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A biopesticide is a biological substance or organism that damages, kills, or repels organisms seen as pests. Biological pest management intervention involves predatory, parasitic, or chemical relationships.
They are obtained from organisms including plants, bacteria and other microbes, fungi, nematodes, etc. [1] [ page needed ] [2] They are components of integrated pest management (IPM) programmes, and have received much practical attention as substitutes to synthetic chemical plant protection products (PPPs).
The U.S. Environmental Protection Agency states that biopesticides "are certain types of pesticides derived from such natural materials as animals, plants, bacteria, and certain minerals, and currently, there are 299 registered biopesticide active ingredients and 1401 active biopesticide product registrations." [3] The EPA also states that 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". [4]
The European Environmental Agency defines a biopesticide as “a pesticide made from biological sources, that is from toxins which occur naturally. - naturally occurring biological agents used to kill pests by causing specific biological effects rather than by inducing chemical poisoning.” Furthermore, the EEA defines a biopesticide as a pesticide in which “the active ingredient is a virus, fungus, or bacteria, or a natural product derived from a plant source. A biopesticide's mechanism of action is based on specific biological effects and not on chemical poisons.” [5]
Biopesticides usually have no known function in photosynthesis, growth or other basic aspects of plant physiology. Many chemical compounds produced by plants protect them from pests; they are called antifeedants. These materials are biodegradable and renewable, which can be economical for practical use. Organic farming systems embraces this approach to pest control. [6]
Biopesticides can be classified thusly:
RNA interference is under study for use in spray-on insecticides (RNAi insecticides) by companies including Syngenta and Bayer. Such sprays do not modify the genome of the target plant. The RNA can be modified to maintain its effectiveness as target species evolve to tolerate the original. RNA is a relatively fragile molecule that generally degrades within days or weeks of application. Monsanto estimated costs to be on the order of $5/acre. [12]
RNAi has been used to target weeds that tolerate Roundup. RNAi can be mixed with a silicone surfactant that lets the RNA molecules enter air-exchange holes in the plant's surface. This disrupted the gene for tolerance long enough to let the herbicide work. This strategy would allow the continued use of glyphosate-based herbicides. [12]
They can be made with enough precision to target specific insect species. Monsanto is developing an RNA spray to kill Colorado potato beetles. One challenge is to make it stay on the plant for a week, even if it's raining. The potato beetle has become resistant to more than 60 conventional insecticides. [12]
Monsanto lobbied the U.S. EPA to exempt RNAi pesticide products from any specific regulations (beyond those that apply to all pesticides) and be exempted from rodent toxicity, allergenicity and residual environmental testing. In 2014 an EPA advisory group found little evidence of a risk to people from eating RNA. [12]
However, in 2012, the Australian Safe Food Foundation claimed that the RNA trigger designed to change the starch content of wheat might interfere with the gene for a human liver enzyme. Supporters countered that RNA does not appear to survive human saliva or stomach acids. The US National Honey Bee Advisory Board told EPA that using RNAi would put natural systems at "the epitome of risk". The beekeepers cautioned that pollinators could be hurt by unintended effects and that the genomes of many insects are still undetermined. Other unassessed risks include ecological (given the need for sustained presence for herbicides) and possible RNA drift across species boundaries. [12]
Monsanto invested in multiple companies for their RNA expertise, including Beeologics (for RNA that kills a parasitic mite that infests hives and for manufacturing technology) and Preceres (nanoparticle lipidoid coatings) and licensed technology from Alnylam and Tekmira. In 2012 Syngenta acquired Devgen, a European RNA partner. Startup Forest Innovations is investigating RNAi as a solution to citrus greening disease that in 2014 caused 22 percent of oranges in Florida to fall off the trees. [12]
Mycopesticides include fungi and fungi cell components. Propagules such as conidia, blastospores, chlamydospores, oospores, and zygospores have been evaluated, along with hydrolytic enzyme mixtures. The role of hydrolytic enzymes especially chitinases in the killing process, and the possible use of chitin synthesis inhibitors are the prime research areas. [13]
