Beetles are insects from the order Coleoptera.
The word "coleoptera" is from the Greek koleos meaning "sheath" and pteron, meaning "wing", thus "sheathed wing".
The reason for the name is that most beetles have two pairs of wings, the front pair, the "elytra", being hardened and thickened into a sheath-like, or shell-like, protection for the rear pair, and for the rear part of the beetle's body.
The similarity of most beetles' shapes, in particular their possession of elytra, suggests that the Coleoptera are one group, but there is evidence in favour of allocating the current suborder Adephaga their own order.
Beetles are by far the largest orders of insects, with 350,000–400,000 species in four suborders (Adephaga, Archostemata, Myxophaga, and Polyphaga), making up about 40% of all insect species described.
Beetles are generally characterized by a particularly hard exoskeleton and hard forewings (elytra). The beetle's exoskeleton is made up of numerous plates called sclerites, separated by thin sutures. This design provides armored defenses while maintaining flexibility. The general anatomy of a beetle is quite uniform, although specific organs and appendages may vary greatly in appearance and function between the many families in the order. Like all insects, beetles' bodies are divided into three sections: the head, the thorax, and the abdomen. Also like all insects beetles have 3 pairs of legs.
Dynastinae or rhinoceros beetles are asubfamily of the scarab beetlefamily (Scarabaeidae) The Dynastinae are among the largest of beetles, reaching more than 150 mm (6 in) in length, but are completely harmless to humans because they cannot bite or sting. Some species have been claimed to lift up to 850 times their own weight Their common names refer to the characteristic horns borne only by the males of most species in the group. Each has a horn on the head and another horn pointing forward from the center of the thorax. The horns are used in fighting other males during mating season, The size of the horn is a good indicator of nutrition and physical health