Hexapoda

Hexapoda includes all six legged Arthropoda (animals with exoskeletons). Hexapoda are artificially divided into soft bodied Entognatha (having mouthparts that retracted within the head) and Insecta (that is Ectognatha having unretractable mouthparts).

Kingdom: Animalia

Phylum: Arthropoda

Subphylum: Hexapoda

Class: Entognatha (over 5000 known species)

Order: Collembola (springtails, ca. 8,163 species)

Order:  Protura (“first-tail”, ca. 816 species)

Order: Diplura (“two-tail”, ca. 975 species)

Class: Insecta

Subclass: Monocondylia

Order: Archaeognatha (jumping bristletails, ca. 506 species)

(unranked): Dicondylia

Order: Zygentoma (silverfish, ca. 554 species)

Subclass: Pterygota (winged insects, ca. 1.5 million named species; potentially, 10 million species overall)

The Pterygota are divided into two Infraclasses: 

Infraclass Palaeoptera 

Order: Ephemeroptera (mayflies, ca. 3,124 species)

Order: Odonata (dragonflies and damselflies, ca. 6,042 species)

Infraclass: Neoptera

Superorder: Exopterygota (immature stages resemble adults; externally developing wings)

Superorder: Endopterygota (life cycle goes through distinctive larval, pupal, and adult stages; internally developing wings)

Superorder: Exopterygota

Order: Blattodea (cockroaches & termites*, ca. 7,750 species)

              * previously a separate order Isoptera.

Order: Mantodea (mantids, ca. 2,425 species)

Order: Dermaptera (earwigs, ca. 1,933 species)

Order: Plecoptera (stoneflies, ca. 3,713 species)

Order: Orthoptera (grasshoppers, crickets etc, ca. 23,830 species )

Order: Phasmatodea (stick & leaf insects, ca. 3,046 species)

Order: Embioptera (webspinners, ca 457 species)

Order: Zoraptera (angel insects, ca. 36 species)

Order: Notoptera

              suborder: Grylloblattodea (ice-crawlers,  32 species)

             suborder:  Mantophasmatodea (gladiators, 17 species)

Order: Psocoptera (booklice, barklice, ca. 5,611 species)

Order: Thysanoptera (thrips, ca. 5,938 species)

Order: Phthiraptera (lice, ca. 5,135 species)

Order: Hemiptera (true bugs, ca. 102,183 species)

Superorder: Endopterygota

Order:  Hymenoptera (ants, bees, etc., ca. 153,088 species)

Order:  Coleoptera (beetles, ca. 389,487 species)

Order:  Strepsiptera (twisted-winged parasites, ca. 633 species)

Order:  Raphidioptera (snakeflies, ca. 184 species)

Order:  Megaloptera (alderflies, ca. 359 species)

Order:  Neuroptera (net-veined insects, ca. 5,468 species)

Order:  Mecoptera (scorpionflies & fleas**, ca. 2,482 species)

              **previously a separate order Siphonaptera

Order:  Diptera (true flies, 156,774 species)

Order:  Trichoptera (caddisflies, ca. 14,548 species)

Order:  Lepidoptera (butterflies, moths, ca. 158,423 species)

This classification is simplified in that it only includes currently extant organisms, while it excludes extinct organisms. The estimates of numbers of species are provisional, because these numbers are progressively increasing as new species are described.

Species estimates from:

Zhang, Z. Q. (2013). Phylum Arthropoda. In: Zhang, Z.-Q.(Ed.) Animal Biodiversity: An Outline of Higher-level Classification and Survey of Taxonomic Richness (Addenda 2013). Zootaxa, 3703(1), 17-26.