma, V., Sánchez-Huerta, J.L. & Halffter, G. (2018) Two new species of Ateuchus with remarks on ecology, distribu- tions, and evolutionary relationships (Coleoptera, Scarabaeidae, Scarabaeinae). ZooKeys, 747, 71–86. https://doi.org/10.3897/zookeys.747.22731 Solís, A. & Kohlmann, B. (2012) A checklist and distribution atlas of the Scarabaeinae (Coleoptera: Scarabaeidae) of Costa Rica. Zootaxa, 3482, 1–32. Tarasov, S. & Génier, F. (2015) Innovative Bayesian and parsimony phylogeny of dung beetles (Coleoptera, Scarabaeidae, Scarabaeinae) enhanced by ontology-based partitioning of morphological characters. PLOS One, 10 (3), e0116671. https://doi.org/10.1371/journal.pone.0116671