ABSTRACT
A series of novel O,O-Dialkyl-2-[3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carbonyloxy](aryl) methy-lphosphonates I-1–14 were designed and synthesized. The structures of all the title compounds were confirmed by 1H-NMR, 13C-NMR, 31P-NMR, IR and elemental analysis. Their insecticidal activities against Mythimna separata and Plutella xylostella were evaluated. The results of bioassays indicated that the title compounds exhibited 20–80% larvicidal activity against Mythimna separata at 1000 mg/L.