Palaeodictyoptera - extinct
Ephemeroptera (mayflies)
Odonata (dragonflies and damselflies)
Infraclass Neoptera
Blattodea (cockroaches)
Mantodea (mantids)
Isoptera (termites)
Zoraptera
Grylloblattodea (rock crawlers)
Dermaptera (earwigs)
Plecoptera (stoneflies)
Orthoptera (grasshoppers, crickets, katydids)
Phasmatodea (walking sticks, timemas)
Embioptera (webspinners)
Mantophasmatodea (gladiators)
Superorder Hemipterodea
Psocoptera (booklice, barklice)
Phthiraptera (lice)
Hemiptera (true bugs)
Thysanoptera (thrips)
Superorder Endopterygota
Miomoptera - extinct
Megaloptera (alderflies, etc.)
Raphidioptera (snakeflies)
Neuroptera (net-veined insects)
Coleoptera (beetles)
Strepsiptera (twisted-winged parasites)
Mecoptera (scorpionflies, etc.)
Siphonaptera (fleas)
Protodiptera extinct
Diptera (true flies)
Trichoptera (caddisflies)
Lepidoptera (butterflies, moths)
Hymenoptera (ants, bees, wasps, etc.)
Pterygota is a subclass of insects that includes the winged insects. It also includes insect orders that are secondarily wingless (that is, insect groups whose ancestors once had wings but that have lost them as a result of subsequent evolution).
The living insect within the pterygotan group include almost all insects. The hexapod orders not included are the Microcoryphia (jumping bristletails) and the Thysanura (silverfishes and firebrats ), and two primitively wingless insect orders. Also not included are the three orders that are no longer considered to be insects: Protura, Collembola, and Diplura.