The encapsulation of some biological compounds in nanoparticulate systems has been shown to improve their effectiveness against pests, reduce their toxicity toward people and the environment, and lessen the losses caused by physical deterioration (such as volatilization and leaching). [14] [15] [16] Thus, nanotechnology may aid in the creation of less toxic biopesticides with acceptable safety profiles, greater active agent stability, improved efficacy against the intended pests, and higher end-user acceptance. [15] [17] [18] Neem (Azadirachtaindica) oil can be effectively protected from quick degradation by the use of nanoparticles, providing a more sustained action on the intended pests. The biodegradable polymers utilised in this type of formulation enable continuous administration of the active ingredient with no damage to the environment. Because there is currently a lack of extensive understanding regarding risk assessment factors and the subsequent toxicity of nanoparticles towards components of agroecosystems after their release into the environment, future research must focus on ways to avoid the risks associated with the use of nanoparticles. [19]
Bacillus thuringiensis is a bacterium capable of causing disease of Lepidoptera, Coleoptera and Diptera. The toxin from B. thuringiensis (Bt toxin) has been incorporated directly into plants via genetic engineering. Bt toxin manufacturers claim it has little effect on other organisms, and is more environmentally friendly than synthetic pesticides.
Other microbial control agents include products based on:
Various animal, fungal, and plant organisms and extracts have been used as biopesticides. Products in this category include:
Microbial agents, effective control requires appropriate formulation [23] and application. [24] [25]
Biopesticides have established themselves on a variety of crops for use against crop disease. For example, biopesticides help control downy mildew diseases. Their benefits include: a 0-day pre-harvest interval (see: maximum residue limit), success under moderate to severe disease pressure, and the ability to use as a tank mix or in a rotational program with other 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 by extending the useful life of other fungicides, especially those in the reduced-risk category.[ citation needed ]
A major growth area for biopesticides is in the area of seed treatments and soil amendments. Fungicidal and biofungicidal seed treatments are used to control soil-borne fungal pathogens that cause seed rot, damping-off, root rot and seedling blights. They can also be used to control internal seed-borne fungal pathogens as well as fungal pathogens on the seed surface. Many biofungicidal products show capacities to stimulate plant host defense and other physiological processes that can make treated crops more resistant to stresses.[ citation needed ]
The market for agricultural biologicals was forecast to reach $19.5 billion by 2031. [27]
Bacillus thuringiensis is a gram-positive, soil-dwelling bacterium, the most commonly used biological pesticide worldwide. B. thuringiensis also occurs naturally in the gut of caterpillars of various types of moths and butterflies, as well on leaf surfaces, aquatic environments, animal feces, insect-rich environments, and flour mills and grain-storage facilities. It has also been observed to parasitize moths such as Cadra calidella—in laboratory experiments working with C. calidella, many of the moths were diseased due to this parasite.
Pesticides are substances that are used to control pests. They include herbicides, insecticides, nematicides, fungicides, and many others. The most common of these are herbicides, which account for approximately 50% of all pesticide use globally. Most pesticides are used as plant protection products, which in general protect plants from weeds, fungi, or insects. In general, a pesticide is a chemical or biological agent that deters, incapacitates, kills, or otherwise discourages pests. Target pests can include insects, plant pathogens, weeds, molluscs, birds, mammals, fish, nematodes (roundworms), and microbes that destroy property, cause nuisance, or spread disease, or are disease vectors. Along with these benefits, pesticides also have drawbacks, such as potential toxicity to humans and other species.
Insecticides are pesticides used to kill insects. They include ovicides and larvicides used against insect eggs and larvae, respectively. Insecticides are used in agriculture, medicine, industry and by consumers. Insecticides are claimed to be a major factor behind the increase in the 20th-century's agricultural productivity. Nearly all insecticides have the potential to significantly alter ecosystems; many are toxic to humans and/or animals; some become concentrated as they spread along the food chain.
