C
CraftExam
medium difficulty6 min

Microbes as Biocontrol Agents

Microbes as biocontrol agents are beneficial microorganisms or microbial products used to control pests and plant diseases in a targeted and ecologically safer way.

In one line: Biocontrol means biological control: use a living agent or its product against a pest.

Concept Practice Coming Soon

Understand it

  • Biocontrol uses natural enemies of pests instead of depending only on chemical pesticides.
  • Bacillus thuringiensis produces toxic proteins that can kill specific insect larvae after ingestion.
  • Trichoderma is a free-living fungus found in root ecosystems and is used against several plant pathogens.
  • Baculoviruses are useful because they are usually narrow in host range and can target specific insect pests.
  • This idea is linked with Integrated Pest Management, where biological, cultural and limited chemical methods are combined.
  • CBSE commonly tests specificity, examples and environmental advantage.

Example

Baculoviruses belonging to the nucleopolyhedrovirus group are used against certain insect pests because they can be species-specific, reducing harm to many non-target organisms.

Rule to remember

Key biological rule: effective biocontrol depends on host specificity and ecological balance rather than broad destruction of all organisms.

See it worked out

Follow the example line by line, then use the same method on new questions.

Worked example

  1. 1Question: Give two examples of microbial biocontrol agents.
  2. 2Answer: Bacillus thuringiensis is used against insect larvae, and Trichoderma is used against plant pathogens in root ecosystems.

Method you can reuse

  1. 1Identify the pest or disease problem.
  2. 2Choose a suitable microbial agent such as Bt, Trichoderma or baculovirus.
  3. 3Explain its specific action.
  4. 4Add the ecological advantage of reducing broad chemical pesticide dependence.

Visual tip

No compulsory diagram is required. A simple flow chart can show pest, biocontrol agent and reduced pest damage.

Check yourself

Answer the question in your head before opening the answer.

Try it yourself

Why are baculoviruses considered useful biocontrol agents?

Think first, then show answer
Baculoviruses are useful because many of them infect specific insect pests and have a narrow host range. This makes pest control more targeted and reduces harm to non-target organisms.

Common wrong answer

Chemical pesticides are called biocontrol agents because they control pests.

Don't mix this up

Students often write that biocontrol means killing all insects. It actually aims to manage harmful pests while reducing damage to useful organisms and the ecosystem.

Exam tip

When writing about biocontrol, include one named agent, its target or role, and why it is preferred over indiscriminate pesticide use.

Write it in the exam

Each point is worth about one mark. Write point 1 for a 1-mark question and keep adding points as the marks go up.

How CBSE asks it

Asked as examples, assertion-reason on specificity, advantages over chemical pesticides, or short notes on IPM.

Answer plan

Define biocontrol, name examples such as Bt, Trichoderma or baculovirus, state the target or action, and add the advantage of specificity and reduced chemical load.
  1. 1

    Enough for 1 mark

    Microbes as biocontrol agents are beneficial microorganisms or microbial products used to control pests and plant diseases in a targeted and ecologically safer way.

  2. 2

    Add for 2 marks

    Example: Baculoviruses belonging to the nucleopolyhedrovirus group are used against certain insect pests because they can be species-specific, reducing harm to many non-target organisms.

  3. 3

    Add for 3 marks

    Biocontrol uses natural enemies of pests instead of depending only on chemical pesticides.

Practice

Concept practice is coming soon

Login to access concept-level MCQs and weak-concept practice as they become available.

10 MCQs5 MinutesInstant Results
Login

Help improve this page

Found something confusing, incorrect, or missing?

Open Learning Map