ENTOMOLOGY
&
ECONOMIC
ZOOLOGY
Professor Academy
Introduction to
Entomology
Definition: Study of insects, their biology,
ecology, and role in the environment
Importance:
• Constitute over 75% of all known animal
species
• Play vital roles in pollination,
decomposition, pest control, and as
vectors of diseases
Branches of Entomology:
• Agricultural Entomology
• Medical Entomology
• Veterinary Entomology
Body Segmentation:
• Three main regions: Head, thorax, and
abdomen
• Exoskeleton: Composed of chitin
General Characteristics • Antennae: Sensory organs for smell and
of Insects touch
• Eyes: Compound eyes and simple eyes
(ocelli)
• Mouthparts: Adaptations for chewing,
piercing, sucking, or sponging
• Wings: Usually two pairs (exceptions exist)
• Legs: Three pairs, adapted for walking,
jumping, digging, or swimming
• Respiration: Through tracheal system
• Reproduction: Mostly oviparous, with distinct
metamorphosis (complete or incomplete)
Classification of
Insects
• Phylum: Arthropoda
• Class: Insecta
• Key Features of Class
Insecta:
• Body divided into head,
thorax, abdomen
• One pair of antennae
• Three pairs of jointed legs
Adaptations in
Insects
Mouthparts:
• Chewing (grasshopper)
• Piercing-sucking
(mosquito)
• Sponging (housefly)
• Siphoning (butterfly)
Wings:
• Membranous (dragonfly)
• Scaly (butterfly)
• Elytra (beetle)
Legs:
• Jumping (grasshopper)
• Swimming (water beetle)
• Grasping (praying mantis)
Key Orders & Economic Importance
Orthoptera: Hemiptera: Coleoptera:
• Agricultural pests (e.g., • Pests (e.g., aphids, • Pollinators (ladybirds).
locusts). mealybugs). • Pests (boll weevil).
• Vectors of plant
diseases.
Lepidoptera: Diptera: Hymenoptera:
• Silk producers • Disease vectors • Pollinators (bees).
(silkworm). (mosquitoes). • Biological pest control
• Pollinators. • Decomposers (parasitic wasps).
(houseflies).
Classification Up to
Order Level
• Apterygota (Wingless insects):
• Order Thysanura: Silverfish (Lepisma saccharina)
• Pterygota (Winged insects):
• Order Odonata: Dragonflies and damselflies (Anax)
• Order Orthoptera: Grasshoppers, crickets (Acrida)
• Order Hemiptera: True bugs, aphids (Cimex lectularius)
• Order Coleoptera: Beetles (Coccinella)
• Order Lepidoptera: Butterflies and moths (Danaus plexippus)
• Order Diptera: Flies and mosquitoes (Anopheles)
• Order Hymenoptera: Bees, ants, wasps (Apis mellifera)
• Order Isoptera: Termites (Odontotermes)
• Order Siphonaptera: Fleas (Xenopsylla cheopis)
ECONOMIC ZOOLOGY
Positive Roles
• Pollination (bees, butterflies)
• Silk production (silkworm)
Economic • Natural pest control (ladybirds)
Zoology • Decomposition (dung beetles)
& Negative Roles
Role of Insects • Pests of crops (locusts, aphids)
• Vectors of diseases (mosquitoes,
tsetse flies)
Conclusion
Key Takeaways:
• Diversity and adaptability of insects
• Their critical roles in ecosystems
and the economy
• Need for balanced pest
management and conservation
MCQ Time
1.What is the study of insects called?
a) Zoology
b) Botany
c) Entomology
d) Ecology
1.What is the study of insects called?
a) Zoology
b) Botany
c) Entomology
d) Ecology
2. Which substance forms the exoskeleton
of insects?
a) Cellulose
b) Chitin
c) Keratin
d) Protein
2. Which substance forms the exoskeleton
of insects?
a) Cellulose
b) Chitin
c) Keratin
d) Protein
3. Insects belong to which class?
a) Arachnida
b) Crustacea
c) Insecta
d) Myriapoda
3. Insects belong to which class?
a) Arachnida
b) Crustacea
c) Insecta
d) Myriapoda
4. Which order of insects includes butterflies
and moths?
a) Diptera
b) Coleoptera
c) Lepidoptera
d) Hymenoptera
4. Which order of insects includes butterflies
and moths?
a) Diptera
b) Coleoptera
c) Lepidoptera
d) Hymenoptera
5. What type of metamorphosis is characterized
by distinct stages: egg, larva, pupa, and adult?
a) Incomplete metamorphosis
b) No metamorphosis
c) Complete metamorphosis
d) Partial metamorphosis
5. What type of metamorphosis is characterized
by distinct stages: egg, larva, pupa, and adult?
a) Incomplete metamorphosis
b) No metamorphosis
c) Complete metamorphosis
d) Partial metamorphosis
ALL THE BEST
