Biocontrol Agents: Overview, Types, Merits and Demerits

Edited By Irshad Anwar | Updated on Jul 02, 2025 05:23 PM IST

Biocontrol achieves pest-free fields. It is very effective for permanently removing invasive plants. This method employs living organisms to eradicate weeds, pests, insects, pathogens, and other living organisms. Biocontrol Agents are one of the topics in Biology and they carry a weightage of 4% in NEET and 4-5% in CBSE and other Paramedical Exams.

This Story also Contains

What are Biocontrol Agents?
Types Of Biocontrol Agents
Characteristics of Biocontrol Agents
Various Biocontrol Agents
Types of Questions Asked from Biocontrol Agents
Tips, Tricks, and Strategies for Biocontrol Agents

What are Biocontrol Agents?

Biocontrol agents prevent pests or insects from reproducing by using their natural enemies. Biological control is the process by which biocontrol agents operate.

The use of naturally occurring strains of any microorganisms or genetically modified organisms to reduce the frequency or severity of diseases caused by plant pathogens is known as a "biocontrol agent" (BCA). Some Basic facts about biocontrol agents are discussed below:

Biocontrol is the use of a living organism or biological agent to stop the growth of an insect or other pest.
The biocontrol agents defend plants from pests, parasites, predators, and other natural enemies.
They aid in reducing plant pest infestations caused by weeds, nematodes, insects, and mites.
The biological control agents target harmful organisms only, and they leave the beneficial organisms in the soil alone.

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Types Of Biocontrol Agents

Two categories of biological control exist:

Classical biocontrol (Importation)
Inductive Biocontrol (Augmentation)

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Type of Biocontrol Agents	Explanation	Examples
Classical biocontrol agents	This involves prey predators like organisms who control pests in a natural and organic way. This is the relationship between plants and animals present naturally in the environment.	Moths, Parasitic insects, Baculovirus and Aphids.
Inductive biocontrol agents.	The process utilizes pathogens to control the pest and improve the growth of the plant by killing the harmful ones present.	Nematodes

Characteristics of Biocontrol Agents

Some Basic Characteristics of Biocontrol Agents are discussed below:

It is a natural way to manage insects, weeds, pests, and other living things that hinder growth. It is applied to raise crop production and yield.
Predation and parasitism are the basic biological control principles. Trichoderma, Baculoviruses, and Nucleopolyhedrovirus are a few of the microbes used as biocontrol agents.
Farmers use biocontrol agents to kill only undesirable organisms that afflict plants with disease because chemical fertilizers can occasionally kill the desired and necessary soil organisms.
Pest management and the life cycle of the pest are necessary to understand how to approach the biological control process.
Spraying a plant with BT solution made from seeds will kill the caterpillars of butterflies.
Toxins from the worms' intestines are released by the dried seeds, killing them.

Various Biocontrol Agents

Examples of biological pest control agents are provided below:

Biocontrol Agents	Explanation	Examples
Fungi	This is a biological method of pest control which is effective against best like green peach aphids.	Entomophagous Fungi
Predators	These are free-living organisms which consume their prey throughout their lives. It is most effective against those pests who feed upon the crops.	Spiders, Dragonflies and Lacewings
Bacteria	Certain bacteria from the Cocobaccilus family infect the digestive tract of the pest insect. This is natural yet one of the most effective biocontrol methods.	Coccobacillus species
Virus	Viruses such as specific best are being developed to control them selectively without affecting the non-target organisms.	Under development
Parasitoids	Parasitoids lay eggs inside the host and their larva is used as a food source for the host. This eventually kills the host and the entire process acts as a biocontrol process.	Parasitic wasps

Types of Questions Asked from Biocontrol Agents

During exam preparation, different types of questions about the Biocontrol Agents are asked. The table below contains the different patterns of questions asked in different exams.

Exam Type	Types of Questions Asked	Weightage
CBSE	Characteristics of biocontrol agents (fungi, bacteria, viruses, predators, parasitoids). Examples of biological control agents (fungi, predators, parasitoids). Advantages of biocontrol over chemical methods (eco-friendliness, sustainability). Classical vs inductive biocontrol (definitions and examples).	4%
NEET	Mechanisms of biocontrol (prey-predator relationships, parasitism, pathogenic effects on pests). Orders of biological control agents (entomopathogenic fungi, bacteria like Bacillus thuringiensis). Role of biocontrol in integrated pest management (IPM). Hormonal regulation and genetic factors involved in biocontrol agents.	4%
Paramedical	Medical importance of biocontrol agents (e.g., fungi producing bioactive compounds, antibacterial bacteria). Use of biocontrol agents in disease control (e.g., viruses targeting insect vectors). Environmental significance of biocontrol (reducing pesticide use, improving biodiversity). Conservation concerns related to biocontrol agents (non-target effects, resistance development).	3%

Tips, Tricks, and Strategies for Biocontrol Agents

It takes effort to remember everything in a single go. We made the entire problem easy. Some of the tricks regarding Biocontrol Agents are given below which you can use to memorize the important points.

