Insecticides are pesticides used to kill insects. They include ovicides and larvicides used against insect eggs and larvae, respectively. Acaricides, which kill mites and ticks, are not strictly insecticides, but are usually classified together with insecticides. The major use of Insecticides is agriculture, but they are also used in home and garden, industrial buildings, vector control and control of insect parasites of animals and humans. Insecticides are claimed to be a major factor behind the increase in the 20th-century's agricultural productivity. Nearly all insecticides have the potential to significantly alter ecosystems; many are toxic to humans and/or animals; some become concentrated as they spread along the food chain.

ಪೈರುಗಳಿಗೆ ಹಾನಿಕಾರಕವಾದ, ಜನಜೀವನಕ್ಕೆ ಉಪದ್ರವಕಾರಿಯಾದ ಕೀಟಗಳ ನಿರ್ಮೂಲನಕ್ಕೆ ಬಳಸುವ ರಾಸಾಯನಿಕಗಳು (ಇನ್‍ಸೆಕ್ಟಿಸೈಡ್ಸ್). ಈ ರಾಸಾಯನಿಕಗಳ ಪ್ರಭಾವಕ್ಕೆ ಒಳಗಾದ ಕೀಟಗಳ ಜೈವಿಕ ಕ್ರಿಯೆಗಳು ಏರುಪೇರಾಗಿ ಅವು ಸಾಯುವುವು.ಕೀಟನಾಶಕಗಳು ಸಾವಯವ ಅಥವಾ ನಿರವಯವ ವಸ್ತುಗಳಾಗಿರಬಹುದು. ಬಹುಪಾಲು ಕೀಟನಾಶಕಗಳು ಸಂಯೋಜಿತವಾದವು. ಅವುಗಳ ಕಾರ್ಯವಿಧಾನಕ್ಕೆ ಅನುಗುಣವಾಗಿ