What are the differences between bugs and beetles?

Bugs and beetles may look similar at first glance, but they belong to two quite different insect groups.

Mouthparts

• Bugs: mouthparts modified into piercing stylet (i.e. needle-like).
• Beetles: chewing mouthparts.

Wings

• Bugs: wings (if present) are membranous or partially thickened.
• Beetles: forewings modified to form hard, leathery coverings called elytra, hindwings membranous and fold under elytra when not flying.

Diet

• Bugs: liquid diet: mostly plant-feeders (nectar/sap), some feeders on animal fluids.
• Beetles: wide range of plant and animal materials eaten.

Lifecycle

• Bugs: incomplete metamorphosis - juveniles resemble adults except smaller and lack wings.
• Beetles: complete metamorphosis - larvae with hardened head, chewing mouthparts and usually have legs.

Scientific classification

• Bugs: Order Hemiptera
• Beetles: Order Coleoptera