Fundamental of entomology Dr.Sunil Prajapati

Mangalayatan University,
Jabalpur
Department of Agriculture
Dr. Sunil Prajapati
Assistant Professor (Horticulture)

B.Sc.(Hon.)Agriculture
1st Year Semester II
FUNDAMENTALS OF ENTOMOLOGY 4(3+1)
 Introduction
 Branches of Entomology
 History of Entomology
 Contribution of Scientists
 Institutes /Organization n
 Classification of Phylum Arthropoda
 Characteristics of Arthropoda
 Insect Orders
 Classification of Insects
 Economic Importance of Insects
 Metamorphosis In Insects
 Types of Larvae
 Mouth Parts of an Insects
 Modification of Mouth Parts of an Insects
 Damaging Stages of Insects
 Modification of Insects Legs
 Structure and Function of Antennae
 Modifications of Insect Antennae.
Dr. Sunil Prajapati
Assistant Professor (Horticulture)

Entomology- Greek word (Entomon = Insect;
Logos = Study) It is the branch of zoology or
biological science that deals with the study of
insects.
INTRODUCTION
Insect:- The insects are the tracheate
arthropods in which the body is divided in
to head, thorax and abdomen possessing
• 2 pairs of wings.
• 3 pairs of working legs.
• 1 pair of antennae.
• Segmented body.
• Having complete and incomplete
metamorphosis.

• Insect is Greek word = Cut in pieces or
segmented.
• Insects belong to the Phylum Arthropoda
(Artho= jointed, Poda= Legs) which is the
biggest phylum of kingdom Animalia. More
than three quarters of the animals on earth
are arthropods, and most of these are
insects.
• Kingdom Animalia is classified into twelve
phyla.
INTRODUCTION

A pest is a small destructive organism (causes economic loss) that
usually attack crops, animals and food. Common examples of pests
include insect, weeds, cockroaches, mites, ticks, mosquitoes,
bed bugs, lice, nematodes, plants, birds, thrips, fungi, bacteria,
virus, rodents and termites are included.
Losses
Weeds (33%)
Diseases (26%)
Insects (20%)
Rodents (6-8%)
Birds (1-2%)
Others (1-3%)

• Study and use of insects in crime
investigations is known as Forensic
Entomology.
• Study of insects related to live stock
and veterinary animals is known as
Veterinary Entomology.
• Study of insects in relation to Human
beings is known as Medical
Entomology.
Branches of Entomology

• Mahabharta: (1424-1366 BC) Mentions about silk,
honey and lac.
• The famous story of ‘Lakshgruha’ i.e. House of lac
build by Kauravas to burn their cousins live,
Pandavas.
• Amarkosha Sanskrit dictionary provide references
like Patanga and Bhramar of flies, moths, beetles
and glow worms.
• Sushruta: Surgeon (100-200 AD): Classified ants
(Pipilika), mosquitoes and flies.
• Umaswati: Physician(0-100 AD): Classified the
bees.
History of Entomology

• Aristotle (384-322 B.C.)– Father of biological classification.
First person grouped insects in winged and wing less groups.
He gave the terms like Coleoptera and Diptera.
• Carolus Linnaeus (1758)– Father of Taxonomy.
• Snodgrass R. E. (1875)– referred as a Father of Insect
Morphology. He wrote book - Principles of Insect Morphology.
• Mithan Lal Runwal (1908)– Outstanding work on termites/
white ants. Contributions to ecology, embryology and locust.
• Dr.S.Pradhan (1969) - Wrote a "Insect Pests of Crops" and
Father of Modern Applied Entomology in India.
Contribution of Scientists

o 1912– Plant Quarantine Act.
o 1914–Destructive Insects and Pests Act (DIPA).
o 1916–Imperial Forest Research Institute at Dehradun.
o 1925–Indian Lac Research Institute started at Ranchi.
o 1937–A laboratory for storage pests was started at Hapur, U.P.
o 1937- Establishment of Entomology division at IARI New Delhi.
o 1939–Locust Warning Organization established.
o 1946–‘Directorate of Plant Protection, Quarantine & Storage.
o 1968– ‘Central Insecticide Act’.
Institutes/Organizations

• NCIPM, New Delhi-(National Centre for
Integrated Pest Management - 1988).
• PDBC, Bangalore-(Project Directorate of
Biological Control -1993).
• NBAIR-National Bureau of Agricultural Insect
Resources.
• CIB, Faridabad – Central Insecticide Board.
• NPPTI, Hyderabad–National Plant Protection
Training Institute.
Entomological Institutes

Classification of Phylum Arthropoda

The most diverse insect Orders under class Insecta
• Coleoptera: beetles, weevils
• Hymenoptera: ants, wasp, bees
• Lepidoptera: butterflies, moths
• Diptera: flies
• Hemiptera: bugs, aphid, leaf hopper
• Orthoptera: locust, cricket,, grasshoppers.
• Isoptera: termites
• Thysanoptera: thrips

Insect orders
Coleoptera- beetles, weevils
•This refers to how their first pair of wings
have hardened into an elytra (hardened
forewings), that covers the second pair of
wings (and usually the entire abdomen) as
a protective case.
Hymenoptera- ants, wasps, bees, Sawflies
• Some of the members of this order are
hugely important as pollinators,
predators or pests.
• The front and hind wings are locked
together by a tiny row of hooks (male and
queen ants have wings).

