Overview
Pymetrozine is a pyridine azomethine insecticide developed by Ciba-Geigy (now Syngenta) in the 1990s. It belongs to the chemical class of pyridinecarboxamides and is known for its unique mode of action as a feeding blocker. Unlike neurotoxic insecticides, pymetrozine causes insects to stop feeding within hours of exposure, leading to starvation and death. The compound is highly selective, primarily affecting sap-sucking pests while preserving beneficial insects like pollinators and predator species. This characteristic makes it valuable in integrated pest management (IPM) systems. Its systemic properties allow for both foliar and soil applications, with translocation within plant tissues.
Physical and Chemical Properties
Pymetrozine exhibits stability under normal environmental conditions, with a melting point between 217-220°C. Its low water solubility (0.29 g/L at 20°C) contributes to reduced leaching potential, while moderate solubility in organic solvents like acetone (160 g/L) facilitates formulation into wettable powders or suspension concentrates. The compound demonstrates photostability but may degrade under alkaline conditions (pH >9). Its vapor pressure is negligible (2×10-6 Pa at 25°C), minimizing volatility risks. Technical-grade pymetrozine typically contains 95-98% active ingredient, with impurities primarily consisting of manufacturing byproducts.
Main Applications
Pymetrozine is extensively used against Hemiptera pests, particularly aphids (e.g., Myzus persicae), whiteflies (Bemisia tabaci), and planthoppers (Nilaparvata lugens) in various cropping systems. In rice cultivation, it effectively controls brown planthoppers while being safe for natural enemies like spiders. Field application rates typically range from 50-150 g active ingredient per hectare, depending on pest pressure and crop stage. The compound is often rotated with insecticides having different modes of action (e.g., neonicotinoids, pyrethroids) to delay resistance development. Some formulations combine pymetrozine with synergists or other active ingredients to broaden the pest spectrum.
Safety and Storage
Pymetrozine is classified as WHO toxicity class III (slightly hazardous) with an acute oral LD50 >5,000 mg/kg in rats. However, appropriate personal protective equipment (PPE) including gloves and masks should be worn during handling to prevent irritation or sensitization. Storage requires dry conditions below 30°C, separated from food and feed. Containers should be tightly sealed to prevent moisture absorption. In case of spillage, absorb with inert material and dispose according to local regulations. The compound has low environmental persistence (DT50 <30 days in soil) but should not be applied near aquatic systems due to potential toxicity to aquatic arthropods.
B2B Procurement Guide
When sourcing pymetrozine, verify the supplier's certification (e.g., ISO 9001) and request batch-specific Certificate of Analysis (CoA) detailing purity (≥95%), moisture content (<1%), and impurity profiles. Technical material is commonly packaged in 25kg fiber drums with polyethylene liners. Consider regional regulatory status—pymetrozine is registered in major agricultural markets including the EU (approved until 2025), China, and Brazil, but some countries restrict its use in certain crops. For formulation buyers, inquire about compatible surfactants and stabilizers. Spot prices fluctuate with raw material (e.g., 2-chloro-5-chloromethylpyridine) availability, while contract purchases (≥1MT) typically offer 5-15% discounts.