ABSTRACT
Over the last decade, there has been an increasing consumer demand for food devoid of synthetic pesticides and a growing farmer concern about the immunity being developed by pests to some synthetic pesticides. Consequently, there has been a serious spurt of activity all over the world to gradually switch from synthetic to natural pesticides. Among common pesticides, DDT and BHC are considered carcinogenic and are already banned. Another synthetic pesticide, monochrotophos, has been placed on the watch list. In a recent report of the World Health Organization (WHO), the annual number of acute poisonings caused by synthetic pesticides has been estimated at 3 million, with 20,000 deaths every year. The number of insects resistant to these pesticides has increased significantly over the years. Some pests may soon be “beyond effective chemical control” as some experts believe. Several species of mites, nematodes, desert and migrating locusts, rice and maize borers, pulse beetle, rice weevil, citrus red mint, and white flies have developed resistance to synthetic pesticides, but have yet to develop resistance to a natural pesticide. Natural extracts from citronella, sassafras, aloe vera, chrysanthemums, and neem have been established for several years and are being marketed as alternative ecofriendly solutions to insect and pest controls. Pyrethrins isolated from chrysanthemums, piperonyl butoxide from sassafras, and azadirachtin from neem are some of the active ingredients used in the formulations of natural pesticides.
