Dynastinae

European rhinoceros beetle – three stages from larva to adult:
Larva (back), pupa (center), imago (front)

The Dynastinae are among the largest of beetles, reaching more than 15 cm (6 in) in length, but are completely harmless to humans because they cannot bite or sting. Some species have been anecdotally claimed to lift up to 850 times their own weight.[2] Their common names refer to the characteristic horns borne only by the males of most species in the group. Each has a horn on the head and another horn pointing forward from the center of the thorax. The horns are used in fighting other males during mating season, and for digging. The size of the horn is a good indicator of nutrition and physical health.[3]

The body of an adult rhinoceros beetle is covered by a thick exoskeleton. A pair of thick wings lie atop another set of membranous wings underneath, allowing the rhinoceros beetle to fly, although not very efficiently, owing to its large size. Their best protection from predators is their size and stature. Additionally, since they are nocturnal, they avoid many of their predators during the day. When the sun is out, they hide under logs or in vegetation to camouflage themselves from the few predators big enough to want to eat them. If rhinoceros beetles are disturbed, some can release very loud, hissing squeaks. The hissing squeaks are created by rubbing their abdomens against the ends of their wing covers. Rhinoceros beetles are relatively resilient; a healthy adult male can live up to 2–3 years. The females rarely live long after they mate.

These beetles' larval stages can be several years long. The larvae feed on rotten wood and the adults feed on nectar, plant sap and fruit. First, the larvae hatch from eggs and later develop into pupae before they reach adult status (see picture at left). The females lay 50 eggs on average. Contrary to what their size may imply, adult rhinoceros beetles do not eat large amounts, unlike their larvae, which eat a significant amount of rotting wood.

Male Japanese rhinoceros beetles, (Allomyrina dichotoma) fight to dominate sap sites. Males use their horns to pry rival males off the area, and gives them the chance to mate with the female. In this and other species that defend mating sites, larger males with larger horns mate more frequently, as they win more contests. Small males often avoid larger males and exhibit alternative strategies gain access to females.[4][5]

Eupatorus gracilicornis (Dynastini)

Pentodon idiota (Pentodontini)

Xylotrupes sp. - From Kerala, India

Xylotrupes sp. – From Kerala, India

Agaocephalini Burmeister, 1847 (disputed)

• Aegopsis
• Agaocephala

Cyclocephalini Laporte, 1840

• Cyclocephala

• Endrödi, S. (1985). The Dynastinae of the World. Series Entomologica. 28. Dr. W. Junk Publishers. ISBN 978-9061931386.
• Dechambre (R.-P.) & Lachaume (G.) The Beetles of the World, volume 27, The genus Oryctes (Dynastidae), Hillside Books, Canterbury
• Gutierrez, Eric et al. “Variation in an Extreme Weapon: Horn Performance Differences Across Rhinoceros Beetle (Trypoxylus Dichotomus) Populations.” Insects. 10.10 (2019): n. pag. Web.
• Goczał, Jakub, et al. “Intersexual and Intrasexual Patterns of Horn Size and Shape Variation in the European Rhinoceros Beetle: Quantifying the Shape of Weapons.” Biological Journal of the Linnean Society, vol. 127, no. 1, May 2019, pp. 34–43. EBSCOhost, doi:10.1093/biolinnean/blz026.

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• Family SCARABAEIDAE
• Subfamily Dynastinae