Oryctes

Oryctes[1] is the economically most important genus of rhinoceros beetles in the subfamily Dynastinae (family: Scarabaeidae) and includes serious pests of palm trees.

[4][5] The species are typically between 30 and 60 mm long, dark brown to black, with a robust body and a strong cuticle.

They can be distinguished from other genera in the tribe Oryctini by the structure of the pronotum, the horn on the head, the mouthparts and other features.

Eight species (Oryctes amberiensis, O. anguliceps, O. augias, O. clypealis, O. colonicus, O. dollei, O. politus and O. ranavalo) are endemic to Madagascar and occur nowhere else.

It is widespread in most European countries and has been also reported from some of the neighbouring regions like parts of northern Africa, the Near East and Turkey.

Other Asia/Pacific species include Oryctes ata in Turkmenistan, O. centaurus in Papua New Guinea, O. forceps in northern India ("British Bootan, Padong"), O. gnu (Malaysia, Indonesia, Thailand, the Philippines, and southern China), O. heros in Timor, O. hisamatsui in Japan, and O. nudicauda in Myanmar.

[5] The species of Oryctes can be distinguished from other genera in the subfamily Dynastinae and the tribe Oryctini by a combination of different morphological features.

A number of Oryctes species cause damage to palm trees and are regarded as agricultural pests.

The beetle bore into the centre of the palm crown, starting at one of the middle leaf axils.

For example, they may invade and damage the top part of the trunk or feed on the roots and the new shoots at the base of the palm.

[23] However, the name was first used by Hellwig in a note a few months earlier who wrote that he initiated the work on the beetles of Prussia, but did not have time to complete it and handed it over to Illiger.

[24][5] However, the genus name Oryctites has been considered to be taxonomically invalid and there are doubts if the species fossilis belongs to Oryctes.

Distribution ranges of the species in the genus Oryctes (blue outline) and that of Oryctes nasicornis , the type species (brown outline)
Frontal view of Oryctes nasicornis male with some characteristic features of the genus Oryctes labelled
Tip of the abdomen of Oryctes nasicornis with the right elytron removed to show the stridulation area with a section enlarged. A = right hindwing (ala), E = left elytron, PP = propygidium, P = pygidium
Immature stages of Oryctes nasicornis
Coconut palm in Hawaii, heavily damaged by Oryctes rhinoceros attacks.
Oryctes agamemnon male - Left: shape of pronotum with central depression (concavity) and two knobs at the hind margin - Right: hind tibia showing 3 fixed (immovable) spikes and 2 movable processes (subgenus Rykanoryctes ).