The rhinoceros stag beetle (''Sinodendron cylindricum''), also known as the horned stag beetle, or simply the rhinoceros beetle, is a species of

stag beetle Stag beetles are a family of about 1,200 species of beetles in the family Lucanidae, currently classified in four subfamilies.Smith, A.B.T. (2006). A review of the family-group names for the superfamily Scarabaeoidea (Coleoptera) with corrections ...

native to Europe. It is characterised by a clear sexual dimorphism.

Description

The

beetles 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 ...

reach a body length of 12 to 16 millimeters and have a very shiny, black body, sometimes with turquoise sheen. Despite being in the family Lucanidae (stag beetles), they look rather like true

rhinoceros beetles Dynastinae or rhinoceros beetles are a subfamily of the scarab beetle family (Scarabaeidae). Other common names – some for particular groups of rhinoceros beetles – include Hercules beetles, unicorn beetles or horn beetles. Over ...

, which are well known for their rhinoceros-like horn. The body is cylindrical and the elytra and thorax have distinct rows of pits and grooves. The males have a well-developed horn on their heads, which is significantly smaller in the females. In addition, the cavities on the pronotum in the female are much shallower than the distinct cavities in the male. The larvae are white and soft with brown heads.

Distribution and habitat

With the exception of southwestern Spain and Portugal and northern Scandinavia, the species occurs throughout the European continent and the British Isles to western Siberia. The beetle prefers primary deciduous forests at cooler and higher altitudes, but can also be found in old willow stands, avenue and street trees, parkland, hedgerows, and fruit trees.

Lifecycle and diet

Lifecycle

Like all beetles, these insects go through

complete metamorphosis Holometabolism, also called complete metamorphosis, is a form of insect development which includes four life stages: egg, larva, pupa, and imago (or adult). Holometabolism is a synapomorphic trait of all insects in the superorder Endopterygota. ...

, starting as a larva, which is soft and white going through several instars before becoming a pupa and then reaching maturity, emerging in Spring or Summer. The

larvae A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. The ...

develop mainly in white rotten wood of various deciduous trees, varying from tree stumps to logs. The range of proven food plants includes oak,

beech Beech (''Fagus'') is a genus of deciduous trees in the family Fagaceae, native to temperate Europe, Asia, and North America. Recent classifications recognize 10 to 13 species in two distinct subgenera, ''Engleriana'' and ''Fagus''. The ''Engle ...

, birch, alder, hornbeam, aspen, willow, linden, maple, horse chestnut,

ash Ash or ashes are the solid remnants of fires. Specifically, ''ash'' refers to all non-aqueous, non- gaseous residues that remain after something burns. In analytical chemistry, to analyse the mineral and metal content of chemical samples, ash ...

rowan The rowans ( or ) or mountain-ashes are shrubs or trees in the genus ''Sorbus ''Sorbus'' is a genus of over 100 species of trees and shrubs in the rose family, Rosaceae. Species of ''Sorbus'' (''s.l.'') are commonly known as whitebeam, r ...

, apple,

cherries A cherry is the fruit of many plants of the genus ''Prunus'', and is a fleshy drupe (stone fruit). Commercial cherries are obtained from cultivars of several species, such as the sweet ''Prunus avium'' and the sour ''Prunus cerasus''. The nam ...

, pears, plums and firs. In addition, the species is often associated with the flat lacquer polypore (''

Ganoderma applanatum ''Ganoderma applanatum'' (the artist's bracket, artist's conk, artist's fungus or bear bread) is a bracket fungus with a cosmopolitan distribution. Description This fungus is parasitic and saprophytic, and grows as a mycelium within the wood o ...

''), the tinder fungus ('' Fomes fomentarius'') and the oak fire agaric ('' Fomitiporia robusta''). Their development takes three to four years, pupation takes place in the wood.

Diet

''S. cylindricum'' larvae feed on rotting wood, whereas the adults feed on tree sap.

Conservation

The species is rare in Central Europe, it is listed as " endangered" (category 3) in the Red List of Threatened Species in Germany, only in North Rhine-Westphalia is the species considered "endangered" (category 2) and in other federal states as " potentially endangered". In Baden-Württemberg this species is not classified as endangered.

References

{{DEFAULTSORT:Sinodendron Cylindricum Lucanidae Beetles described in 1758 Taxa named by Carl Linnaeus Beetles of Europe