Biological control or biocontrol is a method of controlling pests, whether pest animals such as insects and mites, weeds, or pathogens affecting animals or plants by using other organisms. It relies on predation, parasitism, herbivory, or other natural mechanisms, but typically also involves an active human management role. It can be an important component of integrated pest management (IPM) programs.
Pesticide resistance describes the decreased susceptibility of a pest population to a pesticide that was previously effective at controlling the pest. Pest species evolve pesticide resistance via natural selection: the most resistant specimens survive and pass on their acquired heritable changes traits to their offspring. If a pest has resistance then that will reduce the pesticide's efficacy – efficacy and resistance are inversely related.
A biocide is defined in the European legislation as a chemical substance or microorganism intended to destroy, deter, render harmless, or exert a controlling effect on any harmful organism. The US Environmental Protection Agency (EPA) uses a slightly different definition for biocides as "a diverse group of poisonous substances including preservatives, insecticides, disinfectants, and pesticides used for the control of organisms that are harmful to human or animal health or that cause damage to natural or manufactured products". When compared, the two definitions roughly imply the same, although the US EPA definition includes plant protection products and some veterinary medicines.
Integrated pest management (IPM), also known as integrated pest control (IPC) is a broad-based approach that integrates both chemical and non-chemical practices for economic control of pests. IPM aims to suppress pest populations below the economic injury level (EIL). The UN's Food and Agriculture Organization defines IPM as "the careful consideration of all available pest control techniques and subsequent integration of appropriate measures that discourage the development of pest populations and keep pesticides and other interventions to levels that are economically justified and reduce or minimize risks to human health and the environment. IPM emphasizes the growth of a healthy crop with the least possible disruption to agro-ecosystems and encourages natural pest control mechanisms." Entomologists and ecologists have urged the adoption of IPM pest control since the 1970s. IPM allows for safer pest control.
Fungicides are pesticides used to kill parasitic fungi or their spores. Fungi can cause serious damage in agriculture, resulting in critical losses of yield, quality, and profit. Fungicides are used both in agriculture and to fight fungal infections in animals. Fungicides are also used to control oomycetes, which are not taxonomically/genetically fungi, although sharing similar methods of infecting plants. Fungicides can either be contact, translaminar or systemic. Contact fungicides are not taken up into the plant tissue and protect only the plant where the spray is deposited. Translaminar fungicides redistribute the fungicide from the upper, sprayed leaf surface to the lower, unsprayed surface. Systemic fungicides are taken up and redistributed through the xylem vessels. Few fungicides move to all parts of a plant. Some are locally systemic, and some move upward. Most fungicides that can be bought retail are sold in liquid form, the active ingredient being present at 0.08% in weaker concentrates, and as high as 0.5% for more potent fungicides. Fungicides in powdered form are usually around 90% sulfur.
Pest control is the regulation or management of a species defined as a pest; such as any animal, plant or fungus that impacts adversely on human activities or environment. The human response depends on the importance of the damage done and will range from tolerance, through deterrence and management, to attempts to completely eradicate the pest. Pest control measures may be performed as part of an integrated pest management strategy.
The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) is a United States federal law that set up the basic U.S. system of pesticide regulation to protect applicators, consumers, and the environment. It is administered and regulated by the United States Environmental Protection Agency (EPA) and the appropriate environmental agencies of the respective states. FIFRA has undergone several important amendments since its inception. A significant revision in 1972 by the Federal Environmental Pesticide Control Act (FEPCA) and several others have expanded EPA's present authority to oversee the sales and use of pesticides with emphasis on the preservation of human health and protection of the environment by "(1) strengthening the registration process by shifting the burden of proof to the chemical manufacturer, (2) enforcing compliance against banned and unregistered products, and (3) promulgating the regulatory framework missing from the original law".
An entomopathogenic fungus is a fungus that can kill or seriously disable insects.
Acibenzolar-S-methyl is the ISO common name for an organic compound that is used as a fungicide. Unusually, it is not directly toxic to fungi but works by inducing systemic acquired resistance, the natural defence system of plants.
