Prospects of Botanical Biopesticides in Insect Pest Management
Conventional insecticides possess inherent toxicities that endanger the health of the farm operators, consumers and the environment. Negative effects on human health led to a resurgence in interest in botanical insecticides because of their minimal costs and ecological side effects. Botanicals are encouraging over broad-spectrum conventional pesticides. They affect only target pest and closely related organisms, effective in very small quantities, decompose quickly and provide the residue free food and a safe environment to live. When incorporated in integrated pest management programs, botanical pesticides can greatly decrease the use of conventional pesticides or used in rotation or in combination with other insecticides, potentially lessening the overall quantities applied and possibly mitigating or delaying the development of resistance in pest populations. Although the use of rotenone and nicotine appears to be waning, pyrethrum and neem are well established commercially, pesticides based on plant essential oils have recently entered the marketplace. Plant- based insecticides induce not only acute toxicity to pests but also deterrence and/or repellence which may contribute to overall efficacy against some pests that cause great economic losses at the pre- as well postharvest stages of the crop production and transmit diseases to animals and humans. This review provides information about pyrethrum, rotenone, nicotine and other traditional botanicals, as well as the newer botanicals, neem and essential oils. I discussed their effectiveness, uses, safety, commercialization and future trends of plant- based insecticides. Botanical insecticides are desirable alternatives to synthetic chemical insecticides for controlling pests. They are best suited for use in organic food production in industrialized countries but can play a much greater role in developing countries as a new class of ecofriendly products for controlling pests.