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Subject: Biology
Semester: 2
Period: 4
Week: 23
School Name:
Teacher’s Name:
Subject: Biology
Grade Level: Grade 10
Date: Week 23
Lesson Duration: 45 minutes
Week & Term: Week 23, Period 4
Topic: Arthropods and Biological Control of Pests
Sub-topic: Pests – Economic Importance, Chemical Control, and Biological Control
Learning Objectives
By the end of the lesson, students should be able to:
- Define pests and give examples of common pests.
- Explain the economic importance of pests.
- Differentiate between chemical and biological methods of pest control.
- Identify advantages and disadvantages of chemical and biological pest control.
- Discuss ways to minimize the damage caused by pests in agriculture and homes.
Previous Knowledge
Students already know:
- Differences between harmful and useful insects
- General feeding behavior and impact of insects like cockroaches, mosquitoes, and termites
Instructional Materials
- Flashcards showing pest insects (locusts, weevils, aphids, termites)
- Sample insecticide labels
- Chart comparing biological and chemical control
- Poster on integrated pest management
- Real or model crop samples with pest damage (if available)
Lesson Development – ABC Model
A – Anticipation (Warm-up / Starter)
Time: 5–10 mins
Ask:
- “What do you call insects or animals that destroy crops or stored food?”
- “Have you seen someone spraying chemicals on a farm? Why do they do it?”
Get students to brainstorm the term “pest” and where they’ve seen pest damage.
B – Building Knowledge (Main Lesson Body)
Time: 25–30 mins
Teacher explains:
- Definition of Pest: An organism that damages crops, food, clothing, livestock, or property.
- Examples:
- Insects: Grasshoppers, aphids, locusts, termites, weevils
- Animals: Rats, birds, monkeys (in some farming areas)
- Economic Importance:
- Cause crop failure and loss of food
- Reduce farmer income
- Damage stored food and materials (like termites on wood or weevils in grains)
- Control Methods:
- Chemical Control: Using pesticides, herbicides, and insecticides to kill pests
- Advantages: Fast, effective
- Disadvantages: Harm to environment, health issues, pesticide resistance
- Biological Control: Using natural enemies like predators, parasites, or diseases to control pests
- Examples: Ladybugs eat aphids, birds eat locusts
- Advantages: Eco-friendly, long-term
- Disadvantages: Slower, must be well managed to avoid imbalance
Learners’ Activities (Expanded):
- Group project: Sort picture cards of pests into “agricultural” and “domestic” categories.
- In teams, list 5 effects pests can have on food security.
- Class debate: “Chemical control is better than biological control.”
- Use comparison charts to evaluate pros and cons of each pest control method.
- Role play: A farmer seeks advice from a pest control officer about their options.
Assessment Checks:
- True or false quiz: “Biological control is always safer than chemical control.”
- Label pest examples and identify control measures for each.
- Fill-in-the-gap worksheet on pest control methods and economic importance.
Notes (Expanded & Detailed)
Pests can destroy crops, spread disease, damage stored goods, and cause economic hardship. Farmers, market sellers, and even homes suffer losses due to pests. For example, weevils destroy stored rice, while termites damage wood and paper.
To manage pests, humans use chemical methods like spraying insecticides or poisons, which act fast but can pollute the air, soil, and water. Biological methods involve using predators (like birds) or parasites (like bacteria) to reduce pest populations naturally. While slower, this approach is safer for the environment.
In both methods, careful planning is important to avoid side effects like pest resistance, crop contamination, or harming helpful species.
C – Consolidation (Conclusion & Assessment)
Time: 5–10 mins
Teacher asks:
- “Can we eliminate pests totally?”
- “What are the best practices in choosing between chemical and biological methods?”
Students summarize the pros and cons of each method and mention at least one pest they’ve seen.
Evaluation Method (Expanded)
- Written summary: Compare biological and chemical control in two paragraphs.
- Oral presentation: “The pest that troubles my community the most.”
- Quiz: Match pests to control methods and economic damage they cause.
Assignment (Expanded)
- Interview a farmer, shopkeeper, or parent: “What pests do they face and how do they deal with them?” Write a short report.
- Draw a poster warning people about pest control mistakes (e.g., overuse of chemicals).
- Write five differences between chemical and biological pest control.
Follow-up Activity (if any)
Students will monitor their school environment for signs of pests and suggest appropriate control methods.
Differentiation / Inclusive Strategies
- Struggling Learners: Provide pest-control examples in story format
- Advanced Learners: Research integrated pest management (IPM) systems
- Students with Disabilities: Provide picture-based worksheets and audio summaries
Teacher’s Reflection (After Class)
• What worked well?
• What needs improvement?
• Students’ engagement level: □ High □ Medium □ Low
• Next steps: Review and reinforce Period 4 topics in preparation for assessment