| Group | Approximate number of described living species |
|---|---|
| Jumping bristletails (Archaeognatha) | 550 |
| Silverfish (Zygentoma) | 575 |
| PTERYGOTE (WINGED) INSECTS (PTERYGOTA) | |
| Mayflies (Ephemeroptera) | 3,250 |
| Dragonflies and damselflies (Odonata) | 6,000 |
| Neopterans (Neoptera)b | |
| Ic | 35 |
| Gladiators (Mantophasmatodea) | 15 |
| Stoneflies (Plecoptera) | 3,800 |
| Webspinners (Embioptera) | 500 |
| Angel insects (Zoraptera) | 40 |
| Earwigs (Dermaptera) | 2,000 |
| Grasshoppers and crickets (Orthoptera) | 24,000 |
| Stick insects (Phasmida) | 3,000 |
| Cockroaches (Blattodea) | 4,500 |
| Termites (Isoptera) | 3,000 |
| Mantids (Mantodea) | 2,500 |
| Booklice and barklice (Psocoptera) | 5,750 |
| Thrips (Thysanoptera) | 6,000 |
| Lice (Phthiraptera) | 5,000 |
| True bugs, cicadas, aphids, leafhoppers (Hemiptera) | 104,000 |
| Holometabolous neopterans (Holometabola)c | |
| Ants, bees, wasps, sawflies (Hymenoptera) | 150,000 |
| Beetles (Coleoptera) | 390,000 |
| Strepsipterans (Strepsiptera) | 650 |
| Lacewings, ant lions, mantidflies (Neuroptera) | 6,000 |
| Dobsonflies, alderflies, fishflies (Megaloptera) | 350 |
| Snakeflies (Raphidoptera) | 250 |
| Scorpionflies (Mecoptera) | 800 |
| Fleas (Siphonaptera) | 2,000 |
| True flies (Diptera) | 125,000 |
| Caddisflies (Trichoptera) | 12,000 |
| Butterflies and moths (Lepidoptera) | 180,000 |
aThe hexapod relatives of insects include the springtails (Collembola; 3,000 spp.), tw bNeopteran insects can tuck their wings close to their bodies. cHolometabolous insects are neopterans that undergo complete metamorphosis. | |