''Hexarthrius mandibularis'' is one of the world's largest

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 ...

. It belongs to the

tribe The term tribe is used in many different contexts to refer to a category of human social group. The predominant worldwide usage of the term in English language, English is in the discipline of anthropology. This definition is contested, in p ...

Lucanini, in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Lucanidae 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 ...

. This beetle has a dull, dark, brick reddish body. Both the legs and antennae are blackish. The most notable characteristic are the large, antler-like

mandible In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower tooth, teeth in place. The mandible sits beneath the maxilla. It is the only movabl ...

s. These have small teeth running down the inside edge, with one large, forward-pointing pair located approximately a third of the way down from the tips. The tips are forked inward somewhat. During the

larval stage 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 l ...

, ''Hexarthrius mandibularis'' lives in rotten hardwood, feeding on it. Later, during the imago stage, it consumes tree juice.

Subspecies

There are two subspecies, both native to

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...

: *''Hexarthrius mandibularis mandibularis'' Deyrolle, 1881 ::This subspecies grows to a maximum length of 115 mm. It is indigenous to

Kalimantan Kalimantan () is the Indonesian portion of the island of Borneo. It constitutes 73% of the island's area. The non-Indonesian parts of Borneo are Brunei and East Malaysia. In Indonesia, "Kalimantan" refers to the whole island of Borneo. In 2019, ...

. *''Hexarthrius mandibularis sumatranus'' Mizunuma, 1994 ::This subspecies grows to a maximum length of 118.5 mm. It is indigenous to

Sumatra Sumatra is one of the Sunda Islands of western Indonesia. It is the largest island that is fully within Indonesian territory, as well as the sixth-largest island in the world at 473,481 km2 (182,812 mi.2), not including adjacent i ...

References

External links

Close up image of mandibles

Image
Lucaninae Beetles described in 1994 {{Lucanidae-stub