Biopesticide
Encyclopedia
Biopesticides include "naturally occurring substances that control pests (biochemical pesticides), microorganisms that control pests (microbial pesticides), and pesticidal substances produced by plants containing added genetic material (plant-incorporated protectants) or PIPs."
Biopesticides are biochemical pesticide
s that are naturally occurring substances that control pests by nontoxic mechanisms. Conventional pesticides, by contrast, are generally synthetic materials that directly kill or inactivate the pests. For example, a plant in the presence of chitosan
will naturally induce systemic resistance (ISR) to allow the plant to defend itself against disease, pathogens and pests. Biopesticides are considered eco-friendly and easy to use. In the USA, the EPA regulates the registration and use of earth friendly biopesticides.
Biopesticides are key components of integrated pest management
(IPM) programmes, and are receiving much practical attention as a means to reduce the load of synthetic chemical products being used to control plant diseases.
Biopesticides have usually no known function in photosynthesis, growth or other basic aspects of plant physiology; however, their biological activity against insect pests, nematode
s, fungi and other organisms is well documented. Every plant species has developed a built-in unique chemical complex structure that protects it from pests
. The plant kingdom offers a diverse array of complex chemical structures and almost every imaginable biological activity. These biodegradable, economical and renewable alternatives are used especially under organic farming systems.
Biopesticides, key components of integrated pest management
(IPM) programmes, are receiving much practical attention as a means to reduce the load of synthetic chemical products being used to control plant diseases. In most cropping systems, biological pesticides should not necessarily be viewed as wholesale replacements for chemical control
of plant pests and diseases, but rather as a growing category of efficacious supplements that can be used as rotation agents to retard the onset of resistance to chemical pesticides and improve sustainability. In organic cropping systems, biopesticides can represent valuable tools that further supplement the rich collection of cultural practices that ensure against crop loss to diseases.
s, which include thousands of alkaloid
s, terpenoid
s, phenolic
s and minor secondary chemicals. Biopesticides are derived from such natural materials as animals, plants, bacteria, and certain minerals. For example, canola oil and baking soda have pesticidal applications and are considered biopesticides. At the end of 2001, there were approximately 195 registered biopesticide active ingredients and 780 products. Commonly these are bacteria
l, but there are also examples of control agents based on fungi, virus
es and nematode
s. Weed
s and rodent
s have also been controlled with microbial agents. An example from India is Bt cotton.
Various naturally-occurring materials, including fungal or plant extract
s, have been described as biopesticides. Products in this category include:
Bacillus thuringiensis
, a bacterial disease of Lepidoptera
, Coleoptera and Diptera
, is a well-known insecticide example. Because it has little effect on other organism
s, it is considered more environmentally friendly
than synthetic pesticides. The toxin from Bacillus thuringiensis
(Bt toxin) has been incorporated directly into plants through the use of genetic engineering
.
Other microbial control agents include products based on:
The Manual of Biocontrol Agents (2009) gives a review of the available biological insecticide (and other biology-based control) products.
agents that are applied in a manner similar to chemical pesticides. In order to implement these environmentally-friendly pest control agents effectively, it can be important to pay attention to the way they are formulated
and applied
.
Biopesticides for use against crop diseases have already established themselves on a variety of crops. For example, biopesticides already play an important role in controlling downy mildew diseases. Their benefits include: a 0-Day Pre-Harvest Interval (see: maximum residue limit
), the ability to use under moderate to severe disease pressure, and the ability to use as a tank mix or in a rotational program with other registered fungicides. Because some market studies estimate that as much as 20% of global fungicide sales are directed at downy mildew
diseases, the integration of biofungicides into grape production has substantial benefits in terms of extending the useful life of other fungicides, especially those in the reduced-risk category.
A major growth area for biopesticides is in the area of seed treatment
s and soil amendments. Fungicidal and biofungicidal seed treatments are used to control soil borne fungal pathogens that cause seed rots, damping-off, root rot
and seedling blights. They can also be used to control internal seed–borne fungal pathogens as well as fungal pathogens that are on the surface of the seed. Many biofungicidal products also show capacities to stimulate plant host defenses and other physiological processes that can make treated crops more resistant to a variety of biotic
and abiotic stresses.
