Dorcus titanus

Males measure 32.0–111.3 millimetres (1.26–4.38 in) including mandibles; females 36.5–54 millimetres (1.44–2.13 in). It has an elongated, somewhat flat body dull black with blackish antennae and legs. Male's antler-like jaws have small teeth along inner edge and a pair of big teeth toward the bottom, and are forked at end. The head of a large male reaches nearly the length of its prothorax and abdomen combined.[2]

Adults can be seen from May to August. They feed on tree juice, especially of Quercus species. Females lay eggs on the underground part of fallen oaks. The eggs hatch in about a month and the larvae feed on rotten wood. The larval period lasts about one year. The complete life cycle can last approximately from 1 to 2 years.[2]

This species is widely distributed in Indonesia, the Philippines, Malaysia, Thailand, Vietnam, Laos, Myanmar, India, Japan, China, Taiwan and Korea.[1][3]

It mainly inhabits tropical rainforests and temperate forests from lowland to mountains.[2]

This beetle has some commercial value and export from some regions is criminalized. There are some Asian cultures that assign aphrodisiac properties to this insect, high in protein. However, most are imported for sport, decorative show, or to be kept as an exotic pet. This stag beetle is also popular pet in Asia and Europe.

• 
  Male
• 
  Larva
• 
  Museum specimen
• 
  Mounted specimen from Sulawesi (Celebes)

Hiroshi Fujita, a Japanese coleopterologist studying stag beetles, described over the 20 subspecies separating some subspecies to 11 subspecies in Japan. Also, He divided D. titanus titanus in Malay Archipelago into D.titanus yasuokai, D. titanus typhon, D. titanus nobuyukii and more subspecies. Fujita's subspecies are listed in here, however, these are in arguing.

Dorcus titanus platymelus

• Dorcus titanus castanicolor - Tsushima, Korean Peninsula (넓적사슴벌레/(in Korean)), Mainland China
• Dorcus titanus daitoensis - Daitō Islands
• Dorcus titanus elegans
• Dorcus titanus fafner - Vietnam
• Dorcus titanus hachijoensis
• Dorcus titanus imperialis - the Philippines
• Dorcus titanus karasuyamai
• Dorcus titanus mindanaoensis - Mindanao
• Dorcus titanus nobuyukii - Malaysia
• Dorcus titanus okinawanus - Okinawa
• Dorcus titanus okinoerabuensis
• Dorcus titanus palawanicus - Palawan Island
• Dorcus titanus pilifer - Japan
• Dorcus titanus platymelus - China
• Dorcus titanus sakishimanus - Sakishima Islands (サキシマヒラクワガタ/(in Japanese))
• Dorcus titanus sika - Taiwan (台灣扁鍬形蟲/(in Chinese))
• Dorcus titanus titanus - Indonesia
• Dorcus titanus takaraensis - Takara Islands
• Dorcus titanus tatsutai
• Dorcus titanus tokunoshimaensis
• Dorcus titanus typhon - the Philippines
• Dorcus titanus typhoniformis - Yunnan
• Dorcus titanus westermanni - India
• Dorcus titanus yasuokai - Sumatra

[2]

• Mizunuma T. & Nagai S. (1994) The Lucanid Beetles of the World. Mushi-Sha's Iconographic Series of Insects, Ed. H. Fujita, Japan. Vol. I
• Huang, H. & Chen, C.-C. 2013: Stag beetles of China Ⅱ

• Photos of Dorcus titanus daitoensis
• Photos of Dorcus titanus sika
• Photos of Dorcus titanus titanus