Chemical pesticides when used judiciously provided a valuable tool in pest management. However use of sub lethal doses rendered pest tolerant to pesticides, and improper pesticide resulted in the outbreak of minor pest as major ones. There are various methods by which pest population can be reduced. These include physicals, cultural, chemical, biological and integrated pest control.Pesticides are chemical compounds or mixture of chemicals, specifically designed and manufactured to prevent, destroy, repell, attract, sterilise, stupefy or mitigate any undesired life declared to be the pest. Pesticides may be classified as insecticides, herbicides, rodenticides, fumigants, fungicides, mulluscicides, ascaricides and nematocides. Their toxicity varies from low to high.Neem has been recognized as a natural pesticide, as long back as “the village pharmacy” in India and Africa. Neem pesticide seems remarkably safer to predatory spiders, wasps, ladybugs, and honeybees. Neems natural pesticides are more or less completely non-toxic to mammals. Neem has more than two dozen pesticide compounds, out of which-Azadrachtin, Salenin, Meliantrol Nimbin and Ninbolin are of significance to establish it as a vital natural pesticide.Bacillus thuringiensis is a soil bacteria which posses natural insecticidal proteins. The primary insecticidal activity of B. Thurengiensis resides in a parasporal glycoprotein crystal that is synthesized within the organism during its speculation cycle. B. thurengiensis subspecies Kurstaki, Berliner, alesti and tolworthi all produce crystals that are similar structurally, bio-chemically, immunologically and functionally.Mode of action of insecticide occur indifferent ways. Some of them are physical poisons, some are protoplasmic poisons, a few are respiratory poisons, but most of them are nerve poisons. The insecticides upset the normal behaiour and action of the target organisms. Many herbicide attack chloroplast and stop photosynthesis. They inhibit photosynthetic electron transport and influence and/or breakdown of the accompanying pigments.Our dependence of pesticides have increased upto the extent that if modern agriculture will attempt to operate without them, crop production will decline, food prices will soar far higher and food shortage will become even more severe. However, pesticides have created two major serious problems: Firstly, many of them have persisted and accumulated in the environment and contaminated the non-target organisms and, secondly, many of them have directly or indirectly affected human health. Thus, the use of pesticides have a poor reputation, and that is why, they have been reckoned as “double edged swards” of “ecological narcotics” much because of their negative potentials.Biological pest control involves eradication or suppression of pests by encouragement, artificial introduction, or increase of natural enemies such as parasites, predators, and disease causing organisms. It is not only harmless, more effective , self perpetuating, ecologically sound, economical and free from environmental pollution, toxic health hazards and other undesirable side effects. Micro-organisms degrade pesticides residues to less toxic compounds. Pesticide degradation by enzymes is further attractive. Immobilised enzymes are best for pesticide degradation because the transport of pesticides into microbial cell is difficult and enzymes can be lost in one attempt. Pesticides degradation characters have been located on plasmids, which provide clues for genetic manipulation for development of new microbial strains capable of efficiently degrading pesticides.Integrated pest management is a dynamic concept which utilizes all suitable techniques in a compatible manner, to maintain pest population at levels below those causing economic injury. It involves use of insecticides at the weakest and most vulnerable stage of a pest; prefer selective pesticide over broad spectrum ones, application of pesticide timed to favour natural enemies, selectivity and dose reduction by appropriate treatment, localized use of systemic pesticides, addition of a synergist. Integrated pest management is ecologically sound management strategy based on natural agents, selective biocides and other low cost and less harmful inputs.This book contains twenty chapters, followed by bibliography and subject index. Inclusion of tables and figures present an authoritative explanation and discussion related to pesticide pollution, at a level suitable medicine, administration and planning. For the increasing number of teachers and students involved in degree and diploma courses in environmental science.ContentsIntroductionPesticidesNatural pesticides from NeemThuringiensis toxin as a natural pesticideMode of herbicide actionCurrent states of pesticidesPesticide pollutionPesticidal toxicity in the ecosystem Pesticide contamination of human beingPesticide contamination of foodBioassay of insecticidesBio-efficacy of pesticides