Also Called: pyrethrins; 2-methyl-4-oxo-3-(penta-2,4-dienyl)cyclopent-2-enyl [1R-[1.alpha.[S*(Z)](3.beta.)-3-(3-methoxy-2-methyl-3-oxoprop-1-enyl)-2,2-dimethylcyclopropanecarboxylate; Pyrethrum;Pyrethrins and Pyrethroids;Pyrethrin;Pyrethrins and Pyrethroids A complex substance which may be obtained by extraction of chrysanthemum flowers or may be made synthetically. Composed primarily of four esters of chrysanthemumcarboxylic acid (mono and di). They are pyrethrin I and II and cinerin I and II.;Pyrethrins and Pyrethroids A complex substance which may be obtained by extraction of chrysanthemum flowers or may be made synthetically. Composed primarily of four esters of chrysanthemumcarboxylic acid (mono and di). They are pyrethrin I and II and cinerin I and II.;SYNTHETIC PYRETHROIDS;ไพเรธริน;Pyrethrins (ISO);PIRETRUM;除虫菊酯;Pyrethrum (free of sensitizing lactones);Pyrethrum (purified of sensitising lactones)