When Chemicals Are Necessary: Safer Choices and Best Practices

While integrated pest management (IPM) prioritizes non-chemical control methods, there are situations where pesticides may be necessary to prevent significant economic, health, or aesthetic damage. When chemical control is warranted, selecting safer products and following best practices minimizes risks to human health, beneficial insects, and the environment. This article provides guidance on choosing appropriate pesticides, understanding labels, and applying them responsibly as part of a comprehensive IPM program.

When Pesticides Are Justified

Pesticides should be considered only when:

• Action Thresholds Exceeded: Pest populations have exceeded established economic, aesthetic, or health thresholds, and other control methods have proven insufficient.
• Rapid Response Needed: Immediate action is required to prevent severe damage or health risks (e.g., disease vectors, structural pests).
• Part of IPM Program: Pesticides are used as one component of a comprehensive IPM program that includes prevention, monitoring, and other control methods.
• Selective and Targeted: The pesticide is selective for the target pest and can be applied in a targeted manner that minimizes non-target impacts.

Selecting Safer Pesticides

When pesticides are necessary, choose the safest effective option:

• Biorational Pesticides: These include botanical insecticides (neem, pyrethrum), insecticidal soaps, horticultural oils, and microbial insecticides (Bacillus thuringiensis, Bt). They are generally less toxic to beneficial insects and break down more quickly in the environment.
• Selective Products: Choose pesticides that target specific pest groups (e.g., Bt for caterpillars) rather than broad-spectrum products that harm beneficial insects.
• Low Toxicity Ratings: Check pesticide labels for toxicity ratings. Products with "Caution" are generally less toxic than those with "Warning" or "Danger."
• Avoid Systemic Pesticides: Systemic pesticides (like neonicotinoids) are absorbed by plants and can persist in tissues, potentially harming pollinators and other beneficial insects long after application.

Best Practices for Pesticide Application

Proper application minimizes risks and maximizes effectiveness:

• Read and Follow Labels: Pesticide labels contain legally binding instructions for safe and effective use. Follow all directions, including application rates, timing, and safety precautions.
• Timing: Apply pesticides when pests are most vulnerable (often early life stages) and when beneficial insects are least active (early morning or late evening). Avoid applications during bloom when pollinators are active.
• Targeted Application: Apply only to affected areas rather than blanket treatments. Use spot treatments when possible.
• Weather Conditions: Avoid applications during windy conditions (drift risk) or when rain is expected (reduced effectiveness, runoff risk).
• Protective Equipment: Wear appropriate personal protective equipment (PPE) as specified on the label.

Minimizing Non-Target Impacts

Protect beneficial insects and the environment:

• Protect Pollinators: Avoid applications to flowering plants. If necessary, apply when flowers are closed (early morning or evening) and when pollinators are inactive.
• Preserve Beneficial Insects: Use selective pesticides and avoid broad-spectrum products. Provide refuges (untreated areas) where beneficial insects can survive.
• Prevent Runoff: Avoid over-application and prevent pesticides from reaching water sources through runoff or drift.
• Rotate Products: Rotate between different pesticide classes to reduce the risk of resistance development.

When pesticides are necessary, selecting safer products and following best practices minimizes risks while achieving effective pest control. By using pesticides judiciously as part of a comprehensive IPM program, we can manage pests effectively while protecting human health, beneficial insects, and environmental quality.