April 6th 2010
Biopesticides can be considered as falling into three main categories1.
Microbial pesticides consist of a microorganism (e.g., a bacterium, fungus, virus or protozoan) as the active ingredient. Microbial pesticides can control many different kinds of pests, although each separate active ingredient is relatively specific for its target pest[s]. For example, there are fungi that control certain weeds, and other fungi that kill specific insects.
Plant-Incorporated-Protectants (PIPs) are pesticidal substances that plants produce from genetic material that has been added to the plant. For example, scientists can take the gene for the Bt pesticidal protein, and introduce the gene into the plant's own genetic material. Then the plant, instead of the Bt bacterium, manufactures the substance that destroys the pest.
Biochemical pesticides are naturally occurring substances that control pests by non-toxic mechanisms. Conventional pesticides, by contrast, are generally synthetic materials that directly kill or inactivate the pest. Biochemical pesticides include substances, such as insect sex pheromones, which interfere with mating, as well as various scented plant extracts that attract insect pests to traps. Because it is sometimes difficult to determine whether a substance meets the criteria for classification as a biochemical pesticide, EPA has established a special committee to make such decisions.
Biopesticides play an important role in providing pest management tools in areas where pesticide resistance, niche markets and environmental concerns limit the use of conventional chemical pesticide products. Examples are2:
Bacteria - Bacillus thuringiensis, B. sphaericus, Paenibacillus popilliae, Serratia entomophila
Viruses - nuclear polyhedrosis viruses, granulosis viruses, non-occluded baculoviruses
Fungi - Beauveria spp, Metarhizium, Entomophaga, Zoopthora, Paecilomyces fumosoroseus, Normuraea, Lecanicillium lecanii
Protozoa - Nosema, Thelohania, Vairimorpha
Entomopathogenic nematodes - Steinernema spp, Heterorhabditis spp
Others - Pheromones, parasitoids, predators, microbial by-products
Fungi - Colletotrichum gloeosporioides, Chondrostereum purpureum, Cylindrobasidium laeve
Bacteria - Xanthomonas campestris pv. Poannua
Plant Disease Control
Fungi - Ampelomyces quisqualis, Candida spp. , Clonostachys rosea f. catenulate, Coniothyrium minitans, Pseudozyma flocculosa, Trichoderma spp
Competitive and Soil Inoculants - Bacillus pumilus, B. subtilis, Pseudomonas spp, Streptomyces griseoviridis
Nematode Trapping Fungi - Myrothecium verrucaria, Paecilomyces lilacinus
Bacteria - Bacillus firmus, Pasteuria penetrans
Mollusc parasitic nematode - Phasmarhabditis hermaphrodita
Currently the most widely used biopesticide is Bacillus thuringiensis (Bt) which is an insecticide with unusual properties that make it useful for pest control in certain situations. Bt is a naturally occurring bacterium common in soils throughout the world. Several strains can infect and kill insects. Because of this property, Bt has been developed for insect control. The target insect species are determined by whether the particular Bt produces a protein that can bind to a larval gut receptor, thereby causing the insect larvae to starve. The insecticidal activity of Bt was first discovered in 1911. However, it was not commercially available until the 1950s. In recent years, there has been tremendous renewed interest in Bt. Several new products have been developed, largely because of the safety associated with Bt-based insecticides3. Since 1996 plants have been modified with short sequences of genes from Bt to express the crystal protein Bt makes. With this method, plants themselves can produce the proteins and protect themselves from insects without any external Bt and/or synthetic pesticide sprays. Bt GM crops are protected specifically against European corn borer, southwestern corn borer, tobacco budworm, cotton bollworm, pink bollworm and the Colorado potato beetle4.
Examples of biopesticides also include the use of fungi and bacteria to prevent damage to plants by pests and diseases5. UK researchers have demonstrated that biocontrol agents can also be applied to seeds during drum priming, a seed preparation method that is used commercially to improve germination. They demonstrated, for the first time, that during the drum priming process it is possible to apply mixtures of fungi (Clonostachys rosea IK726 or Trichoderma harzianum T22) and bacteria (Pseudomonas chlororaphis MA342 or P.fluorescens CHA0), to carrot and onion seeds6.
As with conventional chemical pesticides biopesticides also have to undergo a registration process. The US EPA wishes to facilitate the registration of biopesticides and promotes the use of safer pesticides, including biopesticides, as components of IPM programs. Since biopesticides tend to pose fewer risks than conventional pesticides, the EPA generally requires much less data to register a biopesticide than to register a conventional pesticide. In fact, new biopesticides are often registered in less than a year, compared with an average of more than 3 years for conventional pesticides1. The US EPA also publishes fact sheets on biopesticides which have undergone registration7.