Insect orders
Lepidoptera – butterflies, moths,
silkworm.
• Moths are usually active during the
night.
• Club like antennae, compound eye,
complete metamorphosis.
• Presence of powder on its body, these
are the tiny scales that give the group
its name.
Diptera – flies
• In flies, their second pair of wings are
reduced called halters, which act as a
balance and guiding system.
• Serious pest of Horticultural-fruit
crops.

Insect orders
• Hemiptera – cicadas and
true bugs
• Hemiptera means half-
wing.
• This is because the first
pair of wings is hardened
at the base while part of
the wing is thin and
membranous.
• have piercing mouthparts
used to suck up fluids,
usually from plants.

Insect orders
• Orthoptera- crickets,
locust, grasshoppers.
• have a generally
cylindrical body, with
elongated hindlegs and
musculature adapted for
jumping.
• They have mandibulate
mouthparts for biting and
chewing and large
compound eyes.

Classification of insects
On the basis of host association:
Monophagous insects: These insects depends only one
species of plants for whole life-cycle. Eg., Bombyx mori
on Morus alba.
Oligophagous insects: Confined only one family for the
whole life-cycle Eg., Potato tuber moth: depends on the
solanaceous crop Diamond back moth (Platella
xylostella, Platellidae) feeds on crucifer crops Cabbage
butterfly (Pieris brassicae) feeds on crucifer crops.
Polyphagous insects: Many agricultural pests fall on
polyphagous pests. Those insect-pests visit the diverse
plant species to complete the life cycle. Eg., Helicoverpa
armigera, Noctuidae If on chickpea: chickpea borer If
on tomato: tomato fruit borer.

Classification of insects:
On the basis of plant part damage:
a) Leaf damaging insects: Caterpillar, bug, thrips,
aphids
b) Stem damaging insects: Rice stem borer, mango
stem borer, Orange stem borer.
c) Fruit damaging insects: Citrus fruit fly.
d) Root damaging insects: Red ants, White grub
e) Flower damaging insects: Thrips

• L
Locust Termite
White Grub
Pests of National Importance

Entomology may be divided into 2 major aspects-
1. Fundamental Entomology/General Entomology:
• It deals with the basic or academic aspects of the Science of
Entomology.
• It includes morphology, anatomy, physiology and taxonomy of
the insects.
2. Applied Entomology/Economic Entomology:
• It deals with the usefulness of the Science of Entomology for
the benefit of mankind.
• Applied entomology covers the study of insects which are
either beneficial or harmful to human beings.
• beneficial insects like predators, parasitoids, pollinators or
productive insects like honey bees, silkworm and lac insect.
• studies the methods in which harmful insects or pests can be
managed without causing significant damage or loss to us.
Economic Importance of Insects

1.Insects of No economic importance:-
insects found in forests, and agricultural lands which neither cause
harm nor benefit us.
2. Insects of economic importance:-
A. Injurious insects-
(i).Pests of cultivated plants- Each cultivated plant damage by many
insect pests which feed on them reduces the yield of the crop. E.g.
cotton bollworm, Rice stem bores.
(ii).Storage pests- Insects feed on stored products and cause economic
loss. E.g. Rice weevil, Pulse beetle.
(iii).Pest attacking cattle and domestic animals- Cattle are affected by
pests like Horse fly, Fleas and Lice. They suck blood and sometimes
eat the flash.
(iv).House hold and disease carrying insects- House hold pests include
cockroach, ants, etc. Disease carrying insects are like
mosquitoes, houseflies, bed bugs, fleas etc.

B. Beneficial insects-
(i) Productive insects:
Silk worm- The silk worm filament secreted from the salivary
gland of the larva helps us in producing silk.
Honey bee- Provides us with honey and many other
byproducts like bees wax and royal jelly.
Lac insects-The secretion from the body of these scale insects
is called lac.
Insects useful as drugs, food, ornaments -
As medicine - Sting of honey bees- remedy for rheumatism
and arthritis. Extracted from blister beetle –useful as hair
tonic.
As food- for animals and human being. For animals- aquatic
insects used as fish food.
Grasshoppers, termites, pupae of moths. They have been used
as food by human beings in different parts of the world.
Ornaments, entertainers-
-Artists and designers copy colour of butterflies.
- Beetles worm as necklace.
-Insect collection is a hobby.
Scientific research
Drosophila and mosquitoes are useful in genetic and
toxicological.

