Wikijunior:Bugs/Beetle

What does it look like?

A Hercules Beetle (left) and a Jade Headed Buffalo Beetle (right).

Beetles come in all shapes and sizes. Some are very large. Some are smaller than a grain of rice. The Goliath Beetle can be 4 or 5 inches long. A Bark Beetle is about 1/4 inch long.

Beetles have a hard, flexible cover called an exoskeleton. They have a head, mid-section (thorax), and abdomen. Thin front plates (elytra) protect the back wings. Beetles have large compound eyes and chewing mouthparts. Antennae may be threadlike or clubbed. Their strong jaws are called mandibles. Beetle bodies can be rounded or long and thin. Most are dull shades of brown or black. Some are shiny with bright rainbow colors. Some have dots and stripes.

Bark Beetles are brownish-black. Some beetles have spots that glow in the dark. The Eyed Beetle has two big spots that look like eyes on its back. Click Beetles are mostly black; some have patterns.

Hercules Beetles are greenish-gray with black blotches. They are about 2 to 2-1/2 inches long. Males are called Unicorn Beetles because they have a horn on the front of the head.

Lady Beetles have oval, dome-shaped bodies. They have short legs and antennae. They are brightly colored. Most have red-orange wing coverings and black spots or stripes. Some are yellow, pink, or brown. Others are black with red, orange, or yellow spots. Some have no markings at all.

Tiger Beetles are brownish-black or green. Many have patterns and bright colors. They have long slender legs.

Where does it live?

An Elephant Beetle feeding on a stalk of sugar cane.

Beetles can be found all over the earth in all kinds of habitats. They live in dark, moist places under logs, rocks, and leaves. They like gardens, grain fields, ponds and lakes. They have not been found in the frozen areas at the North and South Poles. Most species live on plants. Many tunnel, burrow, or swim.

Bark Beetles live on leaves and flowers, under bark, and in rotting wood. They are sometimes found in firewood. They hide in dark crevices of buildings. Hercules Beetles are found in tropical jungles and rainforests. They are common in Central and South America, Mexico, and southeastern United States. They range as far north as southern Ohio and Indiana. They are found in fallen debris and leaf litter on the forest floor.

Ladybird Beetles are found all over the world in gardens, farm fields, and meadows. They live in grasslands, forests, near rivers, and in cities. Lady Beetles are the official state insect of Delaware, Massachusetts, New Hampshire, New York, Ohio, and Tennessee.

Stag Beetles live in wooded areas and on beaches. Tiger Beetles like bright sunlight and open shade. They are found on sandy beaches and along paths and lanes.

What does it eat?

Beetles eat many things besides insects. Some beetles eat both plants and animals. Carnivorous beetles eat earthworms and snails.

A few beetles drink liquids from plants, trees, and fruits. Some can eat only one kind of plant. Bark Beetles eat the inner bark of trees like hickory, walnut, and Douglas fir. They destroy the tree’s food and water tubes that keep it alive.

Click Beetles feed on newly planted seeds. They eat the roots of vegetables, grains, and cotton. Their larvae feed on plants and vegetables.

Lady Beetles eat small insects like mealy bugs and mites. They are best known as aphid eaters. Some eat melons, potatoes, and beans.

Carrion Beetles eat dead animals. Clown Beetles eat the larvae of other insects. Diving Beatles eat tadpoles and other small water creatures.

How does it defend itself?

Beetles have various defense strategies. They use camouflage to blend into their surroundings to hide from predators. They mimic the color and shape of other insects to deceive enemies. Some are poisonous. They have large many-faceted compound eyes to detect small movements. Wing coverings (elytra) make a hard shield to protect the soft body and wings.

Click Beetles use a special body part that clicks and flips the beetle over in the air. The sound startles the predator so the beetle can escape.

Male Hercules Beetles use their long horns to fight other males. Many Longhorn Beetles look like wasps, even though they are harmless. Stag Beetles rear back and open their jaws wide to scare predators. Sometimes they play dead.

Ladybird Beetles fall to the ground and play dead. Their bright colors warn predators away. They secrete a bad tasting fluid from their leg joints. They cluster together in large numbers for protection when they hibernate. The cluster gives off a strong smell to repel predators.

What stages of metamorphosis does it go through?

A stag-beetle larva

Beetles undergo complete metamorphosis with 4 separate life stages: egg, larva (feeding stage), pupa (resting stage), and adult. Beetles mate in spring or summer. Females lay eggs in protected areas near a food source or inside a ball of food. Some beetles feed their young.

When the larvae hatch from the eggs they are wingless. Later, they enter the pupa or resting stage. Many spend the winter in the pupa stage. They change to adults during the pupa stage. They live about one year after becoming adults.

Ladybird Beetles complete their life cycle in about a month, depending on the weather. Some Lady Beetles live 2 or 3 years.

Bark Beetles chew under the bark to make tubes called galleries. They lay eggs along the sides of the galleries. When the eggs hatch, the larvae bore into the wood to make the galleries bigger. When it is full grown, the adult Bark Beetle bores a hole in the bark to emerge from the tree.

What special behavior does it exhibit?

Scarab Beetles push or roll balls of dung to their brood sites. It is thought that this behavior inspired the design in Egyptian art showing the Scarab Beetle pushing the sun across the sky.

Although most beetles have a hard time righting themselves when turned upside down, the Click Beetle does not. It has a special part on the underside of its body to flip it right side up.

Many beetles make noises by tapping on hard surfaces or by rubbing parts of the body together. These beetles seem to have better hearing than beetles that do not make such sounds.

Burying Beetles are known to hide small animal carcasses to feed their young. A small dead animal, such as a mouse, supplies food for a whole brood of larvae that a pair of beetles will care for together.

Horned Beetles are bred for fighting in some parts of the world.

An African Jewel Beetle.

How does it affect people?

Beetles are important waste recyclers. Many species decompose dead plants and animals and dung. Some beetles help farmers by eating insects that destroy trees and crops. Ladybird Beetles eat aphids and other harmful insects.

Some beetles are very serious pests that can transmit disease. Others cause millions of dollars in damage to plant products. Woodworm Beetles damage furniture and wood floors. Bark Beetles chew inside tree trunks to make tunnels. This opens up the tree to diseases. Bark Beetles have caused thousands of elm trees to die from Dutch Elm Disease.

Click Beetles eat newly planted seeds. They feed on roots of vegetables, grains, and cotton. Their larvae eat plants and vegetables. In the South, Mexican Bean Beetles and Squash Lady Beetles spoil crops.

References

Borror, D. J. & White, R. E. (1970). A field guide to insects of America north of Mexico. Houghton Mifflin Company.

Milne, L. & Milne, M. (2003). National Audubon Society field guide to North American insects and spiders. Alfred A. Knopf.

Thomas, J. (2001). Beetles. In Nature’s children. (Set 7). Grolier Educational.

Zim, H. S. (1987). Insects, A guide to familiar American insects. Golden Press, NY.

https://www.britannica.com/animal/bark-beetle

http://www.insected.arizona.edu/ladyinfo.htm

https://www.insectid.ento.vt.edu/insect-id/

https://www.kidsdiscover.com/quick-reads/34551/

https://www.natgeokids.com/uk/discover/animals/insects/ladybird-facts/