There are several similar species in the genus Dynastes, but only the Hercules beetle, Dynastes hercules is of a similar size (reaching 18 cm).  D. hercules has:

  • lighter coloured wing cases with black spotting
  • differently shaped horns
  • is usually found at lower elevations than D. neptunus
Dynastes hercules

Male Dynastes hercules a related species to the Neptune beetle.


The most closely related species is probably Dynastes satanas which is smaller than the Neptune beetle and is endemic to a restricted area of the Yungas in the Andes of Bolivia.


List of Dynastes species (after Móron, 2009):

Dynastes tityus - Eastern United States

Dynastes granti - Southwestern United States

Dynastes hyllus -  Mexico and Guatemala

Dynastes maya - Mexico, Guatemala and Honduras

Dynastes moroni - Mexico

Dynastes hercules - Southern Mexico to Bolivia, eastern Brazil and the lesser Antilles

Dynastes neptunus - Andes of Venezuela, Colombia, Ecuador and Peru

Dynastes satanas - Yungas of Bolivia