B. Beneficial insects-
(ii) Helpful insects:
(a)Parasites: small insects which feed and live on harmful
insects by completing their life cycle in a host and kill the
host insect. e.g. egg, larval and pupal parasitoids.
(b)Predators: These are large insects which capture and devour
harmful insect. e.g. Coccinellids family and Preying Mantid.
(c)Pollinators: Many cross pollinated plants depend on insects
for pollination and fruit set. e.g. Honey bees.
(d)Weed killers: Insects which feed on weeds kill them thereby
killers. E.g. Mexican beetle eats on Parthenium. Cochineal
insect feeds in Opuntia dillenii.
(e)Soil builders: soil insects such as ants, beetles, larval of
cutworms, crickets,termite, collombola, make tunnels in soil
and facilitate aeration in soil. They become good manure
after death and enrich soil.
(f) Scavengers: Insects which feed on dead and decaying matter
are called scavengers. They important for maintaining
hygiene in the surroundings. E.g. Carrion beetles, Rove
beetles feed on dead animals and plants.

House hold and disease carrying insects
i) Pests which cause damage to
belongings of human being like
furniture, wool, paper, etc.
e.g. Cockroaches, beetle, sliver
fish etc.
ii) Pests which cause painful bite,
inject venoms. e.g. Wasps, bees
sting us. Hairy caterpillar nettling
hairs are poisonous. Mosquitoes,
bugs bite, piece and suck blood.
iii)Disease causing Mosquito-
Malaria, Filariasis, dengue fever.
Housefly- Typhoid, Cholera,
Leprosy, Anthrax.

Metamorphosis
Metamorphosis is a biological process by which an
animal/insect physically develops after birth or
hatching, involving a conspicuous and relatively
abrupt change in the body structure through cell
growth and differentiation.
“Radical changes in morphology during development
of insect ”.
Both complete and incomplete metamorphosis extend
from the egg stage to the adult stage.
Complete metamorphosis consists of four stages: egg,
larva, pupa, and adult. However, the incomplete
metamorphosis consists of three stages: egg, nymph,
and adult.

Metamorphosis
The main difference between complete
metamorphosis and incomplete metamorphosis is
that complete metamorphosis consists of a very
active, speedy eating larva and an inactive pupa i.e.
Complete metamorphosis occurs in wasps, ants,
butterflies, bees, beetles, moths.
Whereas, incomplete metamorphosis consists of a
nymph, which resembles a miniature adult. while
incomplete metamorphosis occurs in termites,
praying mantis, and cockroaches.

TYPES OF
LARVAE
Nymph
Hemiptera
bugs, hopper,
whiteflies,
aphids, jassids.
Caterpillar
Lepidoptera
Moth,
bollworms, borer
Grub
Hymenoptera
Coleoptera
Beetles, weevils
Maggot
Diptera
All flies (white
flies, MSF)

Mouth Parts of an Insects
• Maxilla: it cuts the food materials i.e.
cutting of food.
• Mandible: it crushes the food material
i.e. crushing of food.
• Labium: it acts like lower lip.
• Labrum: it acts like upper lip. Labium
and labrum saves the food material
from to come out from mouth.
• Hypopharynax: it works like tongue.

Modifications of Mouth Parts of an Insects
• Piercing and sucking types (piercing the tissues of
animals and plants to suck blood and plant juice):
Mosquito, aphids, bugs, leafhopper, jassid, thrips.
• Sponging type (sucking up liquid): Housefly
• Siphoning type (mouth parts are adapted
wonderfully for sucking flower nectar and fruit
juice, ): Butterfly and moths
• Chewing and lapping type (modified for collecting
the nectar and pollen from flowers and also for
moulding the wax, ): Honey bees, wasp.
• Chewing/biting/cutting types (mandibles are paired
and bear toothed edges): grasshopper, larvae (all),
locust, cricket, beetles, weevils.

Damaging Stages of Insects
• Coleoptera: larvae (grub)+
adult moth stage.
• Lepidoptera: only larvae
(caterpillar), adult of fruit
sucking moth.
• Hemiptera: Nymph+ adult both
stages.
• Diptera: Generally Nymph.

