2. Presentation on ecological manipulation in pest
management
PRESENTED BY : Pramila choudhury
PG17AGR9026
Agril.entomology

3. INTRODUCTION
IMPORTANCE OF ECOLOGY IN PEST MANAGEMENT
ECOLOGICAL MANIPULATION
ECOLOGICAL MEANS OF CONTROLLING PEST
CONCLUSION

4. What is ecology?
Ecology is the scientific study of relationships in the
natural world. It includes relationships between
organisms and their environments .

5. What is pest?
•A pest is any organism whose population increases
to such an extent as to cause economic loss to
crops and health hazard to man and domestic
animals.

6. Importance of Ecology in Pest Management:
Indiscriminate uses of pesticides lead to a
regular resurgence of pests due to the fact
that the natural enemies get killed. The
increase in pest population is also due to the
interference of man by monoculture, using
high yielding and susceptible varieties, giving
more number of irrigations, use of high
nitrogenous fertilizers etc.

7. Cont…
Because of which the balance of life in
nature gets upset and the pest appears in
severe form every year. The importance of
ecology was then felt and integrated
approaches in pest management are now
made to avoid the violent fluctuations in
pest populations.

8. ECOLOGICAL MANIPULATION:
•Ecological manipulations are planned
environmental changes that are implemented to
produce a change in behaviour of any organism.

9. Ecological means of controlling pest:
Cultural method
Ecological engineering
Biological control
Integrated pest management
Agro ecosystem analysis

10. 1.CULTURAL CONTROL:
•The manipulation of cultural practices at an
appropriate time for reducing or avoiding pest
damage to crops is known as cultural control. The
cultural practices make the environment less
favorable for the pests and or more favorable for
its natural enemies. It is the cheapest of all
methods.

11. •i) Proper preparatory cultivation:
• Several insects which live or hide in the soil get
exposed to sun as well as predators like birds etc
due to Proper preparatory cultivation. Eg.Pupae
of moths, roots grubs etc.
• ii) Clean cultivation: Removal of weeds which act
as alternate hosts.
• Eg. Paddy gall fly Orseolia oryzae breeds on
grasses such as Panicum sp., Cynodon dactylon
etc. Fruit sucking moth larvae on weeds of
MENISPERMACEAC.

12. • Iv)Changes in the system of cultivation :
• Change of banana from perennial to annual crop reduced
the infestation of banana rhizome weevil Cosmopolitus
sordidus in addition to giving increased yields.
• Avoiding ratoon redgram crop during offseason helps in
reducing the carry over of pod fly Melangromyza obtusa
and eriophyid mite Aceria cajani
•
• v) Crop rotation: Crop rotation is most effective practice
against pests that have a narrow host range and dispersal
capacity. Lady’s finger followed by cotton will suffer from
increased infestation of pests. Hence if a non-host crop is
grown after a host crop,it reduces the pest population.

13. • vi) Growing resistant varieties: certain varieties
resists pest attack . Eg: GEB-24 and MTU–5249
resistance to paddy BPH, Surekha variety to gall
midge, TKM -6 and Ratna for stem borer.

14. • (b) Cultural practices specially adopted for certain pests
• 1. Adjusting planting or sowing or harvesting times to
avoid certain pests :
• The manipulation of planting time helps to minimize pest
damage by producing asynchrony between host plants
and the pest or synchronizing insect pests with their
natural enemies
• . Eg. Early planting of paddy in kharif and late planting in
rabi minimize the infestation of rice stem borer.
• Early sown sorghum in kharif reduces the infestation of
shoot fly
• Timely and synchronous planting has been found to
reduce bollworm damage in cotton and stem borer
damage in sugarcane.

