The family Scarabaeidae as currently defined consists of over 30,000 species of beetles worldwide. The species in this large family are often called scarabs or scarab beetles. The classification of this family is fairly unstable, with numerous competing theories, and new proposals appearing quite often. It is probable that many of the subfamilies listed here will no longer be recognized very much longer, as they will likely be reduced in status below subfamily rank, or elevated to family status (the latter is most likely, e.g., with the family "Melolonthidae" already appearing in some recent classifications). Other families have been removed recently, and are nearly universally accepted (e.g., Pleocomidae, Glaresidae, Glaphyridae, Ochodaeidae, Geotrupidae, and Bolboceratidae).

Scarabs

Scarabs are stout-bodied beetles, many with bright metallic colors, measuring between 1.5 and 160 mm. They have distinctive, clubbed antennae composed of plates called lamellae that can be compressed into a ball or fanned out like leaves to sense odors. The front legs of many species are broad and adapted for digging.

The C-shaped larvae, 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. Others, such as the Japanese beetle are devastating agricultural pests.

Some of the well-known beetles from the Scarabaeidae are Japanese beetles, dung beetles, June beetles, rose chafers (Australian, European and North American), rhinoceros beetles, Hercules beetles and Goliath beetles.

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.^[1]

White grub

White grubs, grubworms or curl grubs are the larvae of scarabs. Grubs commonly attack the roots of turfgrasses and ornamental plants. Damage first appears as drought stress, such as wilting and drooping.

Heavily infested turf first appears a gray-green off color and wilts in the hot sun. Such infestations typically appear in oddly shaped and sized patches among healthy plants, creating an unsightly contrast. Continued feeding will cause the turf to die in large irregular patches.

The tunneling nature of the grubs causes the turf to feel spongy, and it is easily rolled back, since the deep roots are consumed first, exacerbating the plants' problems with drought in hot dry weather. Grub populations also attract predatory mammals such as armadillos, skunks, raccoons, opossums, and moles that can hear the grub activity and dig into the turf in search of a meal - causing further damage to the turf.

Remedies

Until recently, the most common treatment in the United States was an application of an extermination chemical, such as diazinon. However, diazinon use has been discouraged by EPA in favor of chemical preservatives, which alter the taste of the roots and more specifically target grubs without affecting other insect species as does diazinon or other poisons.

Somewhat more natural pesticides, with fewer unwanted side effects, include milky spore disease (MSD or Bacillus popilliae Dutky) and beneficial nematodes (Heterorhabditis spp.).^[2]

Ancient Egypt

In ancient Egypt, a dung beetle now known as Scarabaeus sacer was revered as sacred.

In his 1859 book On the Origin of Species, Charles Darwin described the genus Ateuchus as the "sacred beetle of the Egyptians."^[3]

Gallery

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  Chiloloba acuta

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  Liparetrus species; subfamily Melolonthinae

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  Onthophagus species; subfamily Scarabaeinae

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  Punctate flower chafers (Polystigma punctata) mating

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  Phyllotocus sp.

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  Melolontha melolontha, the once common cockchafer or May bug

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  Adult Japanese beetle, (Popillia japonica)

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  Male Hercules beetle, Dynastes hercules (The green beetle in the background is a flower beetle, Eudicella gralli)

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  Common June beetle (Phyllophaga sp.) found in Michigan

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  Used in 19th century amateur art (Bankfield Museum)

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  Ten-lined June beetle (Polyphylla decemlineata) found in the western United States and Canada.

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  Rear view of Pachnoda sinuata

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  Gymnetis stellata

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  Cyprolais quadrimaculata

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  Cyriodera tuberculicollis

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  Dischista cincta

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  Male Milichus durandi

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  Pachylomera femoralis

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  Rhizotrogus punicus

See also

• Scarab artifact
• Grapevine beetle

References

Further reading

• 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.

The Trichiinae are a subfamily of the scarab beetle family (Scarabaeidae), but occasionally they are included in the Cetoniidae as tribe Trichiini. The conspicuous bee beetles (Trichius) are probably the best-known genus in Europe.

They vary in size from 6 to 65 mm [1] and can be distinguished from the Cetoniidae by having covered epimeres, and lateral edges of the elytra which are not trimmed.

The adults feed on sugar-rich secretions of stems, leaves, fruits and flowers of different plants. Most larvae develop in rotten wood.

Selected taxa

• Dialithus Parry, 1849
• Epitrichius
• Giesbertiolus Howden, 1988
• Gnorimella
• Gnorimus Le Peletier & Serville, 1828
  • Gnorimus nobilis – Noble Chafer
• Inca
• Lasiotrichius
• Osmoderma
• Paratrichius
• Platygeniops Krikken, 1978
• Trichiotinus
  • Trichiotinus piger – Hairy Flower Chafer, Bee-like Flower Scarab
• Trichius – bee beetles
• Trigonopeltastes