The family Scarabaeidae, as currently defined, consists of over 35,000 species of worldwide; they are often called scarabs or scarab beetles. The classification of this family has undergone significant change. Several groups formerly treated as subfamilies have been elevated to family rank (e.g., Bolboceratidae, Geotrupidae, Glaresidae, Glaphyridae, Hybosoridae, Ochodaeidae, and Pleocomidae), and some reduced to lower ranks. The subfamilies listed in this article are in accordance with those in Catalog of Life (2023).[
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Description
Scarabs are stout-bodied beetles; most are brown or black in colour, but many, generally species that are diurnally active, have bright metallic colours, measuring between . The antennae of most species superficially seem to be knobbed (capitate), but the several segments comprising the head of the antenna are, as a rule, lamellate: they extend laterally into plates called lamellae that they usually keep compressed into a ball. Then, when following a scent, such a beetle fans the lamellae out like leaves to sense odours.
Many species are fossorial, with legs adapted for digging. In some groups males (and sometimes females) have prominent horns on the head and/or Prothorax to fight over mates or resources.[Brett Ratcliffe, Dena M. Smith, Diane Marie Erwin. " Oryctoantiquus borealis, New Genus and Species from the Eocene of Oregon, U.S.A., the World's Oldest Fossil Dynastine and Largest Fossil Scarabaeid (Coleoptera: Scarabaeidae: Dynastinae)". 2009. The Coleopterists Bulletin 59(Mar 2005):127-135 DOI:10.1649/0010-065X(2005)0590127:OBNGAS2.0.CO;2]
The C-shaped , called grubs, are pale yellow or white. Most adult beetles are nocturnal, although the flower chafers (Cetoniinae) and many leaf chafers (Rutelinae) are active during the day. The grubs mostly live underground or under debris, so are not exposed to sunlight. Many scarabs are scavengers that recycle dung, carrion, or decaying plant material.
Some of the well-known beetles from the Scarabaeidae are Japanese beetles, , , rose chafers (Australian, Cetonia aurata, and North American), Dynastinae, and Goliathus.
Several members of this family have structurally coloured shells which act as left-handed circular polarisers; this was the first-discovered example of circular polarization in nature.
Ancient Egypt
In Ancient Egypt, the dung beetle now known as Scarabaeus sacer (formerly Ateuchus sacer) was revered as sacred.[ bugguide.net Family Scarabaeidae - Scarab Beetles]
See also
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Dung beetle – Scarabaeidae dung beetles play an important role in temperate and tropical environments
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List of Scarabaeidae genera
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List of Scarabaeidae subfamilies and tribes
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Scarab artifact
Further reading
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RU Ehlers. Current and Future Use of Nematodes in Biocontrol: Practice and Commercial Aspects with Regard to Regulatory Policy Issues. Biocontrol Science and Technology Volume 6, Issue 3, 1996.
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