Dichlorvos (DDVP): A Broad-Spectrum Organophosphate Insecticide

Technical Introduction

Dichlorvos, also known as DDVP (2,2-dichlorovinyl dimethyl phosphate), is a volatile organophosphate insecticide widely used for pest control in agriculture, stored products, livestock, and public health.

Its mode of action is through inhibition of acetylcholinesterase (AChE), the enzyme responsible for breaking down acetylcholine in nerve synapses. The accumulation of acetylcholine overstimulates the nervous system, leading to paralysis and death of the insect.

Unlike some organophosphates, Dichlorvos is characterized by its high volatility, making it especially effective as a fumigant insecticide in enclosed spaces.

Applications

Agriculture (Crops):
- Controls a broad range of chewing and sucking insects, including aphids, leaf miners, thrips, caterpillars, and beetles.
- Often used in vegetables, fruits, rice, maize, and ornamentals.
Stored Grain Protection:
- Prevents infestations of weevils, beetles, and moth larvae in storage facilities.
- Commonly applied as a grain protectant and space fumigant.
Public Health:
- Used in aerosol sprays, foggers, mosquito coils, and impregnated strips to control flies, mosquitoes, cockroaches, and other household pests.
Livestock & Veterinary Applications:
- Controls lice, fleas, and flies in animal housing.
- Sometimes incorporated into ear tags, sprays, and dips for livestock.
Industrial & Domestic Use:
- Found in insecticidal strips and aerosols for fly and mosquito control in kitchens, warehouses, and food storage areas.

Advantages

Broad-Spectrum Insect Control: Effective against many flying, crawling, and stored-product pests.
Fumigant Action: Volatile nature ensures penetration into enclosed spaces for long-lasting control.
Rapid Knockdown: Quickly paralyzes and kills target insects after exposure.
Multiple Applications: Can be used in agriculture, storage, livestock, and domestic pest management.
Cost-Effective: Inexpensive compared to many modern insecticides.

Specifications (Typical Parameters)

Parameter	Description	Typical Value
Chemical Name	2,2-dichlorovinyl dimethyl phosphate	Dichlorvos (DDVP)
Chemical Formula	Molecular composition	C₄H₇Cl₂O₄P
Molecular Weight		~220 g/mol
Appearance	Physical state	Colorless to pale yellow liquid
Odor		Mildly sweet, chemical odor
Purity (TC)	Technical concentrate	≥ 95%
Mode of Action	Acetylcholinesterase inhibitor → nerve disruption	Contact, fumigant, stomach poison
Volatility	High volatility, fumigant activity	Persists in enclosed spaces
Common Formulations	EC (emulsifiable concentrate), ULV (ultra-low volume), Aerosols, Impregnated strips	50% EC, 76% EC, pest strips
Stability	Decomposes in alkaline medium and under sunlight	Must be stored tightly sealed

FAQ

Q1: What pests is Dichlorvos most effective against?
A: It is highly effective against flies, mosquitoes, cockroaches, moths, beetles, and stored-product pests.

Q2: How is Dichlorvos applied in stored grain protection?
A: It is used as a fumigant and grain protectant, either as a direct treatment or through controlled-release strips in storage facilities.

Q3: Is Dichlorvos systemic in plants?
A: No, unlike Trichlorfon, Dichlorvos acts mainly as a contact, stomach, and fumigant insecticide, not systemic.

Q4: Is Dichlorvos safe for humans and livestock?
A: Dichlorvos is toxic to humans and animals if mishandled. Proper protective equipment and adherence to safety guidelines are critical. Many countries have restricted or banned its use due to health risks.

Q5: Why is Dichlorvos still used despite safety concerns?
A: It remains popular in developing regions due to its low cost, quick knockdown effect, and fumigant properties, although safer alternatives are recommended.

Q6: How does Dichlorvos differ from Trichlorfon?
A:

Dichlorvos (DDVP): Volatile, acts as a fumigant/contact insecticide; not systemic.
Trichlorfon: Less volatile, shows systemic activity in plants and veterinary deworming applications.