Biopesticides are biochemical pesticide
Pesticide
Pesticides are substances or mixture of substances intended for preventing, destroying, repelling or mitigating any pest.A pesticide may be a chemical unicycle, biological agent , antimicrobial, disinfectant or device used against any pest...
s that are naturally occurring substances that control pests by nontoxic mechanisms. Conventional pesticides, by contrast, are generally synthetic materials that directly kill or inactivate the pests. For example, a plant in the presence of chitosan
Chitosan
Chitosan is a linear polysaccharide composed of randomly distributed β--linked D-glucosamine and N-acetyl-D-glucosamine...
will naturally induce systemic resistance (ISR) to allow the plant to defend itself against disease, pathogens and pests. Biopesticides are considered eco-friendly and easy to use. In the USA, the EPA regulates the registration and use of earth friendly biopesticides.
Biopesticides are key components of integrated pest management
Integrated Pest Management
Integrated pest management is an ecological approach to agricultural pest control that integrates pesticides/herbicides into a management system incorporating a range of practices for economic control of a pest...
(IPM) programmes, and are receiving much practical attention as a means to reduce the load of synthetic chemical products being used to control plant diseases.
Overview
Biopesticides fall into three major classes:- Microbial pesticides which consist of bacteria, entomopathogenic fungi or viruses (and sometimes includes the metabolites that bacteria or fungi produce). Entomopathogenic nematodes are also often classed as microbial pesticides, even though they are multi-cellular.
- Plant-incorporated protectants (PIPs) have genetic material from other species incorporated into their genetic material (i.e. GM crops).
- Biochemical pesticides are naturally occurring substances that control pests by nontoxic mechanisms.
Biopesticides have usually no known function in photosynthesis, growth or other basic aspects of plant physiology; however, their biological activity against insect pests, nematode
Nematode
The nematodes or roundworms are the most diverse phylum of pseudocoelomates, and one of the most diverse of all animals. Nematode species are very difficult to distinguish; over 28,000 have been described, of which over 16,000 are parasitic. It has been estimated that the total number of nematode...
s, fungi and other organisms is well documented. Every plant species has developed a built-in unique chemical complex structure that protects it from pests
Plant defense against herbivory
Plant defense against herbivory or host-plant resistance describes a range of adaptations evolved by plants which improve their survival and reproduction by reducing the impact of herbivores. Plants use several strategies to defend against damage caused by herbivores...
. The plant kingdom offers a diverse array of complex chemical structures and almost every imaginable biological activity. These biodegradable, economical and renewable alternatives are used especially under organic farming systems.
Biopesticides, key components of integrated pest management
Integrated Pest Management
Integrated pest management is an ecological approach to agricultural pest control that integrates pesticides/herbicides into a management system incorporating a range of practices for economic control of a pest...
(IPM) programmes, are receiving much practical attention as a means to reduce the load of synthetic chemical products being used to control plant diseases. In most cropping systems, biological pesticides should not necessarily be viewed as wholesale replacements for chemical control
Pesticide
Pesticides are substances or mixture of substances intended for preventing, destroying, repelling or mitigating any pest.A pesticide may be a chemical unicycle, biological agent , antimicrobial, disinfectant or device used against any pest...
of plant pests and diseases, but rather as a growing category of efficacious supplements that can be used as rotation agents to retard the onset of resistance to chemical pesticides and improve sustainability. In organic cropping systems, biopesticides can represent valuable tools that further supplement the rich collection of cultural practices that ensure against crop loss to diseases.
Examples
Biopesticides are natural plant products belonging to the so-called secondary metaboliteSecondary metabolite
Secondary metabolites are organic compounds that are not directly involved in the normal growth, development, or reproduction of an organism. Unlike primary metabolites, absence of secondary metabolities does not result in immediate death, but rather in long-term impairment of the organism's...
s, which include thousands of alkaloid
Alkaloid
Alkaloids are a group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms. This group also includes some related compounds with neutral and even weakly acidic properties. Also some synthetic compounds of similar structure are attributed to alkaloids...
s, terpenoid
Terpenoid
The terpenoids , sometimes called isoprenoids, are a large and diverse class of naturally occurring organic chemicals similar to terpenes, derived from five-carbon isoprene units assembled and modified in thousands of ways. Most are multicyclic structures that differ from one another not only in...
