What is an insect? It has three body parts, six legs and the adults have wings. Insects are a huge group, so scientists divide insects into smaller groups called orders. Bees and wasps and ants all belong to the order Hymenoptera. Butterflies and moths are together in another order called Lepidoptera. Bugs have their own order and so do beetles.
Bugs and beetles look a lot alike but there are some important differences. Bugs have long pointed, straw-like mouth parts for sucking up their food. Beetles have chewing mouthparts that move side to side like pincers to snip off food.
Adult bugs and beetles both have two sets of wings, but the first pair is not like the second pair. Bugs have two sets of wings, but the first pair is half leathery and half see through. The second pair is all see through. Your can see the leathery half of their wing when you look down at the top of the bug's back. Bugs look like they have an X on their back.
Beetles have two sets of wings, but the first pair is hard. It is called elytra. It acts like a cover for the second pair. The elytra aren't used for flying at all. When beetles fly, they lift up their elytra and unfold their second pair of wings. This is their flying wings. Sometimes the elytra have beautiful color patterns. The elytra are colored to help the beetle blend into its surroundings. These colors are all made of pigments, almost like paint. Some beetles have iridescent colors. Iridescent colors are not pigments at all. They are actually made with tiny grooves and edges perfectly spaced to reflect the light in a certain way. That's why iridescent colors seem to change when you view them at different angles. The elytra not only cover and protect the flying wings, they also help protect the beetle itself.
Some beetles have hard slippery elytra, so hard and slippery that birds can't grab them in their beaks without losing their grip. Click beetles have another trick. They have a hinge between their head and their thorax with a little knob. They can flex their muscles and make the hinge snap their bodies.
Some beetles like to give the birds the stink treatment so the birds will leave them alone. Darkling beetles put their abdomens up high as though they want to stand on their heads. When another animal tries to eat them, they make a nasty stink so the predator will avoid them.
A lot of beetles eat dead plants or dead animals. Some kinds even eat dung. But some types of beetles eat living plants, and some are little predators and go out hunting for prey
What do you think ladybird beetles eat? These beetles eat aphids. Some people call ladybird beetles . . . . ladybugs. But are they bugs, or are they beetles? Do they have elytra or a half leathery wing?
What about baby beetles? How do they start out?
Beetles start with:
- Eggs
- Larvae that look different than the adult.
- The larvae grow and molt.
When the larvae is big enough, it stops eating and makes a chrysalis
where it changes it's shape and becomes a beetle with elytra and
wings. This is complete metamophosis.
Bugs start with:
- Eggs
- Larvae that look a lot like the adult.
- The larvae grow and molt.
They start with tiny little wing buds. After each molt, the wing
buds grow.
Eventually the growing larvae with wing buds (a nymph) grows into
an adult with real wings. This gradual change is called incomplete
metamorphosis.
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