Insects (from Latin insectum, a calque of Greek ἔντομον [éntomon], “cut into sections”) are a class within the arthropods that have a chitinous exoskeleton, a three-part body (head, thorax, and abdomen), three pairs of jointed legs, compound eyes, and two antennae. They are among the most diverse group of animals on the planet and include more than a million described species and represent more than half of all known living organisms. The number of extant species is estimated at between six and ten million, and potentially represent over 90% of the differing metazoan life forms on Earth. Insects may be found in nearly all environments, although only a small number of species occur in the oceans, a habitat dominated by another arthropod group, the crustaceans.
Anoplura – Sucking Lice
Coleoptera – Beetles
Dermaptera – Earwigs
Dictyoptera – Mantids and Cockroaches
Diptera – Flies
Embiidina – Webspinners
Ephemeroptera – Mayflies
Hymenoptera – Ants, Bees, Wasps and Sawflies
Hemiptera – True Bugs, Cicadas, Hoppers, Aphids and Allies
Isoptera – Termites
Lepidoptera – Butterflies and Moths
Mallophaga – Chewing Lice
Mecoptera – Scorpionflies, Hangingflies and Allies
Megaloptera – Alderflies, Dobsonflies, and Fishflies