Insecticide Rotation and Adaptive Fitness Cost Underlying Insecticide Resistance Management for Spodoptera frugiperda...

Area of Science:

• Agricultural Entomology
• Insecticide Resistance Management
• Pest Control

Background:

• Insecticide resistance is a major threat to effective pest control.
• Rotation of insecticide modes of action is a key strategy to delay resistance development.
• Spodoptera frugiperda is a significant agricultural pest globally.

Purpose of the Study:

• To evaluate the efficacy of rotating spinetoram and metaflumizone against Spodoptera frugiperda.
• To determine the impact of insecticide rotation on resistance frequency and biological parameters.
• To compare resistance development under rotation versus sequential exposure.

Main Methods:

• Larvae of Spodoptera frugiperda were exposed to spinetoram, metaflumizone, or a rotation of both for five generations.
• Insecticidal and biological responses were assessed, including fertility life table parameters.
• Resistance frequency and biological characteristics (e.g., development time, longevity) were compared across treatments.

Main Results:

• Continuous exposure to metaflumizone and spinetoram increased resistance frequency by 49.5% and 29.2%, respectively.
• Insecticide rotation significantly reduced resistance frequency by approximately 50%.
• Successive exposure to insecticides resulted in adaptive costs, including delayed development and reduced adult longevity.

Conclusions:

• Rotation of spinetoram and metaflumizone is an effective strategy for managing Spodoptera frugiperda resistance.
• Insecticide rotation mitigates the negative biological impacts associated with resistance development.
• Integrated pest management programs should incorporate insecticide rotation to ensure long-term efficacy.