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A biopesticide is a natural substance or organism used to harm, kill, or repel pests. This method of pest control involves using predatory, parasitic, or chemical relationships. Biopesticides come from various sources such as plants, bacteria, other microbes, fungi, and nematodes. They are a key part of integrated pest management (IPM) programs and are gaining attention as alternatives to synthetic chemical plant protection products (PPPs).
Biopesticides Definition
The term “biopesticides” refers to substances used to control agricultural pests through specific biological actions, unlike general chemical pesticides. These products contain biocontrol agents or natural substances derived from animals, plants, bacteria, or certain minerals. They may also include the genes or by-products of these agents.
According to the FAO, biopesticides are considered passive biocontrol agents, unlike active agents such as parasitoids, predators, and various entomopathogenic nematodes.
Many greenhouse farmers in Michigan are discovering that biopesticides can be integrated into their pest management programs alongside natural enemies, which can be purchased commercially. Biopesticides offer several benefits, including lower employee risk, minimal or no re-entry and pre-harvest intervals, and compatibility with biocontrol programs.
Also Check: Bio Medical Waste Management
Biopesticides Examples: One of a biopesticide Example is Bacillus thuringiensis (Bt), a bacterium used to control insect larvae in crops.
Classification of Biopesticides
Biopesticides can be classified into the following categories:
- Biochemical Pesticides: These are natural chemicals that use non-toxic methods to manage pests. Unlike traditional insecticides, which often use synthetic compounds to kill or deactivate pests, biochemical pesticides use methods like insect sex pheromones that disrupt mating or plant extracts that lure pests into traps. Biopesticides examples: Insect sex pheromones.
- Microbial Pesticides: These pesticides have microorganisms (such as bacteria, fungi, viruses, or protozoa) as their active ingredient. Each type targets specific pests, but they can control a variety of pests. For example, certain fungi can kill specific insects or control specific weeds. The most common microbial pesticides come from strains of Bacillus thuringiensis (Bt). This bacterium produces proteins that kill specific insect larvae. Some Bt proteins target only fly and mosquito larvae, while others control moth larvae in crops. Biopesticides examples: Bacillus thuringiensis (Bt).
- Plant-Incorporated Protectants (PIPs): These are pesticides produced by plants that have been genetically modified. Scientists can insert the gene for a Bt pesticide protein into a plant’s DNA. As a result, the plant itself produces the pest-killing protein instead of relying on Bt bacteria. The Environmental Protection Agency (EPA) regulates the protein and its genetic material, but not the plant itself. Biopesticides examples: Genetically modified plants producing Bt proteins.
- Antifeedants: These are chemicals produced by plants to protect themselves from pests. They do not typically affect fundamental plant processes like photosynthesis or growth. Instead, they work against biological pests. These substances are renewable, biodegradable, and can be cost-effective for practical use. Organic farming systems often use biopesticides for pest control. Biopesticides examples: Natural plant chemicals that deter pests.
By understanding the different types of biopesticides, we can make more sustainable and environmentally-friendly choices in pest management.
Biopesticides Examples
Bacillus thuringiensis is a bacterium that can cause disease in certain insects like Lepidoptera, Coleoptera, and Diptera. Its toxin, known as Bt toxin, has been genetically engineered into plants. Manufacturers of Bt toxin claim it has minimal impact on other organisms and is more environmentally friendly compared to synthetic pesticides.
Other microbial control agents include products based on:
- Entomopathogenic fungi such as Beauveria bassiana, Isaria fumosorosea, Lecanicillium, and Metarhizium species.
- Fungi like Trichoderma species and Ampelomyces quisqualis (a hyperparasite of grape powdery mildew) used to control plant diseases. Bacterial agents include Bacillus subtilis and Streptomyces lydicus for plant pathogen control.
- Beneficial nematodes that attack insects (e.g., Steinernema feltiae) or slugs (e.g., Phasmarhabditis hermaphrodita).
- Entomopathogenic viruses like the Cydia pomonella granulovirus.
- Weeds and rodents can also be controlled using microbial agents.
Various animal, fungal, and plant organisms and extracts have been used as biopesticides. Examples of biopesticides include:
- Insect pheromones and other semiochemicals.
- Fermentation products like Spinosad (a macrocyclic lactone).
