Elephant beetle  (Megasoma elephas)

The elephant beetle has yet to be classified by the IUCN.

One of the giants of the insect world, the elephant beetle (Megasoma elephas) is a large and distinctive tropical beetle with a long, rhinoceros-like horn on its head. This unusual structure is found only in the male (2) (3) (6), and is used in combat with other males (2) (7).

The adult elephant beetle has a shiny black body, with a reddish-yellow or brown furry covering (2) (6) (7). The horn of the male also has a furry covering (6) and is upward-curving, splitting into two at the tip (2) (3). In addition to the long horn on the head, the pronotum of the male elephant beetle bears a smaller, central horn and a triangular horn on each side (3). The female elephant beetle is distinguished from the male by its lack of horns (3) (6).

Like the adult, the larva of the elephant beetle also reaches an enormous size (2). The larva is typically curved in shape (2) and has a dark brown to black head (3). The pupa of the elephant beetle is oval, elongate and stout, and dark reddish in colour. In the male pupa, the developing horns of the adult beetle are visible (3).

Two subspecies of elephant beetle were previously recognised: Megasoma elephas elephas and Megasoma elephas occidentalis. However, M. e. occidentalis is now generally considered to be a separate species, Megasoma occidentalis (8) (9).

The elephant beetle occurs in Central and South America, from south-eastern Mexico south to Colombia and Venezuela (1) (3) (6).

The elephant beetle inhabits a variety of tropical forests, including tropical plantations and sometimes forest remnants, at elevations up to around 1,000 metres (2) (3).

Adult elephant beetles are active at night, particularly between September and January, and are often attracted to artificial lights (2) (3) (6). The diet of the adult beetle is likely to include flowers and fruit, and it is also known to feed on the sap from recently cut twigs (3) (6).

Interestingly, the elephant beetle is able to increase its own body temperature metabolically when the air around it cools, in a manner more like that of a small mammal than an insect (4).

Male elephant beetles use their impressive horns to fight rival males for access to females or to feeding sites (2) (7). The female elephant beetle is believed to lay eggs in holes in living or dead trees, often within the abandoned nest of a bird or mammal. The larvae feed on organic material within the hole (3) (6) and may also feed on the rotten wood of the cavity’s walls (3).

Although elephant beetle larvae have sometimes been found in rotten logs and stumps on the ground, the adults are thought to generally live in the forest canopy, with the female typically laying the eggs in the upper parts of trees (3). In captivity, the larvae of this species have been reared on a mixture of rotten wood, forest soil and dry cow dung (3) (5).

The larvae of the elephant beetle take two to three years to mature (3) (5) (6), and spend around 38 to 44 days in the pupal stage before developing into adults (5). The elephant beetle larva can reach impressive weights of up to 86 grams, and can eat its way through an amazing 1.5 kilograms of organic matter as it develops (5).

The main threat to the elephant beetle is likely to be habitat loss (6) (7), due to the selective logging and burning of the mature trees required by its developing larvae (6).

Like other Megasoma species (rhinoceros beetles), the elephant beetle is also likely to be collected for the pet trade (6) (9), and its horns may be used in handicrafts and jewellery (6) (10). The horns are also seen by some as symbols of sexual and physical power, and are sometimes ground up and consumed by local people (2).

Although its global status has yet to be assessed by the IUCN, the elephant beetle has been classified as ‘Near Threatened’ in the Red Book of Terrestrial Invertebrates of Colombia (6).

There are not known to be any specific conservation measures currently in place for the elephant beetle, but greater protection of its forest habitat has been recommended as one of the most important actions for the conservation of this giant insect (6).

Find out more about the elephant beetle and its conservation:

• Amat-García, G., Andrade-C., M.G. and Amat-García, E. (Eds.) (2007) Libro Rojo de los Invertebrados Terrestres de Colombia. Instituto de Ciencias Naturales - Universidad Nacional de Colombia, Conservación Internacional Colombia, Instituto Alexander von Humboldt and Ministerio de Ambiente, Vivienda y Desarrollo Territorial, Bogotá. Available at:
  http://www.fundacionbiodiversa.org/pdf/jj/libro%20rojo%20invertebrados.pdf