Insecticide is a toxin that helps kill insects. Insecticides prepared with the help of chemicals are mainly used to kill insects and spiders. Insect eggs and larvae are also destroyed by its application. It is applied in medical , industrial and household activities including agriculture . In the twentieth century, the use of pesticides as a major regulator in agricultural production is thought to have spread. [1] In addition, almost all types of pesticides used are thought to have had a profound effect on later biodiversity. Many types of pesticides are also harmful to humans. Some pesticides have also affected the food chain. Nicotine , neem extract is used against naturally occurring insecticides. Nicotine-based pesticides are still used globally , including in the United States and Canada. However , the use of such pesticides has been banned in European Union countries .