Pirimiphos-methyl – A Potent Systemic Insecticide for Pest Control

Discover Pirimiphos-methyl – an organophosphate insecticide with systemic, contact, and stomach action. Highly effective against weevils, aphids, flies, mosquitoes, and storage or crop pests.

Table of Contents

1. What is Pirimiphos-methyl?
2. Mode of Action on Insects
3. Practical Applications in Agriculture and Grain Storage
4. Key Advantages of Pirimiphos-methyl
5. Pest Spectrum: Which Insects Can It Eliminate?
6. Proper Usage and Recommended Dosage
7. Popular Products Containing Pirimiphos-methyl
8. Important Safety Notes
9. Conclusion

1. What is Pirimiphos-methyl?

Pirimiphos-methyl is an organophosphate insecticide with strong systemic, contact, and stomach poisoning effects. It is widely used in agriculture and post-harvest storage to control a wide range of insect pests.

• Molecular formula: C₁₁H₂₀NO₅PS
• Chemical group: Organophosphates
• Common formulations: EC (Emulsifiable Concentrate), DP (Dust Powder), ME (Micro-emulsion)
• Properties: Slight volatility, long-lasting effect, suitable for both foliar spraying and residual treatments

2. Mode of Action on Insects

Pirimiphos-methyl inhibits the cholinesterase enzyme in the insect nervous system, disrupting nerve transmission – causing convulsions, paralysis, and death.

• Acts quickly upon contact or ingestion
• Penetrates the insect cuticle and moves systemically through plant tissue
• Offers residual activity on treated surfaces

3. Practical Applications in Agriculture and Grain Storage

In agriculture:

• Controls aphids, leaf-feeding caterpillars, fruit flies, leaf folders, thrips
• Applicable for crops like rice, maize, vegetables, fruits, tea, coffee

In grain storage:

• Kills storage pests like rice weevils, bean weevils, maize weevils, tobacco beetles
• Used via surface spraying or fumigation for rice, maize, coffee, seeds, and grain stock
• Recommended by FAO and WHO for warehouse pest control

4. Key Advantages of Pirimiphos-methyl

• ✅ Excellent systemic activity, quickly absorbed into plant tissue
• ✅ Dual action: contact + stomach poison for effective pest control
• ✅ Long residual effect, especially in warehouse or structural treatments
• ✅ Suitable for Integrated Pest Management (IPM) and active ingredient rotation
• ✅ Can also be used for public health vector control (mosquitoes, flies, cockroaches)

5. Pest Spectrum: Which Insects Can It Eliminate?

6. Proper Usage and Recommended Dosage

In crop production:

• Pirimiphos-methyl 500EC: 15–25 ml per 16 liters of water
• Apply early when insects appear; observe a 7–10 day pre-harvest interval
• Spray evenly on the foliage, especially areas where pests hide (undersides of leaves)

In warehouse storage:

• Use DP or ME formulations for residual treatment
• Recommended dosage: 1–2 g/m² of storage area
• Apply on walls, floors, bags, or directly on stored grains before sealing

7. Important Safety Notes

• Do not mix with highly alkaline or copper-based products
• Always wear protective gear; avoid contact with skin, eyes, or mouth
• Do not use near aquatic systems, ponds, or fish farms
• Avoid using on flowering crops or during pollination periods
• Rotate with other active ingredients to prevent resistance development

8. Conclusion

Pirimiphos-methyl is a broad-spectrum, high-efficacy insecticide, suitable for use in crop fields, orchards, and grain storage facilities. With its strong systemic properties, dual-action mode, and wide pest coverage, it remains a trusted choice for modern farmers and post-harvest managers seeking reliable insect control solutions.