This document provides an overview of plant pests including insects, fungi, bacteria, viruses, and nematodes. It describes the different feeding habits of insects such as chewing, siphoning, sponging, and piercing and sucking. Based on feeding habit, different types of agrochemicals including contact, stomach, and systemic pesticides are suitable. Fungi enter plants through openings and cause diseases like powdery mildew and rust. Bacteria also enter through openings and can cause rot, galls, or blockages. Viruses replicate inside host cells and are very difficult to treat once a plant is infected. Controlling vectors, practicing phyto-sanitation, using resistant varieties, and keeping plants healthy are

1. Basics of Plant Protection
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2. INSECTS
Classification according to Eating Habits and Mouth Parts

3. Chewing
Sub Types
– Rasping and Chewing- Grass
Hoppers, Larvae
– Borers- Stem Borer, Leaf Miners,
Fruit Borers, weevils
– Cutters- Termites
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4. Chewing-
Primitive Mouth Parts for holding and
chewing
– Labrum - a cover which may be
loosely referred to as the upper lip.
– Mandibles - hard, powerful cutting
jaws.
– Maxillae - 'pincers' which are less
powerful than the mandibles. They
are used to steady and manipulate
the food. They have a five segmented
palp which is sensory and often
concerned with taste.
– Labium - the lower cover, often
referred to as the lower lip. It actually
represents the fused pair of ancestral
second maxillae. They have a three
segmented palp which is also sensory.
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5. Modified Chewers
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Insect Larvae
Termite- Cutting Type
Weevil

6. Siphoning
Rolled Proboscis
made from Highly
Modified Maxillae
Siphoning insects
don’t Peirce but
suck the Nectar
from the flower,
e.g.. Moths,
Butterfly
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7. Sponging ( Surface Sucking)
Proboscis converted into
absorbent sponge
Feed from the surface of
the liquid or the wet area
E.g.. House Fly, Fruit Fly
( Drosophila)
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8. Piercing and Sucking
Peirce the surface and suck the sap
from the plant
Mostly found under the leaf or on
tender shoot
Cause Secondary infection by
providing entry point to the
Pathogens and by acting as vectors
of Viral Diseases.
E.g., Aphids, Jassids, White Fly,
Thrips
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10. How Knowledge Feeding Habit Helps
in Control Strategy of Pests?
All Agrochemicals act on Pests in one or more
out of the following ways
– Contact- Agrochemical kills the insect by Physical
contact or by Fumes or both.
– Stomach- When the insect ingests the plant part
or bait laced with insecticide.
– Systemic- When insecticide is absorbed in the
whole plant sap the Insect sucks the poisoned sap
of the plant.

11. Which type of Agrochemical to use?
Feeding Habit Mode of action suitable
Contact/Fumig
ant
Stomach Systemic
Rasping and
Chewing
Boring
Cutting
Piercing and
Sucking
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12. Characteristics of types of
Agrochemicals
Contact- Highly Toxic and mostly Fumigant action,
It has to reach the target pest directly during
spraying. It is non selective and kills non target
organisms also.
Stomach- Has to cover the entire plant so that
any part eaten by insect may carry it to insect
system
Systemic- Has to be applied either through roots
or through foliage so that it permeates the
Phloem sap. Safe to Predators and non target
organisms
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14. Label Colour Common Pesticides
Red Monocrotophos, DDVP, Methyl Parathion, Phorate,
Carbofuran, Zinc Phosphide
Yellow Chlorpyriphos, Cypermethrin, Cartap Hydrochloride,
Quinolphos
Blue Malathion,Carbaryl, Dicofol, Thiomethoxam,
Carbendazim, Copper Oxychloride, Metalyxyl,
Glyphosate, Tridimefon
Green Mancozeb, Sulphur, Benomyl, Chlorthanlonil, Oxyflourfen,
Neem Based Formulations

15. Other Pests
Fungus
Bacteria
Virus
Nematodes
MLO
Rodents

16. Fungus (Pl. Fungi)
Parasitic Fungi cause largest number of
diseases in the plants, causing mild to fatal
damage to the plant
Fungi enter the plant through a natural
opening, such as a stoma (microscopic air
pore) in a leaf, a lenticel (small opening
through bark) in a stem, a broken plant hair or
a hair socket in a fruit, or a wound in the plant
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17. Fungal Diseases
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Downy Mildew
Smut
Powdery Mildews
Rust Wilt Blight

18. Bacteria
Only a few Bacterial species are parasitic to
plants.
Bacteria also enter the plant through entry points
as fungi
Bacterial Infections cause one or more of the
following-
– Cell Wall Degradation causing Rot
– Unusual Auxin secretion causing Galls
– Polysaccharide formation causing blockage of Xylem
leading to death
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19. Bacterial Diseases
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Crown Gall Leaf Blight
Wilt
Leaf Spot Canker

20. Virus
Virus consist of a genetic material covered by a protein coating for
protection. It has no cell structure and can reproduce only inside a living
Host cell
Virus frequently transform into crystalline form having all characteristic of
Non Living substance and when they get a live cell, they proliferate just
like a living organism.
Virus is virtually indestructable, as they use Host Cell to replicate, In
plants, it is economically unviable to kill virus, only its spread through
Vectors ( mainly Insects) can be prevented
There is no remedy available for viral disease, only its symptoms can be
suppressed for some time.
It is advisable to either Burn or bury the plant affected by virus and control
vectors such as White Fly, Thrips etc. for preventing further spread
Resistant and tolerant varieties to be used wherever available
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21. Viral Diseases
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22. Other Disease Causing Agents
Nematodes- Molya Disease of Wheat, Root
knots of Tomatoes
Mycoplasma Like Organisms- Little Leaf
Disease of Brinjal
Physiological Agents- Heat, Sun, Cold,
Hormone Imbalance, Nutritional Deficiency,
Chemicals etc.
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23. Principals of cure
All plant Diseases spread due to an external reason. Hence
to prevent them, eliminate that reason-
– Take care of wounds
– Keep Vectors under check
– Observe Phyto-sanitation
Invest in Prevention of diseases
– Use healthy seed from a reliable source
– Use resistant varieties.
– Seed Treatment
– Soil Treatment
– Prophylactic Spraying of Fungicides and Antibiotics
Keep the Plant healthy with proper nutrition- for natural
disease resistance.
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24. Thanks
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