Pesticide Classification - Mode of Action: Pesticides are grouped primarily by

• A. Their source
• B. How they destroy or control the pest
• C. Their color
• D. Their cost

Answer: (B)

Pesticides are grouped primarily by how they destroy or control the pest—their mode of action. This means classification is based on the specific process the chemical disrupts in the pest, such as disrupting the nervous system, inhibiting energy production, interfering with development, or blocking essential physiological functions. This way of grouping is essential for resistance management: rotating products with different modes of action helps prevent pests from adapting and developing resistance. Grouping by source, color, or cost doesn’t reveal how the product works or how to design effective rotation or combination strategies, so it’s much less useful for practical management.