Resistance Management
Strategies to prevent or delay pest populations from developing resistance to pesticides through product rotation and MoA diversity.
Detailed Overview
Pesticide resistance occurs when repeated use of the same chemistry selects for individuals that survive treatment, eventually creating resistant populations. Bed bugs have developed widespread resistance to pyrethroids. German roaches show resistance to various insecticide classes. The solution: rotate products with different modes of action. Do not rotate between products in the same chemical class (all pyrethroids have same MoA regardless of active ingredient). Use IRAC/RRAC group numbers to identify different MoAs. Establish rotation schedules: use Product A (MoA 3) for 6-12 months, switch to Product B (MoA 4) next period, then Product C (MoA 28). Combine chemistry with non-chemical methods to reduce selection pressure. Use tank mixes of products with different MoAs for high-resistance risk pests. Monitor treatment effectiveness - declining control may signal developing resistance. Desiccant dusts and heat treatments cannot be resisted because they use physical mechanisms. When resistance suspected, switch to different MoA class immediately and increase non-chemical controls.
When to Use
Implement rotation programs for all accounts, especially those requiring frequent treatments. Rotate MoA groups annually minimum. Switch immediately if declining control suggests resistance developing.
Required Skill Level
Should only be performed by licensed pest management professionals
Benefits
- Extends useful life of effective products
- Prevents resistance development in pest populations
- Maintains treatment effectiveness long-term
- Reduces callbacks from treatment failures
- Provides alternative options when resistance occurs
Limitations
- Requires tracking which products used at each account
- Limited products available in some MoA classes
- Costs may vary between products in rotation
- Resistance may already exist in local populations
- Requires ongoing education about new products and MoAs
Related Concepts
Other principles that may be useful
Integrated Pest Management (IPM)
A prevention-based pest management method that provides long-lasting pest control, improves building conditions, and is less harmful to residents and pets than traditional pest control.
Pest Triangle
The four essential requirements pests need to survive: food, water, shelter, and ways to get around. Eliminating any of these makes an environment inhospitable to pests.
Threshold Levels
The point at which pest populations or damage reaches a level that requires action. IPM uses threshold levels to determine when treatment is necessary rather than treating on a schedule.