Biopesticide Information > Section 1: Biopesticide Definitions and Registration Process
The Environmental Protection Agency defines biopesticides as certain types of pesticides derived from natural materials such as animals, plants, bacteria, and certain minerals. Canola oil, garlic, mint oil and baking soda, for example, have pesticidal applications and are considered biopesticides.
Biopesticides are considered an effective pest control option for organic crop production. However, they increasingly are being recommended and used as components of Integrated Pest Management programs in the production of high-value specialty crops such as fruit, nut, vegetable, vine, ornamental, and turf.
At the end of 2008, there were approximately 245 registered biopesticide active ingredients used in products as varied as deer repellent and skin-applied insect repellents, as well as pest control products for commercial agriculture. As more natural pesticidal materials are identified and adapted for use, the number of registered products will continue to grow. Currently, the EPA recognizes three major classes of biopesticides:
1. Microbial pesticides consist of a microorganism (e.g., a bacterium, fungus, virus or protozoan) as the active ingredient used to control pests. The microorganism may occur naturally, be dead or alive, or be genetically engineered. 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.
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| Streptomyces lydicus Biofungicide | Trichoderma, Gliocladium for root diseases |
The most widely used microbial pesticides are subspecies and strains of Bt, Bacillus thuringiensis. Bt was first registered by the EPA in 1961. Each strain of this bacterium produces a different mix of proteins, and specifically kills one or a few related species of insect larvae. While some Bt strains control moth larvae found on plants, other strains are specific for larvae of flies and mosquitoes.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.
2. Biochemical pesticides are naturally occurring substances, such as plant extracts, fatty acids or pheromones, that control pests using a nontoxic mode of action to the pest. Conventional pesticides, by contrast, are generally synthetic materials that directly kill or inactivate the pest, most frequently by attacking the nervous system. Biochemical pesticides, while nontoxic, can be lethal such as clays that suffocate insects, anti-feeding compounds that cause starvation, or vinegar that kills plants. Other biochemical pesticides include substances such as insect sex pheromones that disrupt mating, repellents that protect plants from deer or insect pests, and various scented plant extracts that attract insect pests to traps. The EPA has established a special committee to evaluate products and to determine whether a substance meets the criteria for classification as a biochemical pesticide.
3. Plant-Incorporated-Protectants (PIPs) are pesticidal substances that plants produce from genetic material that has been added to the plant, such as corn and cotton. Scientists have taken the gene for the Bt pesticidal protein, and introduced the gene into the plant's own genetic material. The plant, instead of the Bt bacterium, manufactures the substance that destroys the pest. The protein and its genetic material, but not the plant itself, are regulated by EPA.
The success of PIPs in wide-scale commercial row-crop production cannot be ignored. According to the USDA-ARS, tobacco budworm ( Heliothis virescens ) and bollworm ( Helicoverpa zea ) are two of the most destructive pests in cotton and other crops, with costs of control, production, and lost yield of up to $300 million per year in the United States alone. In the late 1980s industry began to develop crops with built-in pest control from Bacillus thuringiensis ( Bt ) genes, which produce proteins toxic to several insects, including tobacco budworm and bollworm.
Cotton was one of the first crops to benefit from biotechnology-supplied pest protection, and Bt cotton is now one of the most widely used transgenic crops. It is currently grown throughout the United States, China, India, and Australia. More than 2 million acres of Bt cotton are grown in the United States alone. Other crops, including corn, potatoes, and soybeans, also now contain Bt genes.
The use of PIPs or genetically modified crops is generally considered to be based on planting and crop management decisions. For this reason, only the use of microbial and biochemical pesticides in effective pest management programs are discussed in this course.
Before a conventional pesticide can be marketed and used in the United States , the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) requires that EPA evaluate the proposed pesticide to assure that its use will not pose "unreasonable risks of harm to human health and the environment." This regulation involves an extensive review of health and safety information. To that end, the EPA may require more than 140 different studies on a chemical's toxicology, crop residues and environmental effects. The EPA also sets tolerances (maximum pesticide residue levels) for the amount of the pesticide that can legally remain in or on foods.