In the EU biopesticides are regulated in the same way as conventional pesticides, requiring the same data sets. However, several draft documents have been produced to give guidance on the actual requirements when applied to biopesticides e.g. for plant extracts8, taxonomic level for micro-organisms9. The UK PSD has introduced a scheme to facilitate more alternative products to enter the market by giving early advice to potential registrants. This scheme covers products based on pheromone and other semiochemicals, microorganisms (e.g. bacterium, fungus, protozoa, virus and viroid), plant extracts and other novel products10. This scheme does not, however, cover GM plants.
The OECD has introduced the Pesticide Registration and Re-registration Project for Biological Pesticides (microbials, pheromones and semiochemicals and invertebrates such as insects and nematodes) to help governments work together to assess pesticide risks to man and the environment. By working together, governments can evaluate a biological pesticide's risks more quickly and thoroughly. This speeds up the process of approving safer new pesticides and stopping use of riskier ones. The project has focused on writing guidance for the submission and evaluation of biological pesticide test data11.
In the US the Environmental Protection Agency is responsible for the registration of “plant-incorporated protectants (PIP)” i.e. genetically modified crops. Identification of the new PIP character added to the plant generally follows guidance developed by the EPA, Canadian Food Inspection Agency (CFIA) and the USDA’s Animal and Plant Health Inspection Service ( APHIS). Guidelines have been produced by the EPA giving the requirements for registration12.
In the EU GM food and feed, i.e. crops producing pesticidal substances from genetic material that has been added to the plant, can only be authorised for placing on the market after a scientific assessment of any risks which they might present for human and animal health and, as the case may be, for the environment (according to Regulation (EC) 1829/2003)13. Detailed information on the requirements is given in a guidance document published by the European Food Safety Authority (EFSA)14,15.
Similar guidelines are available for Canada16 Australia17 – although here, if they are food organisms, after it is decided that they are safe in the form of crops to be released into the environment, they must also be approved by the Food Standards Australia New Zealand (FSANZ)18, Japan19,20 etc.
The OECD is currently looking at international regulation of GM crops, the main focus of the work is on international harmonization of regulatory oversight in modern biotechnology which will ensure that environmental health and safety aspects are properly evaluated, while avoiding non-tariff trade barriers to products of the technology21.
1. US Environmental Protection Agency – What are Biopesticides?
2. Society for Invertebrate Pathology – Microbial Control Division – Biopesticides
3. Colarado State University – Extension – Horticulture, Bacillus thuringiensis
4. University of California, San Diego - Bacillus thuringiensis
5. Potential of Microbial Control “Fungi”, Sebastian Kiewnick, Agroscope Changins-Wädenswil Research Station ACW, Switzerland, 19th September 2006
6. European Commission, DG Environment, News Alert Service – Chemical Pesticides on their Way Out?
7. US Environmental Protection Agency - Biopesticide Active Ingredient Fact Sheets
8. EU DG Health and Consumer Protection, Sanco/10472/2003 –rev.5, Concerning the Data Requirements for Active Substances of Plant Protection Products Made from Plants or Plant Extracts (2004)
9. EU DG Health and Consumer Protection, Sanco/10754/2005 –rev.5, Guideline developed within the Standing Committee on the Food Chain and Animal Health on the taxonomic level of micro-organisms to be included in Annex I to Directive 91/414/EEC (2005)
10. UK Pesticides Safety Directorate, Launch of New Biopesticides Scheme
11. OECD Environment Directorate, Biological Pesticide Registration
12. US Environmental Protection Agency, Introduction to Biotechnology Regulation for Pesticides
13. Official Journal of the European Union,L268/1, 18th October 2003, Regulation (EC) No 1829/2003 of the European Parliament and of the Council of 22 September 2003 on Genetically Modified Food and Feed,
14. Guidance Document of the Scientific Panel on Genetically Modified Organisms for the Risk Assessment of Genetically Modified Plants and Derived Food and Feed Use, The EFSA Journal (2006) 374, 1-115.
15. EFSA, EFSA Panel on Genetically Modified Organisms (GMO), Scientific Opinion on Statistical Considerations for the Safety Evaluation of GMOs
16. Food Directorate, Health Products and Food Branch, Health Canada - Guidelines for the Safety Assessment of Novel Foods (June 2006)
17. The Office of the Gene Technology Regulator, Commonwealth Department of Health and Aged Care, A Users Guide to the Gene Technology Act 2000 and Related Legislation
18. Food Standards Australia New Zealand, Genetically Modified (GM) Foods
19. Japan Ministry of the Environment, Japan Biosafety Clearing House, Domestic Law and Regulations
20. Ministry of Health, Labour and Welfare, Japan, Foods and Food Additives Produced by Recombinant DNA Techniques, Mandatory Requirement of the Safety Assessment Related Ordinances and announcements
21. OECD Environment Directorate, Harmonisation of Regulatory Oversight in Biotechnology
Last modified 6th April 2010
Date added: 2009-08-20 19:59:53
Last Updated 2010-05-10 04:38:11
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