杀虫剂(insecticide)
用来杀死昆虫的有毒物质。主要用於控制侵扰作物的害虫或者在特定地区消灭传染疾病的昆虫。无机的杀虫剂包括了砷、铅和铜的化合物。有机的杀虫剂可能是天然的，如鱼藤酮、除虫菊和尼古丁（参阅toxin）；或是合成的，如氯代烃类（例如，滴滴涕、狄氏剂、林丹）、氨基甲酸酯，与尿素有关（如氨基甲醯、灭多虫和卡甲喃）、巴拉松、有机磷酸盐（或酯）。昆虫的激素被认为是另一种不同的种类。杀虫剂可影响到神经系统，抑制重要的或防止幼体成熟（例如保幼激素）。有的是胃毒剂，有的是吸入性的毒剂，而其他则是接触性的毒剂。类似机械用的油可阻断呼吸孔。杀虫剂造成的改变不止是对特定的昆虫（可能会早造成抗药性），同时也会毒害非特定的昆虫和对环境造成影响；最坏的杀虫剂（如DDT）便遭禁用。
English version：
insecticide
Any substance used to kill insects. Such substances are used mainly to control pests that infest cultivated plants and crops or to eliminate disease-carrying insects in specific areas. Inorganic insecticides include arsenic, lead, and copper compounds. Organic insecticides may be natural, like rotenone, pyrethrins, and nicotine (see toxin), or synthetic, like chlorinated hydrocarbons (e.g., DDT, dieldrin, lindane); carbamates, related to urea (e.g., carbaryl, carbofuran); and parathions, organic phosphorus esters. Insect hormones may be considered a separate class. Insecticides may affect the nervous system, inhibit essential enzymes, or prevent larvae from maturing (e.g., juvenile hormone). Some are stomach poisons, some inhalation poisons, and others contact poisons. Agents like dormant oils act mechanically, simply blocking the breathing pores. Insecticides vary widely not only in effectiveness against target insects (which may develop resistance) but also in toxicity to nontarget species (including humans) and environmental effects; the worst (e.g., DDT) have been banned.