Modification of Insects Legs
• Walking type: Cockroach and bugs
• Running type: Ants
• Jumping type: Grasshopper, crickets
• Sound producing: hind legs of
grasshopper /cricket
• Digging type: mole cricket
• Swimming type: dytiscus beetle and
water bug
• Pollen collecting: honeybees
• Climbing and sticking : housefly
• Raptorial/Grasping: Mantis
• Clasping type: Pyrilla

Continue….
Walking type Running type Jumping type
Sound producing Digging type Swimming type

Continue….
Pollen collecting Climbing and sticking
Raptorial/Grasping: Clasping type

Structure and Modifications of Insect Antennae
Antennae sometimes referred to as "feelers", are
paired appendages used for sensing in
arthropods. Antennae are connected to the first one
or two segments of the arthropod head.
Functions of Antennae:
• Antennae serve different sensory functions for
different insects.
• It detect odours and tastes, wind speed and
direction, heat and moisture, and even touch.
• A few insects have auditory organs on their
antennae, so they're involved in hearing.
• Mosquitoes detect sounds with their antennae,
• and many flies use theirs to gauge air speed
while they are in flight.

Structure of Antennae:
Scape- the first basal segment, it is the point of
articulation to the head capsule, and is often
conspicuously longer than other segments.
Pedicel - this is the second segment that follows
scape, and it has a specialized sensory organ (known
as Johnson’s organ) with which insects could hear
sounds.
Flagellum - also known as the Clavola, it is further
divided into three parts.
• Ring joints: this is the basal segment of the
flagellum which are small and ring-like form.
• Club: this is the swollen or enlarged distal
segments of the antenna.
• Funicle : the segments between ring joints and
club.

Types of Insect Antennae
Aristate:
It is pouch-like, with a
lateral bristle called
arista on its dorsal side.
Aristate antennae are
most notably found in
the Diptera (true flies).
e.g. Housefly.

Types of Insect Antennae:
Capitate:
 have a prominent club or
knob at their ends.
 last three segments are
suddenly enlarged.
 The term capitate
derives from the Latin
caput, meaning head.
 Butterflies (Lepidoptera)
often have capitate form
antennae.

Clavate:
 Terminate in a gradual
club or knob (unlike the
capitate antennae, which
end with an abrupt,
pronounced knob).
 This antennae form is
found most often in
beetles, butterflies such
as in carrion beetles.

Filiform:
 Comes from the Latin
filum, meaning thread.
 Filiform antennae are
slender and thread-like in
form.
 Examples of insects with
filiform antennae include:
Grasshopper, Ground and
long horned beetles.

Flabellate –
• from the Latin flabellum,
meaning fan.
• In flabellate antennae, the
terminal segments extend
laterally, with long, parallel
lobes that lie flat against one
another.
• This feature looks like a
folding paper fan.
• Found in Coleoptera,
Hymenoptera, Lepidoptera.

Lamellate
• Comes from the Latin
lamella, meaning a thin plate
or scale.
• In lamellate antennae, the
segments at the tip are
flattened and nested, so
they look like a folding fan.
• To see an example of
lamellate antennae, look at a
scarab beetle.

Geniculate:
• Geniculate are bent or
hinged sharply, almost like
a knee or elbow joint.
• The term geniculate derives
from the Latin genu,
meaning knee.
• Geniculate antennae are
found mainly in ants or
bees.

Moniliform
• comes from the Latin monile,
meaning necklace.
• Moniliform antennae look
like strings of beads.
• The segments are usually
spherical, and uniform in size.
• The termites are a good
example of insects with
moniliform antennae.

Pectinate
• Segments of pectinate
antennae are longer on one
side, giving each antennae a
comb-like shape.
• Bi-pectinate antennae look like
two-sided combs.
• The term pectinate derives
from the Latin pectin, meaning
comb.
• Pectinate antennae are found
mainly in some beetles and
sawflies.

Plumose
• Brush like with dense hairs.
• Segments of plumose
antennae have fine branches,
giving them a feathery
appearance.
• The term plumose derives from
the Latin pluma, meaning
feather.
• Insects with plumose antennae
include some of the true flies,
such as mosquitoes, and
moths.

Serrate
• Segments of serrate
antennae are notched or
angled on one side,
making the antennae look
like a saw blade.
• The term serrate derives
from the Latin serra,
meaning saw.
• Serrate antennae are
found in some beetles.

Setaceous
• Comes from the Latin
seta, meaning bristle.
• Setaceous antennae
are bristle-shaped and
tapered from the base
to the tip.
• Cockroach, dragonflies
and damselflies

Stylate
• comes from the Latin stylus,
meaning pointed instrument.
• In stylate antennae, the final
segment terminates in a long,
slender point, called a style.
• The style may be hair like but
will extend from the end and
never from the side.
• robber flies, snipe flies, and bee
flies.

Fundamental of entomology Dr.Sunil Prajapati

Fundamental of entomology Dr.Sunil Prajapati

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