Dinacoma

• D. caseyi Blaisdell, 1930
• D. marginata (Casey, 1887)
• D. sanfelipe Gillett, Osborne, Reil, & Rubinoff, 2020

In 2006, entomologists indicated that there were two apparently new species or subspecies of Dinacoma, collected respectively from near the city of Hemet, California, and in the northwest portion of Joshua Tree National Park, California, at Covington Flats.[1] As of 2022, these specimens of Dinacoma have not been formally described in the scientific literature, but expert evaluation places them in the Dinacoma marginata species group.[2] La Rue (2006, p. 2) stated that Dinacoma caseyi is the most morphologically divergent and distinct species in the genus. The new specimens collected from the Hemet area are paler than Casey's June beetle specimens and possess morphologically different genitalia.[2] Furthermore, the Little San Bernardino Mountains geographically isolate the new Dinacoma Joshua Tree population from all other known Dinacoma species.

 This article incorporates public domain material from Endangered and Threatened Wildlife and Plants; 12-Month Finding on a Petition To List the Casey’s June Beetle (Dinacoma caseyi) as Endangered With Critical Habitat (PDF). United States Fish and Wildlife Service.

• Blaisdell, F.E. (1930), "Revision of the genus and species of Dinacoma with description of a new species (Coleoptera: Scarabaeidae)", Pan-Pacific Entomologist, 6: 171–177
• Fish and Wildlife Service (5 July 2007), "Endangered and Threatened Wildlife and Plants; 12-Month Finding on a Petition To List the Casey's June Beetle (Dinacoma caseyi) as Endangered With Critical Habitat", Federal Register, 72 (128): 36635–36646, 72 FR 36635
• La Rue, Delbert (13 June 2006), Electronic mail communication to Alison Anderson, Entomologist, Carlsbad Fish and Wildlife Office, Carlsbad, CA. Cited in Fish and Wildlife Service (2007)