Oidium mangiferae is a plant pathogen that infects mango trees causing powdery mildew. Powdery mildew of mango is an Ascomycete pathogen of the Erysiphales family that was initially described by Berthet in 1914, using samples collected from Brazil. O. mangiferae is found in all areas where mangoes have been raised long term, but is particularly widespread in India where both the host and the pathogen are native. Currently no teleomorph stage has been identified, but due to certain morphological characteristics it has been suggested that O. mangiferae belongs in the Erysiphe polygony group. Mango is the only known host for this pathogen, though O. mangiferae appears to be identical to fungi responsible for powdery mildew diseases on various other plant species, particularly oak, though some differences may be observed. In particular, the number of cells in conidiophores varies from 2 on mango to 3-5 on oak. O. mangiferae has been known to infect oak leaves in the laboratory, however due to the lack of a known teleomorph stage O. mangiferae is still considered to only be a pathogen of mango. Recent analysis of its ribosomal DNA suggests it is conspecific with Erysiphe alphitoides, the causative agent of powdery mildew in European oaks.
Pesticide application refers to the practical way in which pesticides are delivered to their biological targets. Public concern about the use of pesticides has highlighted the need to make this process as efficient as possible, in order to minimise their release into the environment and human exposure. The practice of pest management by the rational application of pesticides is supremely multi-disciplinary, combining many aspects of biology and chemistry with: agronomy, engineering, meteorology, socio-economics and public health, together with newer disciplines such as biotechnology and information science.
The environmental effects of pesticides describe the broad series of consequences of using pesticides. The unintended consequences of pesticides is one of the main drivers of the negative impact of modern industrial agriculture on the environment. Pesticides, because they are toxic chemicals meant to kill pest species, can affect non-target species, such as plants, animals and humans. Over 98% of sprayed insecticides and 95% of herbicides reach a destination other than their target species, because they are sprayed or spread across entire agricultural fields. Other agrochemicals, such as fertilizers, can also have negative effects on the environment.
This is an index of articles relating to pesticides.
Soil microbiology is the study of microorganisms in soil, their functions, and how they affect soil properties. It is believed that between two and four billion years ago, the first ancient bacteria and microorganisms came about on Earth's oceans. These bacteria could fix nitrogen, in time multiplied, and as a result released oxygen into the atmosphere. This led to more advanced microorganisms, which are important because they affect soil structure and fertility. Soil microorganisms can be classified as bacteria, actinomycetes, fungi, algae and protozoa. Each of these groups has characteristics that define them and their functions in soil.
Early twenty-first century pesticide research has focused on developing molecules that combine low use rates and that are more selective, safer, resistance-breaking and cost-effective. Obstacles include increasing pesticide resistance and an increasingly stringent regulatory environment.
Industrial microbiology is a branch of biotechnology that applies microbial sciences to create industrial products in mass quantities, often using microbial cell factories. There are multiple ways to manipulate a microorganism in order to increase maximum product yields. Introduction of mutations into an organism may be accomplished by introducing them to mutagens. Another way to increase production is by gene amplification, this is done by the use of plasmids, and vectors. The plasmids and/ or vectors are used to incorporate multiple copies of a specific gene that would allow more enzymes to be produced that eventually cause more product yield. The manipulation of organisms in order to yield a specific product has many applications to the real world like the production of some antibiotics, vitamins, enzymes, amino acids, solvents, alcohol and daily products. Microorganisms play a big role in the industry, with multiple ways to be used. Medicinally, microbes can be used for creating antibiotics in order to treat infection. Microbes can also be used for the food industry as well. Microbes are very useful in creating some of the mass produced products that are consumed by people. The chemical industry also uses microorganisms in order to synthesize amino acids and organic solvents. Microbes can also be used in an agricultural application for use as a biopesticide instead of using dangerous chemicals and or inoculants to help plant proliferation.
Tariq Butt is a British entomologist. He is a Professor of Biosciences at Swansea University in Wales.