Typically biopesticides receive exemptions from tolerance because they are biodegradable or microbials and the establishment of residue levels is not appropriate.
Biopesticides are regulated by the same laws and regulations as chemical pesticides by the Biopesticide Pollution and Prevention Division at the EPA. However, because biopesticides tend to pose fewer risks than conventional pesticides, EPA generally requires less data to register a biopesticide than to register a conventional pesticide. Accordingly, new biopesticides are registered in less than the average of 3 years it takes to register conventional pesticides. The time for biopesticide approval is 12 months for ornamentals and turf (nonfood crops) and 18 months for food crops, as governed by the Pesticide Registration Improvement Act (PRIA).
The EPA has implemented a tiered approach to biochemical pesticide data requirements that reduces the amount of testing, and saves money, time, and the number of animal tests. The EPA may waive certain data requirements if the original product chemistry or substance is food grade. If initial toxicity tests are negative at the maximum dose, no further testing is required, especially where the substance is well known. Also, public literature is frequently used to support a biochemical compound. According to EPA, most pheromone compounds have been exempted from testing through a deregulation process
Microbial pesticides have slightly different EPA protocol. These products are predominately bacteria, but also include fungi and viruses, which can directly kill an insect pest or out-compete a naturally occurring pest species. Each strain of these pesticides is registered as a separate active ingredient.
EPA requires the following for microbial pesticides:
- product charter and keeping of specimens in a recognized culture collection
- track pathogenicity rather than toxicity (how long does it take for the microbe to clear from a test animal), and
- more extensive non-target testing than for chemical pesticides because these are living organisms capable of reproducing in the field. For example, 30-day feeding studies to assess pathogenicity against ladybeetles, lacewings and bees are required.
Though the time line is reduced, field testing for biopesticides to be registered for use on high-value specialty crops such as fruit, vegetables, nursery plants and ornamentals is disproportionately expensive for small biopesticide manufacturers. Additionally, the return on investment for the agrichemical industry is limited when compared to that of conventional pesticide development and use.
According to the U.S. Agriculture Census, these high-value crops account for more than $43 billion in annual production. Minor food crops are raised on 12 million acres of farmland and account for approximately 40 percent of all U.S. crop sales. Domestic specialty crop production could not be successful without access to many of the same pesticides used by large acreage crop producers. However, the lack of financial incentives to the agrichemical industry limits the registration of minor crop pesticide applications. Recognizing this problem, the USDA and state agricultural experiment stations organized the Interregional Research Project Number 4 (IR-4) to help minor acreage, specialty crop producers obtain EPA tolerances and new registered uses for pest control products. The IR-4 Project is publicly funded and works closely with growers and commodity groups, state university extension researchers, USDA scientists, the agrichemical industry, and EPA. Examples of IR-4 research projects include the use of pheromones (mating disruption) to help control codling moth in Michigan apples; using fungus and bacterium-based products to control Sclerotinia (lettuce drop) in Arizona lettuce; and using phosphite and diphosphite products to control pythium in a variety of greenhouse crops.
One of the goals of the IR-4 Project is to ensure that safe and efficient alternative pest control products such as biopesticides are available to producers by facilitating the registration of biopesticides. In 2008, t he IR-4 Biopesticide Program funded 29 research projects to provide data to support expansions on a number of biopesticide registrations. IR-4's efforts supported 18 new or modified products which could provide 128 new biopesticide uses. The IR-4 Project also maintains a database of biopesticides available to combat specific pests and diseases on numerous crops. The database, a joint project between the EPA and biopesticides manufacturers, helps link these small biopesticide companies and their products with growers and researchers. The database, housed at Rutgers University, can be accessed at http://www.ir4.rutgers.edu/index.html.
The EPA recognizes that biopesticides are generally lower risk than conventional pesticides and encourages the increased development and use of biopesticides. The use of safer pesticides, including biopesticides, is encouraged as a component of integrated pest management programs. Effective pest management tools such as IPM programs enable producers to manage for pesticide resistance while maintaining a safe and dependable food supply.
The use of biopesticides, according to industry experts, can provide numerous benefits in crop production and turf management.