The biopesticides are used as microbial biological pest control agents who applied in farming processes to replace chemical pesticides. Commonly used biopesticides are bacterial and fungal agents such as Trichoderma spp., Ampelomyces quisqualis (a control agent for grape powdery mildew), Bacillus subtilis (used to control plant pathogens).
Three major classes of biopesticides are:
1. Microbial pesticides: Microorganism (e.g., bacterium, fungus, virus or protozoan) are used as the active
bio-ingredients to control different kinds of pests. Strains of Bacillus thuringiensis produce different mix of proteins and specifically kills one or a few related species of insect larvae.
2. Plant-Incorporated-Protectants (PIPs) are pesticidal ingredients produced by genetically modified plants.
3. Biochemical pesticides are naturally occurring substances that control pests by non-toxic mechanisms e.g. insect sex pheromones.
Field use of biopesticidial products:
Bt products are used mainly in the control of the following pests: tobacco budworm (H. virescens), grass looper (M. latipes), diamondback moth (P. xylostella), maizeborer (S. frugiperda), cassava hornworm (Erinnyis ello L.; Lep., Sphingidae), potato leafminers (Liriomyza spp.), citrus leafminer (Phyllocnistis citrella Stainton; Lep., Gracillariidae), squash pickleworm (Diaphania spp.) and other lepidopteran defoliators in vegetables. Theacaricide product is also used for mite control in citrus, potato and plantain. Strains of Bt var. israelensis are used for control of mosquito disease vectors. During 1997, over 1000 tonnes of Bt were produced in Cuba, 24% by industrial fermentation and 76% via solid substrate culture. Larvicidal activity of neem oil (Azadirachta indica) is used against mosquitoes. Azadirachta indica (Meliaceae) and its derived products have shown a variety of insecticidal properties. Larvicidal efficacy of an emulsified concentrate of formulated neem oil (neem oil with polyoxyethylene ether, sorbitan dioleate and epichlorohydrin) is commonly used for agricultural and farming purposes.
Advantages of biopesticides:
1.When used as a component of Integrated Pest Management (IPM) programs, biopesticides can greatly decrease the use of conventional pesticides with high yield.
2.Biopesticides are usually inherently less toxic than conventional pesticides
3.Do not have left over of any harmful residues.
4.Have substantially nullified impact on non-target species.
5.They are cheaper than chemical pesticides.
6.They are effective than chemical pesticides.
Disadvantages of biopesticides:
1.They are high specific in mode of action for which they require an exact identification of the pest/pathogen.
2.Have slow and steady speed of action which may be unsuitable if a pest outbreak is an immediate threat to a crop.
3.Having often variable efficacy due to the influences of various biotic and abiotic factors (since biopesticides are usually living organisms, which bring about pest/pathogen control by multiplying within the target insect pest/pathogen).
4.Biopesticides are certain types of pesticides derived from such natural materials as animals, plants, bacteria, and certain minerals which might have eco-ethical issues too.
About Author / Additional Info:
Dr. Kirti Rani Sharma,
Assistant Professor (II),
Amity Institute of Biotechnology,
Amity University, sec-125, Gautam Buddha Nagar, Noida-201303 (UP), India.
Office Phone no: +91-120-4392946
Mobile No: +91-9990329492
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