Pesticide resistance management

Definition

The coordinated set of strategies designed to delay or reverse the evolution of pesticide resistance in pest populations, thereby preserving the efficacy of chemical control agents over time. Approaches include rotating chemistries with different modes of action, applying mixtures or mosaics of unrelated compounds, maintaining untreated refugia to conserve susceptible genotypes, restricting treatment frequency, and integrating non-chemical tactics such as biological control, crop rotation, or host-plant resistance. Efficacy and resistance are inversely related: as resistance increases, pesticide performance declines.

Etymology

From pesticide + resistance + management; the compound emerged in agricultural entomology and resistance genetics literature during the 1980s as integrated approaches replaced reliance on single-tactic chemical control.

Example

In cotton bollworm (Helicoverpa armigera) management, growers may rotate pyrethroids, organophosphates, and Bacillus thuringiensis (Bt) toxins across generations, coupled with planting non-Bt refuge areas, to slow selection for multi-resistant genotypes.

Synonyms

• resistance management
• IRM (insecticide resistance management)

Related Terms

• pesticide resistance
• Mode of action
• refugia
• Integrated Pest Management
• Natural selection
• Cross-resistance
• fitness cost
• resistance monitoring

Usage Notes

Often abbreviated IRM in agricultural contexts, though this can also mean "insecticide resistance management" specifically. Distinguish from IPM (integrated pest management), which encompasses broader ecological and economic optimization; IRM is a component of IPM focused specifically on evolutionary dynamics. The term applies equally to acaricides, fungicides, and herbicides, but in entomological usage typically emphasizes arthropod pests. Refugia strategy—intentionally leaving some hosts untreated—remains controversial in some systems due to economic pressure for complete control.