s, phenolic
Phenolic
Phenolic is an adjective and a substantive that may apply to :* Natural phenolics and polyphenols, two related classes of natural compounds found in plants* Phenol , a colorless crystalline solid and aromatic compound...
s and minor secondary chemicals. Biopesticides are derived from such natural materials as animals, plants, bacteria, and certain minerals. For example, canola oil and baking soda have pesticidal applications and are considered biopesticides. At the end of 2001, there were approximately 195 registered biopesticide active ingredients and 780 products. Commonly these are bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
l, but there are also examples of control agents based on fungi, virus
Virus
A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...
es and nematode
Nematode
The nematodes or roundworms are the most diverse phylum of pseudocoelomates, and one of the most diverse of all animals. Nematode species are very difficult to distinguish; over 28,000 have been described, of which over 16,000 are parasitic. It has been estimated that the total number of nematode...
s. Weed
Weed
A weed in a general sense is a plant that is considered by the user of the term to be a nuisance, and normally applied to unwanted plants in human-controlled settings, especially farm fields and gardens, but also lawns, parks, woods, and other areas. More specifically, the term is often used to...
s and rodent
Rodent
Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....
s have also been controlled with microbial agents. An example from India is Bt cotton.
Various naturally-occurring materials, including fungal or plant extract
Plant extract
Plant extract may refer to:* Herbalism and traditional medicine* Biopesticides...
s, have been described as biopesticides. Products in this category include:
- ChitinChitinChitin n is a long-chain polymer of a N-acetylglucosamine, a derivative of glucose, and is found in many places throughout the natural world...
- ChitosanChitosanChitosan is a linear polysaccharide composed of randomly distributed β--linked D-glucosamine and N-acetyl-D-glucosamine...
- SpinosadSpinosadSpinosad is a new chemical class of insecticides that are registered by the United States Environmental Protection Agency to control a variety of insects...
- Insect pheromones and other semiochemicalSemiochemicalA semiochemical is a generic term used for a chemical substance or mixture that carries a message. These chemicals acts as messengers within or between species...
s
Bacillus thuringiensis
Bacillus thuringiensis
Bacillus thuringiensis is a Gram-positive, soil-dwelling bacterium, commonly used as a biological pesticide; alternatively, the Cry toxin may be extracted and used as a pesticide. B...
, a bacterial disease of Lepidoptera
Lepidoptera
Lepidoptera is a large order of insects that includes moths and butterflies . It is one of the most widespread and widely recognizable insect orders in the world, encompassing moths and the three superfamilies of butterflies, skipper butterflies, and moth-butterflies...
, Coleoptera and Diptera
Diptera
Diptera , or true flies, is the order of insects possessing only a single pair of wings on the mesothorax; the metathorax bears a pair of drumstick like structures called the halteres, the remnants of the hind wings. It is a large order, containing an estimated 240,000 species, although under half...
, is a well-known insecticide example. Because it has little effect on other organism
Organism
In biology, an organism is any contiguous living system . In at least some form, all organisms are capable of response to stimuli, reproduction, growth and development, and maintenance of homoeostasis as a stable whole.An organism may either be unicellular or, as in the case of humans, comprise...
s, it is considered more environmentally friendly
Environmentally friendly
Environmentally friendly are terms used to refer to goods and services, laws, guidelines and policies claimed to inflict minimal or no harm on the environment....
than synthetic pesticides. The toxin from Bacillus thuringiensis
Bacillus thuringiensis
Bacillus thuringiensis is a Gram-positive, soil-dwelling bacterium, commonly used as a biological pesticide; alternatively, the Cry toxin may be extracted and used as a pesticide. B...
(Bt toxin) has been incorporated directly into plants through the use of genetic engineering
Genetic engineering
Genetic engineering, also called genetic modification, is the direct human manipulation of an organism's genome using modern DNA technology. It involves the introduction of foreign DNA or synthetic genes into the organism of interest...
.
