Green pesticides (also called ecological pesticides) are pesticides which are believed to be environmentally friendly and thus cause less harm to the ecosystem and animal health. In agroecology, pesticides are evaluated for minimal adverse environmental effects. Biocides include germicides, antibiotics, antibacterials, antivirals, antifungals, antiprotozoals and antiparasites. Pesticides typically come in the form of sprays and dusts. Many ecological pesticides are biological pesticides, but others are minerals or chemical compounds.

Although the pesticides and particularly insecticides used in organic farming are generally safer than synthetic pesticides, they are not necessarily safer and more environmentally friendly than synthetic pesticides. The main criterion for organic pesticides is that they are naturally-derived, and some naturally-derived substances have been controversial. Controversial natural pesticides include rotenone, copper, nicotine sulfate, and pyrethrums However, restrictions on natural pesticides have tightened and as of 2005 rotenone, a dangerous natural pesticide, was not allowed for US organic farmers, and rotenone was not allowed under the California Organic Foods Act of 1990. Phytoalexin elicitor glucohexatose has been called a green pesticide, as has a new class of insecticides called spinosad which shows "remarkable selectivity" in destroying harmful pests and leaving beneficial insects alive.

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For more information (background, pictures, experiments and references): Green Pesticide