Types of Biocontrol Agents

"FPBVP: Fungi, Predators, Bacteria, Virus, Parasitoids"
F: Fungi (e.g., entomophagous fungi to control aphids)
P: Predators (e.g., spiders, dragonflies, lacewings)
B: Bacteria (e.g., Bacillus thuringiensis for pest control)
V: Virus (host-specific viruses targeting pests)
P: Parasitoids (e.g., parasitic wasps laying eggs in host insects)

Categories of Biocontrol

"CI: Classical, Inductive"
C: Classical biocontrol (prey-predator relationships, using natural enemies)
I: Inductive biocontrol (augmentation, using pathogens like nematodes)

Advantages of Biocontrol

"LESS: Low-risk, Eco-friendly, Sustainable, Specific"
L: Low-risk to human health and environment
E: Eco-friendly (minimizes chemical pesticide use)
S: Sustainable over long periods
S: Specific (targets only the pest)

Steps in Biocontrol Implementation

"ISAT: Introduction, Selection, Application, Testing"
I: Introduction of biocontrol agents
S: Selection of suitable agents for specific pests
A: Application in the field (release of agents)
T: Testing for effectiveness and monitoring progress

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Antibiotic Definition	Biofuel
biofertilizers	Biogas
Biological agents	Restriction Enzyme

Frequently Asked Questions (FAQs)

1. How does biocontrol work?

Biocontrol, also known as biological control, is the practice of eradicating and managing pests, insects, and other pathogens through the use of these organisms' biological enemies.

2. What are the benefits and drawbacks of using biocontrol agents?

The benefits include being environmentally friendly, preventing soil pollution, and not harming people or other beneficial soil organisms.

The drawback of using biocontrol agents is that they do not completely eradicate the pest. Farmers are not knowledgeable about the techniques. They only work for long-term cultivation and may affect the quality of the crops.

3. Does the fungus have the potential as a biocontrol agent?

Using the fungus as a biocontrol agent is possible. They have proven to be a more affordable alternative to dangerous chemical pesticides, though they don't harm the environment.

4. What Kinds Of Agents For Biocontrol Exist?

There are many different types of biocontrol agents, each with advantages and disadvantages. Predators are creatures that eat insects, including free-living species. Lady Beetles are an illustration of this group.

5. When should you employ biological control?

Therefore, the purpose of biological controls is to reduce pest populations to harmful or intolerable levels. People import, augment, conserve, and/or encourage these organisms in their gardens, greenhouses, or farms to help control pests in three different ways.

6. How do biocontrol agents differ from chemical pesticides?

Biocontrol agents are living organisms or natural substances that target specific pests, while chemical pesticides are synthetic compounds that often affect a broader range of organisms. Biocontrol agents typically have fewer environmental impacts, lower risk of pest resistance, and can be self-sustaining in the ecosystem.

7. How do microbial biocontrol agents differ from macro-organisms in pest control?

Microbial biocontrol agents (e.g., bacteria, fungi, viruses) typically work by infecting pests or producing toxic compounds, while macro-organisms (e.g., predatory insects, mites) physically consume or parasitize pests. Microbials can often be mass-produced and applied like pesticides, while macro-organisms usually require more careful handling and release strategies.

8. What are the main advantages of using biocontrol agents?

The main advantages of biocontrol agents include:

9. How do biocontrol agents contribute to sustainable agriculture?

Biocontrol agents contribute to sustainable agriculture by:

10. What are the potential drawbacks of biocontrol agents?

Potential drawbacks of biocontrol agents include:

11. What are the main types of biocontrol agents?

The main types of biocontrol agents are:

12. What is classical biological control?

Classical biological control involves the introduction of a natural enemy from a pest's native range into a new area where the pest has become problematic. This method aims to establish a long-term balance between the pest and its natural enemy, providing ongoing control without repeated interventions.

13. How does augmentative biological control differ from classical biological control?

Augmentative biological control involves the periodic release of mass-reared natural enemies to boost their populations in the field. Unlike classical biocontrol, which aims for long-term establishment, augmentative control often requires repeated releases. It can be inundative (large releases for immediate control) or inoculative (smaller releases aiming for population build-up over time).

14. What is conservation biological control?

Conservation biological control focuses on protecting and enhancing existing populations of natural enemies in an ecosystem. This approach involves modifying the environment or management practices to favor beneficial organisms, such as providing habitat, alternative food sources, or reducing practices that harm natural enemies.

15. How do biocontrol agents contribute to integrated pest management (IPM)?

Biocontrol agents are a key component of integrated pest management (IPM) by:

16. What is the role of parasitoids in biocontrol?

Parasitoids, typically wasps or flies, lay their eggs in or on host pests. When the eggs hatch, the larvae feed on the host, eventually killing it. This process helps control pest populations by reducing their numbers and reproductive capacity. An example is the use of Trichogramma wasps to control caterpillar pests in various crops.

