''Polposipus herculeanus'', the Frégate Island giant tenebrionid beetle or Frégate beetle, is a flightless species of

beetle Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describ ...

in family

Tenebrionidae Darkling beetle is the common name for members of the beetle family Tenebrionidae. The number of species in the Tenebrionidae is estimated at more than 20,000 and the family is cosmopolitan in distribution. Taxonomy ''Tenebrio'' is the Latin gen ...

. It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

Frégate Island Frégate Island (french: île de Frégate, link=no) is an island in Seychelles. The island is the easternmost of the granitic Inner Islands of the Seychelles (55 km (34 mi) east of Mahé). It is 2.07 square kilometres (0.80 square ...

in the

Seychelles Seychelles (, ; ), officially the Republic of Seychelles (french: link=no, République des Seychelles; Creole: ''La Repiblik Sesel''), is an archipelagic state consisting of 115 islands in the Indian Ocean. Its capital and largest city, V ...

. It grows to be about 20–30 mm long and has a hard, rounded abdomen covered with

tubercle In anatomy, a tubercle (literally 'small tuber', Latin for 'lump') is any round nodule, small eminence, or warty outgrowth found on external or internal organs of a plant or an animal. In plants A tubercle is generally a wart-like projection ...

s. There appears to be no

sexual dimorphism Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...

. They are largely

arboreal Arboreal locomotion is the Animal locomotion, locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. Th ...

, sheltering under the bark of trees, beneath the crooks of branches, and within bushes during the day. They are believed to be nocturnal, descending to the forest floor at night, though never travelling far. This behaviour may help them to avoid predators such as the

Wright's Skink Wright's skink (''Trachylepis wrightii''), also known Common name, commonly as Wright's mabuya, is a species of lizard in the Family (biology), family Scincidae. The species is Endemism, endemic to Seychelles. There are two recognized subspecies. ...

and the

Seychelles magpie-robin The Seychelles magpie-robin (''Copsychus sechellarum'') is a medium-sized endangered bird from the granitic Seychelles in the Indian Ocean. This species of magpie-robin is approximately in length. With a body mass of in females and in males, t ...

. When in danger, chemicals will secrete from the defensive glands in the posterior of the beetle, which have a musky smell and stains the skin purple. In captivity they have been noted to eat a variety of fruits, vegetables, bark, fungus and cat food. There are a few captive populations, taken for conservation reasons, the largest being at

London zoo London Zoo, also known as ZSL London Zoo or London Zoological Gardens is the world's oldest scientific zoo. It was opened in London on 27 April 1828, and was originally intended to be used as a collection for science, scientific study. In 1831 o ...

. These populations are the descendants of two small populations taken from the wild several years apart. It is quite possible that it previously lived on other islands in the

, and it has been suggested that it could be reintroduced to other islands to reduce its vulnerability. In captivity they have been recorded to live for up to seven years.

References

Sources

ARKive
Images *Nature Seychelles 2005
''Giant Tenebrionid Beetle''
Downloaded on 10 October 2009. Amanda Ferguson & Paul Pearce-Kelly (2004). Management guidelines for the welfare of zoo animals: The Frégate Island giant tenebrionid beetle Polposipus herculeanus Insects of Seychelles Tenebrionidae Endemic fauna of Seychelles Taxonomy articles created by Polbot Beetles described in 1848 {{Tenebrionidae-stub