What is "hercules beetle"

Dynastidan \Dy*nas"ti*dan\, n. [Gr. ?, fem. of ?. See Dynast. The name alludes to the immense size of some species.] (Zo["o]l.) One of a group of gigantic, horned beetles, including Dynastus Neptunus, and the Hercules beetle ( Dynastus Hercules) of tropical America, which grow to be six inches in length.

The Hercules beetle (Dynastes hercules) is the most famous and the largest of the rhinoceros beetles. It is native to the rainforests of Central America, South America, and the Lesser Antilles. It is the largest of the six species in the Dynastes genus, and one of the largest beetles known, up to in length it is only exceeded by two other beetles in the family Cerambycidae, Macrodontia cervicornis (specimens of 17–17.5 cm are known) and Titanus giganteus (also up to 17–17.5 cm; several 18+ cm specimens are reputed/alleged to exist). However, if the horns are excluded, both M. cervicornis and D. hercules drop considerably farther down in the size rankings, leaving T. giganteus on top. One reason for this is that the development of the horns is allometric, as well as sexually dimorphic, and thus not strictly correlated to actual body size; it is possible for a female to be much longer, measured from eyes to abdomen, than a male, yet be considered "smaller" simply due to the absence of horns.

As noted above, Hercules beetles are highly sexually dimorphic, with the females generally being larger-bodied but much shorter, as they lack horns entirely. The larval stage of the Hercules beetle will last one to two years, with the larva growing up to in length and weighing more than 100 grams. Much of the life of the larva is spent tunneling through its primary food source of rotting wood. After the larval period, transformation into a pupa, and moulting, the beetle then emerges as an adult. Adults will roam the forest floor in search of decaying fruit.

Anecdotal reports exist of the Hercules beetle being able to carry up to 850 times its body mass but actual measurements on a much smaller (and relatively stronger: see square-cube law) species of rhinoceros beetle shows a carrying capacity only up to 100 times their body mass, at which point they can barely move.