- Chitosan, which helps plants naturally induce systemic resistance (ISR) to defend against diseases, pathogens, and pests.
Biopesticides may also include natural plant-derived products such as alkaloids, terpenoids, phenolics, and other secondary chemicals. Vegetable oils like canola oil have pesticidal properties. Products based on plant extracts, such as garlic, have been registered for use in the EU and other regions.
Advantages of Biopesticides
- Lower Toxicity: Biopesticides generally have lower toxicity compared to traditional pesticides.
- Targeted Impact: Unlike broad-spectrum conventional pesticides, biopesticides usually target only the specific pest and related species, reducing harm to birds, insects, and mammals.
- Effective in Small Doses: Biopesticides work effectively in small doses and break down quickly, minimizing exposure and pollution.
- Integrated Pest Management (IPM): When used as part of IPM programs, biopesticides can significantly reduce the need for chemical pesticides while maintaining excellent crop yields.
- Knowledge and Adherence: Effective and safe use of biopesticides requires thorough knowledge of pest management and strict adherence to label instructions.
Also Check: Difference Between Herbicides and Pesticides
Disadvantages of Biopesticides
- High Specificity: Biopesticides often need precise identification of the pest or pathogen and may require multiple products to be effective. However, this can also be beneficial as it reduces the risk of harming non-target species.
- Slow Action: They work slowly, making them unsuitable for immediate pest outbreaks.
- Variable Efficacy: Their effectiveness can vary due to several factors since some biopesticides are living organisms that control pests or pathogens by multiplying near or within them.
- Evolving Resistance: Pests and pathogens can develop tolerance to biopesticides. If the target population isn’t completely eliminated, the surviving pests can adapt, leading to an ongoing battle of resistance.
- Unintended Consequences: Broad-spectrum biopesticides can pose risks to non-target species, such as native pollinators like Melipona quadrifasciata in Brazil.
FAQs on Biopesticides
Name five categories of biopesticides.
The five categories of biopesticides are microbial pesticides, insect pheromones, entomopathogenic nematodes, baculoviruses, and plant-derived insecticides.
Give an example of a recently introduced commercial bio-fungicide.
AQ 10® is a recently released bio-fungicide used to control powdery mildew on fruits, especially grapes. It is made from the fungus Ampelomyces quisqualis.
What are Bt-engineered crops?
Bt-engineered crops are genetically modified plants that produce insecticidal proteins from Bacillus thuringiensis (Bt) to control lepidopteran pests.
What are biopesticides and provide examples?
Biopesticides are natural substances or agents derived from animals, plants, and microorganisms such as bacteria, cyanobacteria, and microalgae. They are used to manage agricultural pests and pathogens.
Why are biopesticides important?
Biopesticides are crucial because they are environmentally friendly, do not harm the soil, water supply, or wildlife, including beneficial insects, making them ideal for sustainable agriculture.
Which plants are used as biopesticides?
Plants like neem, garlic, onion, Persian lilac, turmeric, ginger, tobacco, papaya, leucas, pongam, tulasi, aloe, custard apple, vitex, sweet flag, poison nut, and calotropis are used as biopesticides.
Is neem a biopesticide?
Yes, neem acts as a biopesticide. It contains azadirachtin, which inhibits pest feeding, disrupts their growth and reproduction. Neem can also be used as a biofertilizer; neem seed extract acts as organic manure and controls many pathogens.
What are the disadvantages of biopesticides?
The disadvantages of biopesticides include a slower rate of pest kill compared to conventional chemical pesticides, shorter environmental persistence, and susceptibility to unfavorable environmental conditions.
Who uses pesticides?
All farmers, including organic farmers, use pesticides. Organic farmers use pesticides from natural sources, while conventional farmers may use synthetic pesticides. Both types have varying levels of toxicity.
How to make biopesticides?
Biopesticides can be made using the following ingredients by weight: 24-25 parts juice of eggplant stalk, onion, and fistular onion stalk, 14-15 parts juice of chili and pepper, 6-7 parts pine tree leaf alcohol extract, 11-12 parts plant ash leaching liquid, and 4-5 parts potassium sulfate.
Who invented pesticides?
The earliest recorded use of pesticides was around 4500 years ago by the Sumerians, who used sulfur compounds to control insects and mites.
