Zootaxa 1037: 29-36 (2005) ISSN 1175-5326 (print edition) www.mapress.com/zootaxa/ ZOOTAXA Copyright © 2005 Magnolia Press ISSN 1175-5334 (online edition) A new species of Megasoma Kirby (Coleoptera: Scarabaeidae: Dynastinae) from Sinaloa, Mexico MIGUEL-ANGEL MORON Departamento de Entomologia, Instituto de Ecologia, A.C. Apdo. Postal 63, Xalapa, Veracruz 91000, Mexico. E-mail: moron_ma@ecologia.edu.mx Abstract A new species, Megasoma nogueirai sp. nov., from tropical subdeciduous forests at 290-820 m of altitude in Sinaloa, northwestern Mexico, is described and illustrated. Differences with M. elephas (F.) and M. occidentalis Bolivar, Jimenez and Martinez, are outlined. Key words: Coleoptera: Dynastinae, Dynastini, Megasoma, taxonomy, Mexico Introduction The genus Megasoma Kirby is formed by 14 species clearly defined by sound morphological characters and precise geographic and ecological distributions (Table 1) (Endrodi 1941,1977; Hardy 1972; Lachaume 1985; Moron and Gomez-Anaya 2002) . In addition, the polemic Megasoma janus Felsche, has been cited as valid species or as subspecies of M. actaeon (L.) (Endrodi 1977; Lachaume 1985; Silvestre and Arnaud 2002). Mainly supported by differences in the shape of male horns and geographic distribution, six subspecies of M. elephas (Fab.), M. joergenseni Bruch, M. janus and M. gyas Herbst were also described (Fischer 1968, Silvestre and Arnaud 2002, Nagai 2003). Recent collection trips in the state of Sinaloa, Mexico, provided specimens of an undescribed species of Mega- soma. Illustrations were made with a digital camera (Sony Mavica CD500 ) and a scanning electron microscope (Jeol JSM-5600 LV). Measurements were obtained using an electronic digital caliper (0-100 mm). Specimens are deposited in the collections of the Canadian Museum of Nature, Ottawa (CMNC), Instituto de Biologia, Universidad Nacional Autonoma de Mexico, Mexico City (IBUNAM), Instituto de Ecologia, A.C Xalapa (IEXA), The Natural History Museum, London (BMNH), Museum national dÒHistoire naturelle, Paris (MNHN), University of Nebraska State Museum (UNSM), Zoologische Museum der Humboldt University, Berlin (ZMHU), M.A. Moron, Xalapa (MXAL), G. Nogueira, Guadalajara, Mexico (GNGC), and D. Curoe, Mexico City (DCC). 1037 Accepted by P. Johnson: 24 Jun. 2005; published: 19 Aug. 2005 29 ZOOTAXA 1037 TABLE 1. Distribution of species and subspecies of Megasoma M. actaeon (Linne 1758) - Panama to Bolivia M. anubis Chevrolat 1836 - Parana to Rio Grande do Sul, Brazil M. cedrosa Hardy 1972 - Northern Baja California, Mexico M. elephas (Fabricius 1775) - Veracruz, Mexico to Panama M. e. iijimai Nagai 2003 - Colombia and Venezuela M. gyas (Herbst 1775) - Minas Gerais to Sao Paulo, Brazil M. g. rumbucheri Fischer 1968 - Guyana to NE Brazil M. g. porioni Nagai 2003 - Bahia, Brazil M. janus Felsche 1906 - S. Bolivia, Paraguay, N. Argentina and S. Brazil M. j. ramirezorum Silvestre et Arnaud 2002 - Southern Colombia and Ecuador M. j. fujitai Nagai 2003 - Mato Grosso, Brazil M. joergenseni Bruch 1910 - Northern Argentina M. j. penyai Nagai 2003 - Chaco, Paraguay M. lecontei Hardy 1972 - Sierra Laguna, Baja California Sur, Mexico M. mars Reiche 1852 - Upper amazonic basin M. nogueirai sp. nov. - Sinaloa, Mexico M. occidentalis Bolivar, Jimenez et Martinez 1963 - Nayarit to Oaxaca, Mexico M. pachecoi Cartwright 1963 - Southern Sonora, Mexico M. punctulatus Cartwright 1952 - Arizona, U.S.A. M. sleeperi Hardy 1972 - Southern California, U.S.A. M. thersites LeConte 1861 - Southern Baja California Sur, Mexico M. vogti Cartwright 1963 - S. Texas to Nuevo Leon and Tamaulipas, Mexico Megasoma nogueirai Moron, sp. nov. - Sinaloa, Mexico