Fundamentals of Entomology

INTRODUCTION TO CLASS INSECTA

Character	Crustacea	Arachnida	Chilopoda	Diplopoda	Onychopoda	Insecta
Habitat	Aquatic and terrestrial	Terrestrial	Terrestrial	Terrestrial	Terrestrial	Many terrestrial and few aquatic
Body regions	Two – cephalothorax and abdomen	Three- Pro, meso and meta soma	Two- head and multi segmented trunk	Two- head and multi segmented trunk	Worm like- unsegmented in adults	Three: Head, thorax and abdomen
Antennae	Two pair	No antenna	One pair	One pair	One pair	One pair
Visual organs	One pair of stalked compound eyes	One pair of simple eyes	One pair of simple eyes	One pair of simple eyes	Simple eyes	Both simple (3 no.) and two compound eyes
Locomotor organs	Five pairs of biramous legs	Four pairs	One pair/segment	Two pairs/ segment	Many bilateral lobe like legs	3 pairs of legs on 3 thoracic segments and 2 pair of wings on meso and meta thorax
Respiration	Gill breathing	Book lungs tracheal	Tracheal	Tracheal	Tracheal	Tracheal
Habit	Herbivores, carnivores	Phytophagous and predators	Carnivorous	Herbivorous	Organic matter	Phytophagous, predators and parasitoids
Examples	Crayfish, crabs, wood lice and lobster	Spiders, scorpions, mites and ticks	Centipedes	Millipedes	Peripatus sp.	Insects

Animation of Insect cuticle

Insect life cycle