Other microbial control agents include products based on:
- entomopathogenic fungi (e.g.Beauveria bassianaBeauveria bassianaBeauveria bassiana is a fungus that grows naturally in soils throughout the world and acts as a parasite on various arthropod species, causing white muscardine disease; it thus belongs to the entomopathogenic fungi. It is being used as a biological insecticide to control a number of pests such as...
, LecanicilliumLecanicilliumLecanicillium is a genus of fungi within the order Hypocreales and is described as anamorphic Cordycipitaceae; 21 species are currently described. These are entomopathogenic fungus species, that were previously widely known as Verticillium lecanii Viegas .The IndexFungorum records the following...
spp., MetarhiziumMetarhiziumMetarhizium is a genus of entomopathogenic fungi in the Clavicipitaceae family. With the advent of genetic profiling, it has now become possible to place these fungi in proper taxa. Most turn out to be the asexual forms of fungi in the phylum Ascomycota.- Species :Nine distinct species have now...
spp.), - plant disease control agents: include TrichodermaTrichodermaTrichoderma is a genus of fungi that is present in all soils, where they are the most prevalent culturable fungi. Many species in this genus can be characterized as opportunistic avirulent plant symbionts.-Species:...
spp. and Ampelomyces quisqualisAmpelomyces quisqualisAmpelomyces quisqualis is an anamorphic fungus that is a hyperparasite of powdery mildews. This parasitism reduces growth and may eventually kill the mildew, so investigations on biological control of powdery mildews have taken place for over 50 years, resulting in the development of products...
(a hyper-parasite of grape powdery mildewPowdery mildewPowdery mildew is a fungal disease that affects a wide range of plants. Powdery mildew diseases are caused by many different species of fungi in the order Erysiphales. It is one of the easier diseases to spot, as its symptoms are quite distinctive. Infected plants display white powdery spots on the...
); Bacillus subtilisBacillus subtilisBacillus subtilis, known also as the hay bacillus or grass bacillus, is a Gram-positive, catalase-positive bacterium commonly found in soil. A member of the genus Bacillus, B. subtilis is rod-shaped, and has the ability to form a tough, protective endospore, allowing the organism to tolerate...
is also used to control plant pathogens. - beneficial nematodeNematodeThe nematodes or roundworms are the most diverse phylum of pseudocoelomates, and one of the most diverse of all animals. Nematode species are very difficult to distinguish; over 28,000 have been described, of which over 16,000 are parasitic. It has been estimated that the total number of nematode...
s attacking insect (e.g. Steinernema feltiae) or slugSlugSlug is a common name that is normally applied to any gastropod mollusc that lacks a shell, has a very reduced shell, or has a small internal shell...
(e.g. Phasmarhabditis hermaphrodita) pests - entomopathogenic viruses (e.g.. Cydia pomonella granulovirusCydia pomonella granulosis virusCydia pomonella granulosis virus is a Baculovirus Granulovirus. It has a double-stranded DNA genome 123500 bp in length with 143 ORFs. The virus forms small bodies called granules containing a single viron. CpGV is a virus of invertebrates – specifically Cydia pomonella or the Codling moth...
).
The Manual of Biocontrol Agents (2009) gives a review of the available biological insecticide (and other biology-based control) products.
Applications
Biopesticides are typically microbial biological pest controlBiological pest control
Biological control of pests in agriculture is a method of controlling pests that relies on predation, parasitism, herbivory, or other natural mechanisms...
agents that are applied in a manner similar to chemical pesticides. In order to implement these environmentally-friendly pest control agents effectively, it can be important to pay attention to the way they are formulated
Pesticide formulation
The biological activity of a pesticide, be it chemical or biological in nature, is determined by its active ingredient . Pesticide products very rarely consist of pure technical material. The AI is usually formulated with other materials and this is the product as sold, but it may be further...
and applied
Pesticide application
Pesticide application refers to the practical way in which pesticides, are delivered to their biological targets...
.
Biopesticides for use against crop diseases have already established themselves on a variety of crops. For example, biopesticides already play an important role in controlling downy mildew diseases. Their benefits include: a 0-Day Pre-Harvest Interval (see: maximum residue limit
Maximum Residue Limit
Pesticide residues on crops are monitored with reference to Maximum Residue Limits and are based on analysis of quantity of a given AI remaining on food product samples...
