Insecta

Predominant group of arthropods, placed within the class Hexapoda along with the Protura, Collembola, and Diplura. The only group other than vertebrates to have developed flight.

Order Archaeognatha (Jumping bristletails)
Order Monura - extinct
Order Thysanura (Common bristletails: silverfish, firebrats)
Pterygota, the winged insects
- Order Palaeodictyoptera - extinct
- ...
- Order Ephemeroptera (Mayflies)
- Order Odonata (Dragonflies and damselflies)
- Neoptera, insects with folding wings
  - Order Blattodea (Cockroaches)
  - Order Mantodea (Mantids)
  - Order Isoptera (Termites)
  - Order Zoraptera (Zorapterans)
  - Order Grylloblattodea (Ice Insects)
  - Order Dermaptera (Earwigs)
  - Order Plecoptera (Stoneflies)
  - Order Orthoptera (Grasshoppers, crickets, and katydids)
  - Order Phasmatodea (Walking sticks, timemas)
  - Order Embioptera (Webspinners)
  - Various extinct orders
  - Hemipterodea
    - Order Psocoptera (Booklice and barklice)
    - Order Pthiraptera (Sucking and chewing lice)
    - Order Hemiptera (True bugs, cicadas and kin - formerly Heteroptera + Homoptera)
    - Order Thysanoptera (Thrips)
  - Endopterygota, insects with complete metamorphosis
    - Order Miomoptera - extinct
    - Order Megaloptera (Alderflies, dobsonflies, and fishflies)
    - Order Raphidioptera (Snakeflies)
    - Order Neuroptera (Net-veined insects)
    - Order Coleoptera (Beetles)
    - Order Strepsiptera (Twisted-winged parasites)
    - Order Mecoptera (Scorpionflies and kin)
    - Order Siphonaptera (Fleas)
    - Order Diptera (Flies)
    - Order Trichoptera (Caddisflies)
    - Order Lepidoptera (Butterflies and moths)
    - Order Hymenoptera (Bees, ants, wasps, sawflies, and kin)

Let's not overlook the (genus?) Nupedia, a kind of fly! ;-)