Megasoma thersites LeConte, 1861 male, dorsal view	Megasoma thersites LeConte, 1861 female, dorsal view

male, lateral view

female, lateral view Photos by Matthew R. Moore

Distribution: Mexico (Baja California [Bahia de La Paz, south]).

Diagnosis: Males with elytra and pronotum pilose; females with elytra and pronotum pilose. Males with anterior tibiae straight. Anterior margins of clypeus with acute, spiniform teeth separated by three tooth widths or more. Pronotum with median, anteriorly directed horn. Distance between apices of anterior angles (horns) of pronotum nearly twice width of head. Females with pronotum punctate. Anterior margins of clypeus with acute, spiniform teeth. Frontoclypeal suture with transverse, blunt tubercle. Tubercle impressed on top.

Biological Data: Adults can be found on the branches of “palo verde” (Cercidium peninsulare Rose, Caesalpinaceae) where they feed on the cambium by “gumming” away the bark layer (Ratcliffe 2005). Adults are found at elevations from sea level to 600 m (Hardy 1972). Males and females are attracted to lights (Ratcliffe 2005).

Temporal Distribution: September-October (Ratcliffe 2005).

Larvae: Ratcliffe and Morón (2005) described the first, second, and third instar larvae.

References:
Hardy, A.R. 1972. A brief revision of the North and Central American species of Megasoma (Coleoptera: Scarabaeidae). Canadian Entomologist 104: 765-777.

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.