), the ability to use under moderate to severe disease pressure, and the ability to use as a tank mix or in a rotational program with other registered fungicides. Because some market studies estimate that as much as 20% of global fungicide sales are directed at downy mildew
Downy mildew
Downy mildew refers to any of several types of oomycete microbes that are obligate parasites of plants. Downy mildews exclusively belong to Peronosporaceae. In commercial agriculture, they are a particular problem for growers of crucifers, grapes and vegetables that grow on vines...
diseases, the integration of biofungicides into grape production has substantial benefits in terms of extending the useful life of other fungicides, especially those in the reduced-risk category.
A major growth area for biopesticides is in the area of seed treatment
Seed treatment
In agriculture, a seed treatment or seed dressing is a chemical, typically antimicrobial or fungidal, with which seeds are treated prior to planting...
s and soil amendments. Fungicidal and biofungicidal seed treatments are used to control soil borne fungal pathogens that cause seed rots, damping-off, root rot
Root rot
Root rot is a condition found in both indoor and outdoor plants, although more common in indoor plants with poor drainage. As the name states, the roots of the plant rot. Usually, this is a result of overwatering. In houseplants, it is a very common problem, and is slightly less common in outdoor...
and seedling blights. They can also be used to control internal seed–borne fungal pathogens as well as fungal pathogens that are on the surface of the seed. Many biofungicidal products also show capacities to stimulate plant host defenses and other physiological processes that can make treated crops more resistant to a variety of biotic
Biotic
Biotic is a living component of a community; for example organisms, such as plants and animals.Biotic may also refer to:*Life, the condition of living organisms,*Biology, the study of life,*Biotic material, which is derived from living organisms,...
and abiotic stresses.
Advantages
- Do not leave harmful residues
- Substantially reduced impact on non-target species
- Can be cheaper than chemical pesticides when locally produced.
- Can be more effective than chemical pesticides in the long-term (as demonstrated, for example, by the LUBILOSALUBILOSALUBILOSA was the name of a research programme that aimed at developing a biological alternative to the chemical control of locusts. This name is an acronym of the French title of the programme: Lutte Biologique contre les Locustes et les Sauteriaux...
Programme)
Disadvantages
- High specificity, which will require an exact identification of the pest/pathogen and may require multiple pesticides to be used
- Often slow speed of action (thus making them unsuitable if a pest outbreak is an immediate threat to a crop)
- 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)
- Living organisms evolve and increase their resistance to biological, chemical, physical or any other form of control. If the target population is not exterminated or rendered incapable of reproduction, the surviving population can acquire a tolerance of whatever pressures are brought to bear, resulting in an evolutionary arms raceEvolutionary arms raceIn evolutionary biology, an evolutionary arms race is an evolutionary struggle between competing sets of co-evolving genes that develop adaptations and counter-adaptations against each other, resembling an arms race, which are also examples of positive feedback...
.
See also
- BioherbicideBioherbicideA bioherbicide is a biologically based control agent for weeds. Among the three major types of pesticides herbicides are used to control weeds, or undesirable plants. A bioherbicide is a biologically based control agent for weeds. Among the three major types of pesticides (agricultural...
- Biological pest controlBiological pest controlBiological control of pests in agriculture is a method of controlling pests that relies on predation, parasitism, herbivory, or other natural mechanisms...
- Integrated Pest ManagementIntegrated Pest ManagementIntegrated pest management is an ecological approach to agricultural pest control that integrates pesticides/herbicides into a management system incorporating a range of practices for economic control of a pest...
- LUBILOSALUBILOSALUBILOSA was the name of a research programme that aimed at developing a biological alternative to the chemical control of locusts. This name is an acronym of the French title of the programme: Lutte Biologique contre les Locustes et les Sauteriaux...
- Plant defense against herbivoryPlant defense against herbivoryPlant defense against herbivory or host-plant resistance describes a range of adaptations evolved by plants which improve their survival and reproduction by reducing the impact of herbivores. Plants use several strategies to defend against damage caused by herbivores...
External links
- Registered Biopesticides 04/29/02 United States Environmental Protection Agency. Updated 29 March 2002. Retrieved 25 November 2011.
- Biopesticide Industry Alliance (BPIA)
- International Biocontrol Manufacturers' Association (IBMA)