3. INTRODUCTION
The use of certain chemicals in
the form of dust, sprays,
granules, and, gases to control
insect population .
Substances that prevent, inhibit,
destroy, kill insects are called
insecticides
4. INSECTICIDES
Natural Insecticides.
• Pyrethrum (flower extract)
• Nicotine (tobacco extract)
• Rotenone (root extract)
• Safer’s Insecticidal Soap , etc.
Synthetic Insecticides.
• Organochlorenes
e.g. :- DDT ,BHC ,Aldrin , etc.
• Organophosphates
e.g. :- Malathion, etc.
• Carbamates
e.g. :- Carbaryl ,Dimetlian ,etc.
6. DUSTS:
These are the simplest of formulations
and the easiest to apply .
In a formulated dust following mixtures
are found:
a) Undiluted toxic agent, e.g., sulfur dust
used for control of mites and powdery
mildew .
b) Toxic active ingredient plus an inert
diluent .
Dusts are the least effective and,
although prices are lower, have the least
economic return.
e.g. : Tri-Die Silica & Pyrethrum Dust and
D-Fense Deltamethrin Dust .
7. GRANULES:
In this type of formulation the
chemical is in the form of small
granules of inert material.
The size of the granules varies from
20 to 80 mesh .
The a.i. of the granules varies from
3% to 10% in India, but may be up to
25% in some countries.
e.g. : "Triton X 45" and
carbofuran granules.
8. FUMIGANTS:
Fumigants are volatile poisons and enter
the body of the insects through the
respiratory system.
The chemical may be applied as a gas or
as a volatile liquid.
Fumigants are the insecticides that
forms gases or vapors toxic to insects
and microorganisms.
All types of insects can be killed by
fumigants irrespective of the types of
mouthparts .
e.g.:- paradichlorobenzene and
methyl bromide , etc.
9. SPRAYS:
In spraying, the chemicals to be
applied are dissolved or
suspended in water or less
commonly in an oil-based carrier.
The mixture is then applied as a
fine mist to plants, animals, soils,
or products to be treated .
e.g. : Hydrogen cyanide , Nicotine,
Naphthalene .
10. ADVANTAGES:
Cost effectiveness
Timeliness and Flexibility
Chemicals are easy to use
in controlling insects.
Works with great
efficiency.
DISADVANTAGES:
Reduction of beneficial
species.
Residues in food for human
and feed for live stock.
Poisoning hazards and other
health effects.
13. INTRODUCTION
Natural control strategies that
employ biological agent for
insect pest suppression.
This management activity is
designed to protect or conserve
natural enemies .
Started to emerge in 1870 in
U.S.A .
Charles Valentines Riley ,
“Father of Modern Biological
control”
15. IMPORTATION / CLASSICAL
:
Classical biological control involves
the introduction of pests natural
enemy to a new location where they
do not occur naturally.
Parasitoidal wasps Trichogramma
ostriniae to control European corn
borer Ostrinia nubilalis .
16. AUGMENTATION :
Involves the supplemental release of natural enemies ,
boosting the naturally occurring population.
Periodic releases of augmentation:
Inoculative release.
Inundative release.
17. PERIODIC RELEASES OF AUGMENTATION
Inoculative release: Small numbers of the control agents
are released at intervals to allow them to reproduce in
the hope of setting up longer term .
e.g. ; Encarsia formosa Green house white fly,
Phytosieulus persimilis Spotted spider mite.
Inundative release : Involves mass culture and release
of natural enemies to suppress the pest population
directly.
e.g. ; massive release of Trichogramma sp. in vegetable
or field crops.
18. CONSERVATION :
Involves avoidance of measures that destroy natural
enemies and use of measure that increases their
longevity and reproduction of the natural enemies.
Natural enemies are already adapted to the habitat and
to the target pest.
Conservation involves :
Avoid harmful cultural practices
Maintenance of diversity
Protection from pesticides/insecticides.
19. BIOLOGICAL CONTROL AGENTS
The biocontrol agents protect plants from their natural enemies
like parasites, from predation, etc.
They help in controlling the infestation of plant pests such as
weeds, nematodes, insects, and mites.
PREDATOR
PARASITOIDS
PATHOGENIC MICROORGANISMS
Bacteria
Fungi
Viruses
20. PREDATORS:
Predators are mainly free living
species that directly consumes a
large number of prey .
Examples :-
i. lady bugs Aphids
ii. Spotted lady beetle larvae of
Colorado potato beetle
iii. Gambusia sp. fish mosquito
larvae
21. PARASITOIDS :
Lays their eggs on the body of an insect host which is then used
as a food for developing larvae.
IMPORTANT GROUPS ARE :
i. Ichneumonid wasps – mainly on caterpillars of butterflies
ii. Braconid wasps- attack caterpillar and other insects
iii. Chalcid wasps- parasites eggs and larvae of green and white fly
iv. Tachinid fly- larval beetles , caterpillars and true bugs.
22. PATHOGENIC MICROORGANISMS :
1. BACTERIA
Bacteria are used for biological control , infect insects via their
digestive tract .
e.g. :- Bacillus thuringiensis Lepidoptera , Diptera .
Bacillus sphaericus Diptera.
2. FUNGI
They can infect wide range of insect hosts.
There has been limited success in Fungi as biological agent.
e.g. :- Verticillium lecanii aphids and white flies.
Lagenidium giganteum mosquito larvae.
23. 3. VIRUSES
Viruses are obligate disease causing organisms.
Viruses are host specific.
Provide safe , effective and sustainable control
of variety of insects .
Baculoviruses are arthropod specific :
Two Genera :
i. Nuclear polyhedrovirus.
ii. Granulovirus .
e.g. :- Lymantria dispar Gypsy moth
24. Advantages:-
Absence of toxic effects.
No development of
resistance.
No residues of poisons.
No build up of toxins .
No killing of pollinators or
secondary pests.
Disadvantages:-
Control is slow.
It is often unpredictable.
It requires expert
supervision.
Very expensive.
Difficult to develop and
apply.
25. REFERENCES :-
Burges , H.D. and Hussey , N.W. Microbial control of
insect pest.
Saxena A.B. Biological control of insect pest.
An Introduction to insecticides , George W. Ware.
Wikipedia.
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