Question

Insecticide resistance can be avoided by

• A. Frequent change of insecticides
• B. Continuous use of same insecticide for a long time
• C. Change of group of insecticides
• D. Use of higher doses of insecticides

Hint:

Resistance Management: Always rotate DIFFERENT CHEMICAL GROUPS MODES OF ACTION (e.g., Pyrethroid $\leftrightarrow$ Organophosphate $\leftrightarrow$ Macrocyclic Lactone).

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Integrated pest management (IPM) prevents selection of resistant insect biotypes by rotating chemical classes with distinct modes of action.

Step 2: Detailed Explanation:
Principles of insecticide resistance management (IRM):
- Repeated use of insecticides within the same chemical class selects for target-site point mutations (e.g., $kdr$ mutation for pyrethroids) or upregulated metabolic detoxification enzymes (cytochrome P450s, esterases).
- Merely switching commercial brands within the same class (or increasing doses) accelerates cross-resistance.
- The definitive strategy is rotating across completely different chemical groups modes of action (e.g., rotating Organophosphates $\rightarrow$ Synthetic Pyrethroids $\rightarrow$ Macrocyclic Lactones $\rightarrow$ Neonicotinoids Isoxazolines), disrupting selection pressure.

Step 3: Final Answer:
Hence, insecticide resistance is avoided by Change of group of insecticides, corresponding to option (C).