The competition for crops between humans and insects is as old as agriculture, but chemical warfare against insects has a much shorter history. Farmers began to use chemical substances to control pests in the mid-1800s. Not surprisingly, the development of insecticides paralleled the development of chemistry: early insecticides were in the main inorganic and organic arsenic compounds, followed by organochlorine compounds, organophosphates, carbamates, pyrethroids, and formamidines, many of which are in use today. In 2001, global sales of chemical insecticides included more than 1.23 million pounds of active ingredients and reached about $9.1 billion a year.

There are disadvantages to relying exclusively on chemical pesticides. Foremost is that widespread use of single-chemical compounds confers a selective evolutionary advantage on the progeny of pests that have acquired resistance to the substances.