17. What are some examples of herbivorous biocontrol agents?

Herbivorous biocontrol agents are used to control invasive plant species. Examples include:

18. How do predatory biocontrol agents work?

Predatory biocontrol agents work by directly hunting and consuming pest species. They help reduce pest populations by feeding on them at various life stages. For example, ladybugs are used to control aphids in crops by eating both adult aphids and their eggs.

19. How do pathogenic biocontrol agents function?

Pathogenic biocontrol agents are microorganisms (bacteria, viruses, fungi) that cause diseases in pest species. They infect the pest, multiply within it, and ultimately kill or weaken it. For instance, Bacillus thuringiensis (Bt) is a bacterium used to control various insect pests by producing toxic proteins that disrupt their digestive systems.

20. How do competitive biocontrol agents work?

Competitive biocontrol agents work by outcompeting pest species for resources such as food, space, or nutrients. This competition reduces the pest's ability to thrive and reproduce. For example, some beneficial fungi are used to colonize plant roots, preventing harmful fungi from establishing themselves.

21. What are biocontrol agents?

Biocontrol agents are living organisms or natural substances used to control pests, diseases, or unwanted species in agriculture and ecosystems. They work by exploiting natural relationships between organisms, such as predation, parasitism, or competition, to reduce the population of harmful organisms without relying on synthetic chemicals.

22. What is the concept of "host specificity" in biocontrol?

Host specificity refers to the degree to which a biocontrol agent targets only the intended pest species. Highly host-specific agents are preferred as they minimize risks to non-target organisms. Researchers extensively study an agent's host range before its introduction to ensure it won't harm beneficial or native species in the new environment.

23. What is the "tritrophic interaction" in biological control?

Tritrophic interaction refers to the relationship between three trophic levels: the plant (first trophic level), the herbivorous pest (second trophic level), and the natural enemy or biocontrol agent (third trophic level). Understanding these interactions is crucial for effective biocontrol, as plants can influence both pests and their natural enemies through various mechanisms like chemical signaling or providing food and shelter.

24. How do biocontrol agents impact biodiversity?

Biocontrol agents can impact biodiversity in several ways:

25. What is the concept of "establishment" in biological control?

Establishment refers to the ability of a biocontrol agent to survive, reproduce, and maintain its population in the new environment where it's introduced. Successful establishment is crucial for long-term pest control, especially in classical biological control. Factors affecting establishment include climate compatibility, availability of suitable hosts, and absence of hyperparasitoids or predators of the biocontrol agent.

26. How can genetic engineering be used to enhance biocontrol agents?

Genetic engineering can enhance biocontrol agents by:

27. What are some challenges in the commercial production of biocontrol agents?

Challenges in commercial production of biocontrol agents include:

28. What is the role of modeling in biological control research and implementation?

Modeling plays several important roles in biological control:

29. How do biocontrol agents interact with pesticides in agricultural systems?

Interactions between biocontrol agents and pesticides can be complex:

30. How does climate change impact the use of biocontrol agents?

Climate change can affect biocontrol agents in several ways:

31. What are the economic considerations in implementing biological control?

Economic considerations in biological control include:

32. What are some ethical considerations in the use of biocontrol agents?

Ethical considerations in biocontrol include:

33. How do environmental factors affect the efficacy of biocontrol agents?

Environmental factors such as temperature, humidity, light, and soil conditions can significantly impact biocontrol agents' survival, reproduction, and effectiveness. For example, many predatory mites require specific humidity levels, while some microbial agents are sensitive to UV light. Understanding these requirements is crucial for successful implementation of biocontrol strategies.

34. What role do pheromones play in biological control?

Pheromones, chemical signals used for communication within species, play several roles in biological control:

35. How does the concept of "ecological fitting" apply to biocontrol agents?

Ecological fitting refers to the process by which a species can persist in a new environment by relying on pre-existing adaptations, rather than evolving new traits. In biocontrol, this concept is important when selecting agents, as it suggests that effective control might be achieved by introducing natural enemies that are pre-adapted to the target pest and the new environment, even if they don't share an evolutionary history with the specific pest population.

36. What is the concept of "banker plants" in biological control?

Banker plants are non-crop plants used to support populations of beneficial insects in agricultural systems. They work by:

37. What are some emerging technologies in the field of biological control?

Emerging technologies in biological control include:

38. How do biocontrol agents affect ecosystem services?

Biocontrol agents can influence ecosystem services in several ways:

39. What is the concept of "apparent competition" in biological control?

Apparent competition occurs when two species that don't directly compete are negatively affected by sharing a common natural enemy. In biocontrol, this can happen when:

40. How do biocontrol agents adapt to new environments over time?

Biocontrol agents can adapt to new environments through:

41. How does the concept of "functional biodiversity" relate to biological control?

Functional biodiversity refers to the variety of ecological roles performed by different species in an ecosystem. In biological control:

42. How do biocontrol agents interact with plant defense mechanisms?

Biocontrol agents can interact with plant defense mechanisms in several ways: