Scarabs are a mesmerizingly diverse family of beetle found in every part of the world except in the oceans and on Antarctica. There are about 30,000 scarab species comprising about 10 percent of all known beetles.
Differences Between Species
The June bug pinging incessantly off your front porch light is a type of scarab. The Japanese beetle that savages your landscaping? A scarab as well. The enormous rhinoceros beetles of Central and South America are scarabs. And perhaps the most famous member of the family, the sacred scarab, was actually worshipped by the Egyptians as the embodiment of the sun god Khepri.
Most scarabs are monotone black or brown in color. But many, particularly tropical varieties, explode with bright colors and intricate patterns. There are even species that are iridescent and some with a truly unnatural-looking metallic sheen.
Scarabs are generally oval-shaped and stout, ranging in size from miniscule to mythic. The smallest grow to about 0.08 inches (0.2 centimeters) while the Hercules beetle can reach a palm-covering 6.7 inches (17 centimeters) in length.
A Diet of Dung
Diets of these beetles vary from species to species. Some consume live plants and are considered agricultural pests. Some eat fruit, fungi, carrion, or insects. There’s even a variety that subsists on the slime left by snails.
But the most well-known diet item is consumed by the scarabs called dung beetles. These beetles subsist entirely on the undigested nutrients in the waste of herbivores like sheep, cattle, and elephants. The Egyptian sacred scarab is a dung beetle.
Dung beetles have a keen sense of smell that allows them to hone in on their favorite food and use specialized mouth parts to draw out moisture and nutrients from the waste. Some species simply live in the dung, while others form perfectly spherical dung balls, which they roll with their hind legs, often over large distances, to a place where they can bury it. Females plant a single egg in a dung ball where it matures from larva to fully formed beetle, feeding off the waste. Because they move so much waste underground, dung beetles are considered essential to controlling disease and pests among livestock.
Some species of scarab are threatened by habitat loss and collection by beetle hunters, but as a whole, the scarab population is stable.