Invertebrate Zoology/Insects

Chapter 15 ~ The Arthropods
Class Insecta

Contents ~ Introduction ~ Protozoans ~ Metazoans ~ Sponges ~ Cnidaria
Ctenophores ~ Flatworms ~ Nemerteans ~ Pseudocoelomates ~ Annelids ~ Mollusks
Arthropods ~ Chelicerates ~ Crustaceans ~ Insects ~ Echinoderms

Insect larva ~ Barnacle ~ Long-jawed spider
The insects are a diverse group. Shown: moth larva, Marsh fly, and damselfly.

Phylum Arthropoda
Subphylum: Hexapoda
Class: Insecta

Subclass Apterygota

  • Symphypleona - globular springtails

Subclass Archaeognatha (jumping bristletails)
Subclass Dicondylia

  • Monura - extinct
  • Thysanura (common bristletails)

Subclass Pterygota

Introduction to the Insects


In terms of number of species described, the Subphylum Hexapoda is the largest in the Phylum Arthropoda. Hexapods (meaning "six legs or feet") include the insects (Class Insecta), which dominate terrestrial environments on earth. The subphylum also includes several groups of wingless arthropods of uncertain placement; namely the orders: Diplura, Collembola, and Protura.