Biocontrol Agents

Biological Control agents ,their types, advantages and disadvantages

1. BIOCONTROL AGENTS   Presented By:  RAKSHANDA NATH (BSBN1BT18015) Tejasv Gupta(BSBN1BT18026)   Deeksha Soni(BSBN1BT18003)

2. Contents Introduction History Types of Biocontrol  Strategies of biological pest control Types of Biocontrol Agents Advantages  Disadvantages Conclusion References

3. What is Biocontrol ? Biocontrol is the application of one living organism to control another: also referred to as a biological pest control. The aim of biocontrol is not to eradicate the invasive species, but control it in a way that it becomes manageable.  In other words, the method uses nature’s own in-built mechanisms to ensure equilibrium. It is a self-sustaining and long-term treatment method, for managing invasive plants and pests.  The living organism applied in this system is used to suppress a weed infestation. Furthermore to control pests (including insects, pathogens, and grazing animals).

4. Biocontrol Agents  Biological control or biocontrol is a method of controlling pests such as insects, mites, weeds and plant diseases using other organisms. It relies on predation, parasitism, herbivory, or other natural mechanisms, but typically also involves an active human management role. They play an important role in controlling the plant pests like parasitic nematodes, weeds, parasitic nematodes, and mites.  The biological control agent helps in maintaining and balancing the plant species along with their natural enemies.

5. History The term "biological control" was first used by   Harry Scott Smith  in 1919 . It was brought into more widespread use by the entomologist Paul H. DeBach who worked on citrus crop pests. Riley in 1873, shipped the predatory mites  Tyroglyphus phylloxera  to help fight the grapevine phylloxera ( Daktulosphaira vitifoliae ) that was destroying grapevines in France.

6. Types Of Biocontrol  Inundative Biocontrol This approach uses pathogens, applied on a target weed at a very high rate in an aspect that is almost similar to herbicide application.  The most common pathogens used in inundative bio-control include parasitic nematodes and nuts.  This approach does not prevent the invasive plant from increasing at a later date.

7. Classical Biocontrol It uses agent populations that would waver in a natural prey and predator relationship.  This method adopts natural predatory insects of the invasive plant.  It creates an eternal relationship between a plant and biological control animals.

8. Strategies of Biological Pest Control

9. Types of Agents Parasitoids Predators Entomopathogens Entomopathogenic Bacteria  Entomopathogenic  Baculoviruses Entomopathogenic Fungi Protozoans Entomopathogenic Nematodes(EPN)

10. Parasitoides An organism that during its development live in or on the body of the host, eventually kills the host in process of parasitism. Types of Parasitoid: Egg Parasitoid : eg - small worm Larval Parasitoid : eg - Apanteles Pupal Parasitoid : eg - Xanthopimpla spp. Adult and Nymphal Parasitoid :   eg -   Epricania melenoleuca

11. Predators These consume on many prey over the course of their development, they are free living and they are usually are big as their prey or bigger. Some predators are only predaceous only in their larval stage like syrphid fly. Other predators are found in field in the  different cropping system are lad beetle, praying mantis, etc .

12.    ENTOMOPATHOGENS                 →

13. Entomopathogenic Bacteria Example - Bacillus thuringiensis (B.T.) Larvae consume foliage treated with Bt.(spores and crystals). BT-endotoxin attack on mid gut. The mid gut wall breakdown allowing Bt. into the haemocoel and killing the larvae into 1-2 days.

14. Entomopathogenic Virus Example - Nuclear Polyhedrosis Virus (NPV) Infection of baculovirus generally occur by ingestion occulded or free virion. Ingested virion attack mid gut- occulded bodies dissolve by protease enzyme  Free virion reach haemocoel, circulatory system and respiratory system and attack there.

15. Entomopathogenic Fungi Example - Beauveria spp. & Metarhizium spp. Spores (conidia) contact with integument, germinate and develop hyphae. Hyphae enter in haemocoel and develop mycelium. Produce toxin- insect die.

16. Protozoa Pathogen Protozoa kills the insects either directly or by reducing the fecundity of the adult and their effect on the host is chronic. The prolong the larval life in the field, thus exposing the insect longer to predators and parasitoids. Infected insect may be sluggish and smaller than normal.      eg : Nosema melolonthae   against chaffer beetles      Nosema locustae against grass hoppers. 

17. Entomopathog-enic  Nematodes These are soil inhabiting, lethal insect parasitoids These live inside the body of the host, and so they are designated endoparasites. The most commonly studied genera are those that are useful in the biological control of insect pests the Steinernema and Heterohabditis .

18. Advantages  The biological control agents are environmentally friendly and cause no side effects. Decrease disease intensity. Safe for the users and the farming community. Provide natural long term immunity to crops and soil. Play a key role in integrated management of diseases. Reduce undesirable effects from chemical pesticide. Easily available, easy to use and is effective throughout the season.

19. Disadvantages Deleterious effects on non-target microorganisms. Pathogens may develop resistance to the biocontrol agent. Seasonal/weather phenomena can make biocontrol agent ineffective. It affects the product quality. Pest is not completely destroyed by these biological control agents. It is effective only for large scale.

20. Conclusion "Biological control" or "biocontrol" is a process of controlling pests such as "mites, insects, weeds and plant diseases" using some other animals.  Biological control agents offer an eco-friendly and economic alternative to use of toxic chemicals for control of various parasites. Biological control can have side-effects on biodiversity through attacks on non-target species by any of the same mechanisms, especially when a species is introduced without thorough understanding of the possible consequences.

21. References https://en.wikipedia.org/wiki/Biological_pest_control https://hicare.in/blog/different-types-biological-pest-control-agents/ http://www.biocomes.eu/ https://www.cabi.org/what-we-do/invasive-species/biocontrol/ https://www.slideshare.net/ravindra43/bio-control-agent

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