Identifying circumstances under which high insecticide dose increases or decreases resistance selection

Area of Science:

• Agricultural Entomology
• Population Genetics
• Pest Management

Background:

• Insecticide resistance management is crucial for sustainable agriculture.
• High-dose insecticide application is a proposed strategy to slow resistance evolution.
• The effectiveness of high-dose strategies varies depending on pest characteristics.

Purpose of the Study:

• To evaluate when high-dose insecticide application is an effective resistance management strategy.
• To identify key insect pest traits influencing the optimal insecticide dose for resistance management.
• To compare the impact of high-dose versus low-dose strategies on resistance allele frequency.

Main Methods:

• Development of a flexible deterministic population model for insect pests.
• Inclusion of various life-history traits (reproduction, genetics, life cycle).
• Simulation of insecticide application scenarios to assess resistance selection.

Main Results:

• High immigration can suppress resistance, and this effect often persists even with reduced insecticide doses.
• Reducing insecticide dose generally slows resistance development.
• Exceptions exist where reduced doses accelerate resistance, particularly with high immigration, recessive resistance, and high efficacy.

Conclusions:

• The optimal insecticide dose for resistance management is pest-specific and depends on ecological and genetic factors.
• Careful consideration of pest biology and population dynamics is necessary for effective resistance management strategies.
• Reduced insecticide doses can be beneficial but require careful evaluation to avoid unintended acceleration of resistance.