Insects




Insects come in many shapes and sizes, but their main characteristics are:

  • three main body parts – head, thorax, abdomen.
  • three pairs of legs – 6 total.
  • one pair of antennae.
  • a hard exoskeleton.





Almost all insects undergo some form of metamorphosis – a transformation from an immature life stage to an adult form. Some insects even migrate during their life cycle.

Apterygota – Wingless primitive insects

three long caudal tail filaments
no wings
no metamorphosis
Zygentoma(formerly Thysanura) – silverfish



Pterygota – Winged insects


Palaeoptera – Non-folded Wing
incomplete metamorphosis
nymphs/naiads look like small wingless adults
Odonata – Dragonflies & Damselflies
Ephemeroptera – Mayflies
    Neoptera – Folded Wing
Hemipteroid Assemblage
gradual or simple metamorphosis
lack cerci
have mouthparts for sucking
Psocodea – lice & booklice
Thysanoptera – thrips
Hemiptera – true bugs

Endopterygota
complete metamorphosis
wings develop during pupal stage
no food is consumed during pupal stage
Lepidoptera – butterflies, moths
 Neuroptera – lacewings, antlions
Hymenoptera – wasps, ants, bees
 Coleoptera – beetles
 Diptera – flies
 Megaloptera – alderflies, dobsonflies
 Raphidioptera – snakeflies
 Strepsiptera– twisted-wing parasites
 Mecoptera – scorpionflies, hangingflies
 Siphonaptera – fleas
 Trichoptera – caddisflies
 Paraplecoptera
Plecoptera – stoneflies
 Protoperlaria
 Embiidina – web-spinners
 Phasmida – stick & leaf insects
 Orthoptera – grasshoppers, crickets
 Mantophasmatodea – gladiators
 Zoraptera
 Dictyoptera – cockroaches, termites
 Dermaptera – earwigs
 Protelytroptera
 Grylloblattodea – ice bugs, rock crawlers
 Titanoptera