Diazinon: A Broad-Spectrum Organophosphate Insecticide

Technical Introduction

Diazinon (IUPAC: O,O-diethyl O-(2-isopropyl-6-methylpyrimidin-4-yl) phosphorothioate) is a widely used organophosphate insecticide. It controls a variety of chewing and sucking pests by inhibiting acetylcholinesterase (AChE) in insects, leading to nerve overstimulation and death.

• Mode of Action: Organophosphate acetylcholinesterase inhibitor (IRAC Group 1B).

• Systemicity: Primarily a contact and stomach insecticide; not systemic.

• Target Spectrum: Effective against aphids, leafhoppers, caterpillars, beetles, and other crop pests.

Applications

• Field Crops:

  • Controls aphids, leafhoppers, caterpillars, and beetles in cotton, maize, wheat, and vegetables.

• Fruit Orchards:

  • Applied on apples, citrus, and stone fruits for control of leaf-eating and sucking pests.

• Vegetables:

  • Used on tomatoes, peppers, cucumbers, and cabbage for aphid, whitefly, and caterpillar management.

• Public Health:

  • Sometimes used in mosquito larval control, although less common due to newer alternatives.

Advantages

• Broad-Spectrum Efficacy: Controls chewing and sucking pests across multiple crops.

• Rapid Knockdown: Provides fast reduction in pest populations.

• Flexible Formulations: Available as emulsifiable concentrates (EC), wettable powders (WP), and granules (GR).

• Cost-Effective: Proven efficacy at moderate application rates.

• Established Usage: Long history of agricultural and pest control use worldwide.

Specifications (Typical Parameters)

FAQ

Q1: How does Diazinon kill pests?
A: It inhibits acetylcholinesterase, leading to nerve overstimulation, paralysis, and death in insects.

Q2: Is Diazinon systemic?
A: No. It works primarily through contact and ingestion, not via systemic movement in plants.

Q3: Can Diazinon be used on vegetables and fruits?
A: Yes, it is effective on vegetables, fruit trees, and field crops, but users must follow pre-harvest intervals.

Q4: Is Diazinon safe for beneficial insects?
A: No. It is toxic to bees, natural enemies, and aquatic organisms, so careful application timing is required.

Q5: Can Diazinon be integrated into IPM programs?
A: Yes, but rotation with other modes of action is recommended to prevent resistance and reduce non-target impact.