The family Scarabaeidae as presently 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, Bolboceratidae)
Scarabs are stout-bodied beetles, many with bright metallic colors, measuring between 5 and 60 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 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.
In ancient Egypt, scarabs were revered as sacred. Some of the well-known beetles from the Scarabaeidae are Japanese beetles, dung beetles, June beetles, rose chafers (European and North American), rhinoceros beetles, Hercules beetles and Goliath beetles.
Liparetrus species; subfamily Melolonthinae
Onthophagus species; subfamily Scarabaeinae
Punctate Flower Chafers (Polystigma punctata) mating
Adult Japanese beetle, (Popillia japonica).
Common June Beetle (Phyllophaga sp.) found in Michigan.
Ten-lined June beetle (Polyphylla decemlineata) found in the western United States.