Some beetles can walk on land or fly in the air.
Others spend most of their time swimming in water. Some beetles are a big help
to farmers. Others are pests that destroy farm crops. Beetles live everywhere
on Earth except in the oceans and near the North and South poles.
Beetles are among the most common insects in the
world. In fact, scientists have found about 350,000 different species (kinds)
of these strange and interesting creatures.
WHAT DO BEETLES LOOK LIKE?
Beetles come in many shapes, colors, and
sizes. Some are round. Others are long and thin. Most are brown or black. Some
beetles have bright, shiny bodies. Many have colored spots or stripes. Jewel
beetles can be blue, black, green, or copper colored. Ladybird beetles, also
called ladybugs, are orange with black dots.
Most beetles are smaller than your thumb. The
world’s largest beetle is the giant longhorned beetle of South America. It can
grow to more than 7 inches (18 centimeters) in length. The tiny feather-winged
beetle of North America is one of the world’s smallest insects. It could fit on
the head of a pin!
Some beetles have horns. Rhinoceros beetles have
two big horns. Longhorned beetles have long, curving antennae, or
feelers, that look like horns. Weevils are beetles with long, slender snouts. A
beetle’s jaws are called mandibles. Some beetles, such as male stag
beetles, have large, powerful mandibles that look like deer antlers.
BODIES OF BEETLES
Beetles, like all insects, have a body with three
main parts: head, thorax, and abdomen. A beetle has antennae, eyes, and
mouthparts on its head. It has six legs and two pairs of wings—front wings and
hind wings—on its thorax. A beetle digests food in its abdomen.
Beetle wings are special. The front set of wings is
hard. These wings are called elytra. The colors of a beetle are on its
elytra. The hard elytra cover and protect the delicate hind wings. Beetles use
only their hind wings for flight. To take off, a beetle spreads open its elytra
and then unfolds its hind wings.
Beetles, like other insects, do not have bones.
Instead, they have a hard covering called an exoskeleton on the outside
of their bodies. The covering is like armor that protects their insides. The
covering of a beetle is harder than the covering of most other insects.
Some beetles that fall over on their hard backs
have trouble standing up. They just lie helplessly on their backs waving their
legs. One exception is the click beetle, which can jump into the air and land
right side up. It makes a clicking sound during its jump.
WHAT HAPPENS AS A BEETLE GROWS?
When a beetle grows bigger, it has to shed
(get rid of) its hard covering. This shedding is called molting. Every
time a beetle molts, it grows a new, bigger hard covering.
FOUR LIFE STAGES
A beetle has four stages in its life. It
starts out as an egg. Some adult female beetles lay one egg. Others lay many
eggs. The egg hatches into a larva that looks like a worm.
Beetle larvae are called grubs. Grubs may eat
living plants, other insects, or dead plants and animals. When the larva is
full grown, it spins a cocoon called a pupa around itself. While inside
the cocoon, the larva grows into an adult beetle.