Megasoma occidentale Bolívar y Pieltain, Jiménez-Asúa, and Martínez, 1963 Male, dorsal view	Megasoma occidentale Bolívar y Pieltain, Jiménez-Asúa, and Martínez, 1963 Female, dorsal view

male, lateral view

female, lateral view Photos by Matthew R. Moore

 

Distribution: Mexico (Sinaloa and Oaxaca) (Ratcliffe and Morón 1997; Morón and Gómez-Anaya 2002).

Diagnosis: Males with short, recumbent setae on elytra and pronotum; females with short, recumbent setae on elytra. Males with anterior tibiae arcuate. Anterior angles of pronotum produced into laterally facing horns. Females with pronotum rugose. Scutellum at base rugose. Pronotum without longitudinal, posteromedian carina.

Biological Data: The habitat of M. occidentale is tropical deciduous forest between sea level and 700 m in elevation. Larvae have been found in rotten stems of coconut palms (Morón 1977). Adults are attracted to lights at night (Ratcliffe and Morón 2005).

Temporal Distribution: The few specimens examined exhibited a date range from November-December.

Larvae: Morón (1977) described the third instar larvae.

References:
Morón, M.A. 1977. Description of the third-stage larva of Megasoma elephas occidentalis Bolívar et al. (Coleoptera: Scarabaeidae). Coleopterists Bulletin 31: 339-345.

Morón, M.A. and J.A. Gómez-Anaya. 2002. Consideraciones sobre la catergoría taxonómica de Megasoma elephas occidentalis Bolívar y Pieltain, Jiménez-Asúa, y Martínez, 1963 (Coleoptera: Melolonthidae; Dynastinae). Folia Entomológica Mexicana 41: 299-319.

Ratcliffe, B.C. and M.A. Morón. 2005. Larval descriptions of eight species of Megasoma Kirby (Coleoptera: Scarabaeidae: Dynastinae) with a key for identification and notes on biology. Coleopterists Bulletin 59: 91-126.

Ratcliffe, B.C. and M.A. Morón. 1997. Capítulo 3. Dynastini [pp. 53-98]. In: (M.A. Morón, B.C. Ratcliffe, and C. Deloya, editors) Atlas de los Escarabajos de Mexico (Coleoptera: Lamellicornia). Vol. 1. Familia Melolonthidae. CONABIO and Sociedad Mexicana de Entomologia, México. 280 pp.