1. Entomology is the study of insects and their relationships with humans, other insects, and the environment. 2. Insects belong to the phylum Arthropoda and class Insecta. They have three body regions, three pairs of legs, one pair of antennae, and typically have a hard exoskeleton and undergo either incomplete or complete metamorphosis. 3. Insects are classified into winged and wingless groups. Winged insects undergo complete metamorphosis from egg to larva to pupa to adult, while wingless insects have an incomplete metamorphosis from egg to nymph to adult.

2. Introduction to
Entomology

3. William Kirby is called the father of entomology
Entomology is the branch of zoology, which is mainly involved with
studying insects, their characteristics, general anatomy, morphology and
their contributions to biological diversity and a variety of other fields of
science.
It is a science which deals with study of insects and their relationship
with humans, other insects and environment
Study of economically important insects in agriculture is called
Agricultural Entomology

4. Entomology is derived from the Greek word
Entomon
(Insect)
Logos
(Study)
Insect is derived from Latin word
Insectum (cut into)

5. Taxis- order
Nomos- law
Branch of science concerned with
classification

7. Domain - Eukarya
Kingdom - Animalia
Phylum - Arthropoda
Class - Insecta

9. Arthro- joint
Poda- legs
The organisms with jointed appendages are kept under this
phylum arthropoda and they live in diverse environmental
habitats like fresh water ponds, seas and terrestrial.
Arthropoda :

10. Important features of Arthropoda
• Bilateral symmetry
• Haemocoelic body cavity
• Segmented body
• Paired jointed appendages
usually terminates with claws
• Chitinous exoskeleton
• Ventral nervous system
• Grow by moulting
• Muscles are composted of
striated fibres
• Ciliated epithelium absent
• Open circulatory system
• Heart is on dorsal side
• Alimentary canal is tubular with
mouth at anterior end and anus
at posterior end

11. Phylum Arthropoda is classified into 7 classes
Insecta (Hexapoda)
Onychophora
Chilopda
Diplopoda
Crustacea
Symphyla
Arachnida

12. Onychophora
Crustacea
 Prawns
 crabs
 lobsters

13. Arachnida
• Ticks
• Mites
• Scorpions
• Spider

14. Chilopda Diplopoda
Millipedes
Centipedes
Symphyla
Garden centipedes

15. Insecta (Hexapoda)

16. Insecta (Hexapoda)
Hexapoda: Hexa (six)
Poda (legs)
Sub-phylum: Mandibulate
Insects are tracheate arthropods whose body is
divided into three regions
 2 pair of wings, 3 pair of legs in thoracic
region
 Genital organs towards posterior end of the
body
 Decentralized nervous system

17. Characters of class insecta
1.Body is divided into head,
thorax and abdomen
2.Possess three pairs of legs
(hexapoda)
3.A pair of antennae
4.Presence of one or two
pair of wings

18. 5. Possess exoskeleton made up of hard cuticle which plays important role
for survival

19. 6. Respiration by means of tubes known as trachea

20. 7. Possess open circulatory system and body cavity is haemocoel

21. 8. Genital opening situated at posterior end of the body

22. 9. Presence of metamorphosis (incomplete/ complete) during development

23. 10. Excretion is mainly by
Malpighian tubules

24. 11. Sensory organs are distributed in different parts of the body

25. 1. Body is divided into head, thorax and abdomen
2. Possess three pairs of legs (hexapoda)
3. A pair of antennae
4. Presence of one or two pair of wings
5. Possess exoskeleton made up of hard cuticle which plays important role for survival
6. Respiration by means of tubes known as trachea
7. Possess open circulatory system and body cavity is haemocoel
8. Genital opening situated at posterior end of the body
9. Presence of metamorphosis (incomplete/ complete) during development
10.Excretion is mainly by Malpighian tubules
11.Sensory organs are distributed in different parts of the body
Characters of class insecta

26. Classification of class Insecta
Sl.
No.
Apterygota Pterygota
1. Wingless insects Winged insects
2. Metamorphosis is absent Metamorphosis is present
3. Mandibles are monocondylic Mandibles are dicondylic
4. Pregenital abdominal appendages are
present
Pregenital abdominal appendages are
absent
Ex: Silver Fish Ex: Grasshopper, Butterfly

27. Sub class: Apterygota
Protura Diplura Collembola Thysanura

28. Sub class: Pterygota
( 2 divisions)
Sl.no. Exopterygota Endoterygota
1. Wings are developed outside to the
body
Wings are developed inside to the body
2. Immature stages (nymph) resembles
adult
Immature stages (larva) do not resembles
adult
3. Metamorphosis is incomplete Metamorphosis is complete
4. Pupal stage is absent Pupal stage is present
Ex: Preying mantid Ex: Housefly

29. Division: Exopterygota
Nymph
Adult
Egg
Division: Endopterygota
larva
pupa
Adult
Egg

31. Larva
Lepidopterans :Caterpillar
Coleopetera & Hymenoptera :Grub
Diptera :Maggot

32. TYPES OF PUPA

33. Chrysalis Coarctate