Ecological manipulation in pest management

entomology

1. WEL COME

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

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

4. 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.

5. 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.

6. 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.

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

8. Ecological means of controlling pest:

9. 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.

10. 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.

11. 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.

12. 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.

13. (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.

14. 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.

15. 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.

16. 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.

17. 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.

18. 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.

19. 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.

20. Egg parasitoid : Trichogramma australicum Early larval parasitoid – Apanteles taragama Mid larval parasitoid – Bracon hebtor Prepupal parasitoid – Gonizus nephantidis Pupal parasitoid - Trichospilus pupivora , Testrastichus israeli

21. 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.

22. 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

23. 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.

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

25. 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.

26. THANK YOU