Beetle-mania.Beetles are the largest group in theAnimal Kingdom, representing about a fourth of all animals. Currently, more than 350,000 beetlespecieshave been identified. Yet scientists who study beetles (coleopterists) are certain there are thousands more that have not been discovered yet!
You may be familiar with some of the many different beetles by their common names: ladybugs, June bugs, weevils, lightning bugs or fireflies, borers, and potato bugs. No othergroup has such a range of color, shape, and size. Some beetles are as large as your fist; others are so small they can fit through the eye of a needle. Many are brilliantly colored, like jewels, while others cleverly blend into their environment.
Beetle body parts.The body of the beetle consists of three main segments: head, thorax, and abdomen.
Head—The head is where the beetle's eyes, mouth, brain, and antennae are found. Some horned beetles have extensions on their head that remind scientists ofhornsorantlers.
Thorax—The thorax is the powerhouse of the beetle body, divided into three parts. The beetle's six legs and its wings are attached to these parts. Thick, hardened front wings, called elytra, cover most of the beetle's body and its back wings offer great protection. Someare able to trap moisture under their wings, helping them survive in deserts where water is scarce. Otherscan live underwater because they are able to trap air under the elytra.
Abdomen—The abdomen contains the organs for digestion and reproduction. A toughexoskeletonand the elytra protect the beetle's soft membranes and keep the beetle from drying out or getting waterlogged.
Flexible, long antennae on the beetle's head act like feelers to help the beetle find food, a mate, and places to lay eggs. They also alert the beetle to vibrations in the air that could mean apredatoris near. A beetle uses its legs to regularly clean those important antennae. Tiny hairs on its body and legs, called setae, are sensitive to touch, sound, smell, taste, and light.
Most beetles have compound eyes (eyes that are divided into many six-sided compartments). Compound eyes are very sensitive to movement and can probably see in color. Beetles that rely on vision for hunting (ground beetles) or breeding (fireflies, Lampyridae family) have larger eyes. Whirligig beetles (Gyrinidae family), which swim on the surface of ponds, have divided eyes: one half for vision under water, the other for seeing above the water so they can find food that drops in or floats by.
Most beetles can fly, although they do so in a slow, clumsy manner. Water beetles are good swimmers, and many can fly as well. Some beetles that live in deserts have lost the ability to fly.
All beetles have jointed legs, but leg shape and size varies, depending on the beetle's lifestyle. For example, long and slender legs are made for speed (ground beetles, Carabidae family); broad and ridged legs are for digging (dung beetles, Scarabaeidae family); legs curved and shaped like a paddle are for swimming (water beetles, Hydrophilidae family); and large hind legs are for hopping (flea beetles, Chrysomelidae family). Some even have a sticky pad on the bottom of each foot to help them walk up slippery surfaces. All beetleshave a pair of claws on each foot. Many beetles need the sun to warm their bodies before they can run or fly quickly.
Stay safe! Beetles have a lot of different ways to protect themselves from becoming someone else's lunch. The hard, shiny elytra is often enough to keep a beetle safe from other insects, or other beetles! Dome-shaped leaf beetles (Coccinelidae family) and ladybird beetles (Chrysomelidae family) pull their legs and antennae under this "shell," just like a turtle does. Some ladybird beetles release sticky yellow blood from their legs to gum up the antennae and mouthparts of the attacker.
Flightless ground beetles squirt out jets of formic acid, which burns the skin and causes eye damage. Leaf beetle larvae are so poisonous that people of the Kalahari Desert use them to tip their hunting arrows. Brightly colored or patterned beetles usually taste very bad to predators. Andcamouflageworks great for beetles living under rocks or bark, or in the soil.
