Description of Onthophagus humboldti and Uroxys bonplandi, two new scarab beetles (Coleoptera, Scarabaeidae, Scarabaeinae) from Costa Rica, with notes on tropical mountain brachyptery and endemicity

Researchers have identified two new endemic scarab beetle species, Onthophagus humboldti and Uroxys bonplandi, from Costa Rica's Talamanca Range-La Amistad Reserves. Notably, O. humboldti is the tenth brachypterous (short-winged) species in the genus Onthophagus globally, showcasing extreme brachyptery within this group. The study also reveals that tropical mountain ranges like the Cordillera de Talamanca exhibit higher levels of endemism and brachyptery than lowland rainforests, challenging conventional beliefs. By analyzing mitochondrial DNA, the research supports the distinctiveness of two closely related Onthophagus species groups: O. dicranius and O. clypeatus. Additionally, a biogeographical model suggests that stable environments in deeply incised valleys during the Last Glacial Maximum may have promoted brachyptery in scarab beetles.

Kohlmann, B., Solís, Á., & Alvarado, G. (2019). Description of Onthophagus humboldti and Uroxys bonplandi, two new scarab beetles (Coleoptera, Scarabaeidae, Scarabaeinae) from Costa Rica, with notes on tropical mountain brachyptery and endemicity. ZooKeys, 881, 23–51. https://doi.org/10.3897/zookeys.881.38026