Introduction
Chemicals called pesticides are compounds used to eradicate pests. A pesticide is typically a chemical or biological agent such as a virus, bacterium, antibiotic, or disinfectant that inhibits, renders ineffective, or kills pests.
In the United States, The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) mandates that the Environmental Protection Agency (EPA) examine a pesticide’s intended usage to ensure that there are no unreasonable hazards to human health and the environment. Only then can the pesticide be marketed and used in the country.
Weeds, plant diseases, and invertebrate pests are controlled with biopesticides. The microorganisms utilised include bacteria, yeasts, fungus, and viruses.
Biopesticides pose minimal dangers to individuals and the environment, making them a relatively safer alternative to chemical or chemical-derived pesticides. Environmental safety and host specificity are the main benefits of biopesticides in managing agricultural pests.
Table of Contents
- What Are Biopesticides?
- Importance of Biopesticides
- Classification of Biopesticides
- Advantages of Biopesticides Usage
- Examples
- Frequently Asked Questions (FAQs)
What Are Biopesticides?
The word “biopesticides” refers to compounds that, as opposed to general chemical pesticides, are used to control agricultural pests through specialised biological effects. Used to manage pests, biopesticides refer to products containing biocontrol agents, natural entities or chemicals produced from natural materials (such as animals, plants, bacteria, or specific minerals). These agents may also include their genes or metabolites.
The FAO defines biopesticides as passive biocontrol agents, compared to those that actively seek out the pest, such as parasitoids, predators, and numerous types of entomopathogenic nematodes.
Large numbers of greenhouse farmers in Michigan are learning that biopesticides can be employed in their integrated pest management (IPM) programs in addition to naturally occurring enemies that can be bought commercially. Growers can benefit from several advantages provided by biopesticides such as lower employee risk, negligible (or no) re-entry and pre-harvest intervals, and compatibility with biocontrol programs.
Importance of Biopesticides
Most farmers attempting to establish a sustainable farming system know that the chemical shed is not their first line of defence against unwanted pests. A “softer” biopesticide or a conventional, synthetic treatment are the farmer’s two options when a pest infestation gets too serious, and a chemical application is required. The Integrated Pest Management (IPM) program combines cultural measures, biological controls (such as predatory insects), and chemical control to keep pest populations under control.
Biopesticides are more environmentally friendly and do not harm the soil, water supply, or wildlife, including beneficial insects, which is one of the main advantages of introducing them into a sustainable agriculture system.
Biopesticides are typically used in rotation with conventional products rather than as a replacement, which reduces the amount of synthetic chemicals used. Insects and diseases develop resilience to synthetic chemicals over time. The effectiveness of the synthetic chemical is increased by alternating it with biopesticides.
- Some inoculants with bacteria are made using the fermentation method. Before planting, these inoculants are sprayed on the seeds, and some of them are released into the plants.
- In organic farming, a solution of Azotobacter and synthetic nitrogenase is used to control different insects, weeds, and nematodes.
- The use of biopesticides protects against fluoroacetamide and other chemicals from contaminating the soil. Additionally, they are less likely to affect both human and animal skin.
- Biotechnology enables the direct incorporation of bacterial and fungi toxins that can kill infections and pests into plants. Similar to bacteria, some fungus and virus species have pesticide properties. A biopesticide called spinosad is produced during fermentation.
Despite the potential benefits of using biopesticides, their usage has not been as popular as expected for the following reasons:
- Expenses associated with creating, testing, and obtaining regulatory approval for new biological agents contribute to the high cost of pesticide manufacture.
- Due to regional and climatic changes in humidity, temperature, soil conditions, etc., there is limited field effectiveness.
- Farmers are hesitant about biopesticides because of their high specificity, which means that they only work against specific pathogens and pests.
- Multiple biological agents are used in biopesticides to manage a variety of insects and pests in the field. These treatments are difficult to use, expensive, and inconvenient, and they are not suitable for many pests and pathogens.
- Because biopesticides are sensitive to changes in temperature and humidity, they have a short shelf life.
Classification of Biopesticides
Biopesticides can be classified into the following classes:
- Biochemical Pesticides: Natural chemicals called biochemical pesticides use non-toxic ways to manage pests. Contrarily, conventional insecticides often consist of synthetic compounds, directly killing or inactivating the pest. Insect sex pheromones and other compounds that prevent mating, and different aromatized plant extracts attracting pests to traps are examples of biochemical insecticides.
- Microbial Pesticides: A microorganism (such as a bacterium, fungus, virus, or protozoan) serves as the active component of microbial pesticides. Although each active ingredient in microbial pesticides is specialised for its intended pest(s), they can control many pests. For instance, certain fungi kill particular insects, while others control specific weeds.
Strains and subspecies of Bacillus thuringiensis (Bt) are the most widely utilised microbial pesticides. This bacterium creates several protein combinations, each of which mainly kills one or a small number of related insect larvae species. While some Bt components only target fly and mosquito larvae, other Bt components also control moth larvae in plants.
- Plant-Incorporated Protectants (PIPs): Plants can be manipulated to create pesticides called Plant-Incorporated-Protectants (PIPs) from genetic material, incorporated into the plant. For instance, researchers can insert the gene for the Bt pesticide protein into the plant’s genetic makeup. The plant produces the pest-killing component rather than the Bt bacteria. EPA regulates the protein and its genetic makeup but not the plant itself.
Antifeedants are a term used to describe a variety of chemical substances that plants create to defend themselves against pests. In most cases, photosynthesis, growth, or other fundamental components of plant physiology are not known to be affected by biopesticides. They function against biological pests instead. These materials are renewable and biodegradable alternatives that may be cost-effective for practical use. Organic farming systems make use of this method of pest control.
Advantages of Biopesticides Usage
- When compared to traditional pesticides, biopesticides generally have lower intrinsic toxicity.
- Contrary to broad-spectrum, conventional pesticides, which can impact a variety of organisms, including birds, insects, and mammals, biopesticides often only affect the target pest and closely related organisms.
- Biopesticides work primarily in minimal doses and often degrade quickly, reducing exposure levels and mainly avoiding the pollution issues caused by chemical pesticides.
- Biopesticides can significantly reduce the use of chemical pesticides while maintaining excellent crop yields when utilised as a part of Integrated Pest Management (IPM) programs.
However, users must be highly knowledgeable about managing pests and strictly adhere to all label instructions to use biopesticides efficiently (and safely).
Examples
A well-known example of a biopesticide is the bacteria Bacillus thuringiensis, which may infect Lepidoptera, Coleoptera, and Diptera. The B. thuringiensis toxin (Bt toxin) has been directly integrated into plants through genetic engineering. Its producers assert that it is less harmful to the environment than synthetic pesticides and has little impact on other living things. It is questionable if Bt toxin should be used.
Another biopesticide used is Pyrethrin.
Several other types of bio-insecticides and bio-pesticide are:
- Cow Urine
- Fermented curd water
- Neem -cow urine extract
- Mixed leaves extract
- Chilli –garlic extract
Related Links:
- MCQs on Biopesticides
- Which is Used as Biopesticide?
- What is Biopesticide and Its uses?
- What Microbes Are Used as Biopesticides?
- What Are Biopesticides? Name Any Two Biopesticides?
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