15. • 2. Trap cropping: Growing of susceptible or preferred plants for
important pests near a major crop to act as a trap and later it is
destroyed or treated with insecticides. Trap crop may also attract
natural enemies thus enhancing natural control.
• : Trap crop Main crop Insect pest
Chillies castor Tobacco caterpillar
Tomato Citrus Fruit sucking moths
Marigold Cotton American bollworm
• 3. Flooding the field is recommended for reducing the attack of
cutworms, army worms, termites, root grubs .
• 4. Draining the fields: In case of paddy case worm which travel from
plant to plant via water. it can be eliminated by draining or drying the
field.

17. 2. ECOLOGICAL ENGINEERING
•Ecological engineering for pest
management
has recently emerged as a paradigm
for considering pest management
approaches that rely on the use of
cultural techniques to effect habitat
manipulation and to enhance biological
control.

18. Ecological engineering for pest management
• Raise the flowering plants / compatible cash crops
along the orchard border by arranging shorter plants
towards main crop and taller plants towards the
border to attract natural enemies as well as to avoid
immigrating pest population
• Grow flowering plants on the internal bunds inside the
orchard
• Not to uproot weed plants those are growing naturally
like Tridax procumbens, Ageratum sp, Alternanthera
sp etc. which act as nectar source for natural enemies,
• Not to apply broad spectrum chemical pesticides.

19. •Natural enemies may require
• Food in the form of pollen and nectar for adult natural enemies
• Shelters such as overwintering sites, moderate microclimate etc.
• Alternate host when primary host is not there.

20. •Due to enhancement of biodiversity by the
flowering plants, parasitoids and predators (natural
enemies) number also will increase due to
availability of nectar, pollen, fruits, insects, etc. The
major predators are a wide variety of spiders,
ladybird beetles, long horned grasshoppers,
Chrysoperla, earwigs, etc.

21. 3.Biological method
•The successful management of a pest by means of
another living organism (parasitoids, predators
and pathogens) that is encouraged and
disseminated by man is called biological control. In
such programme the natural enemies are
introduced, encouraged, multiplied by artificial
means and disseminated by man with his own
efforts instead of leaving it to nature.

22. 1. Egg parasitoid : Trichogramma australicum
2. Early larval parasitoid – Apanteles taragama
3. Mid larval parasitoid – Bracon hebtor
4. Prepupal parasitoid – Gonizus nephantidis
5. Pupal parasitoid - Trichospilus pupivora, Testrastichus
israeli

24. 4.Integrated pest management
•IPM is an ecosystem-based strategy that focuses
on long-term prevention of pests or their damage
through a combination of techniques such as
biological control, habitat manipulation,
modification of cultural practices, and use of
resistant varieties.

26. 5.Agro Ecosystem Analysis (AESA)
AESA is an approach which can be
gainfully employed by extension
functionaries and farmers to analyse
field situations with regard to pests,
defenders, soil conditions, plant
health, the influence of climatic
factors and their interrelationship for
growing healthy crop. Such a critical
analysis of the field situations will
help in taking appropriate decision on
management practices.
involves three steps
Observation → Analysis → Decision
making

27. AESA METHODOLOGY:
• Go to the field in groups. Walk across the field and choose 10
plants randomly. Observe keenly each of these plants and
record your observations:
• Plant: observe the plant height, number of tillers, crop stage,
deficiency symptoms, etc.
• Pests: observe and count pests at different places on the plant.
• Defenders: observe and count parasites and predators.
• Diseases: observe leaves and stems and identify any visible
disease symptoms.
• Rats: count numbers of plants affected by rats.
• Weeds: observe weeds in the field and their intensity.
• Water: observe the water situation of the field.
• Weather: observe the weather condition.
• Soil condition.

28. Draw a chart what we have observed in the
field.

29. CONCLUSION
•The health of a plant is determined by its
environment. This environment includes abiotic
factors (i.e. sun, rain, wind and soil nutrients) and
biotic factors (i.e. pests, diseases and weeds).
•All these factors can play a role in the balance,
which exists between herbivore insects , their
natural enemies and with their environment. If we
understand the whole system of interactions, we
can use this knowledge to reduce the negative
impact of pests and diseases.