Biopesticides

• Biopesticides are pesticides that are synthesized from natural sources such as animals, plants, bacteria, or certain minerals. These natural substances are used to control pests in an eco-friendly and non-toxic manner. Some examples of biopesticides include fungi like Beauveria species, bacteria like Bacillus species, neem extracts, and pheromones derived from certain plants. Other materials like canola oil, tea tree oil, cayenne pepper, neem cake, and extracts from lemongrass or baking soda are also known to have pesticidal properties.
• In essence, biopesticides are products derived from naturally occurring substances, providing an alternative to conventional chemical pesticides. They are designed to control pests without causing harm to non-target organisms and are generally safer for humans, animals, and the environment. Additionally, biopesticides support sustainable pest management by being a crucial part of Integrated Pest Management (IPM) programs.

Types of Biopesticides

Biopesticides are classified into five main types:

Biochemical Pesticides These are naturally occurring substances such as plant extracts that control pests through non-toxic mechanisms. Unlike conventional chemical pesticides that kill or inactivate pests, biochemical pesticides can disrupt mating (e.g., insect sex pheromones), attract pests through scents, or use traps.

Microbial Pesticides Microbial pesticides use microorganisms such as bacteria, fungi, viruses, or protozoa as the active ingredient to control pests. Each microorganism is generally specific to a target pest. A well-known example is Bacillus thuringiensis (Bt), which produces proteins that are toxic to specific insect larvae (e.g., moth or fly larvae).

Plant-Incorporated Protectants (PIPs) PIPs are pesticidal proteins produced by plants through genetic modification. These plants synthesize proteins that kill pests when they feed on the plant. For instance, Bacillus thuringiensis genes have been incorporated into crops to protect against pest larvae such as Helicoverpa.

Botanical Pesticides These are derived from plants and have traditionally been used for pest control. Examples include neem and pyrethrum. Other plant-based pesticides include nicotine, rotenone, and azadirachtin (from neem), which can disrupt pests’ reproductive and digestive systems.

Biotic Agents (Parasitoids and Predators)

1. • Predators: These organisms, such as beetles, flies, spiders, and predatory mites, consume pests during their development. They may specialize in a particular pest or eat a variety of pests.
   • Parasitoids: Parasitoids are insects that lay eggs inside a host. The larvae feed on the host’s tissues, eventually killing it. Notable examples include Trichogramma, Encarsia, and Bathyplectes.

Advantages of Biopesticides

1. Reduced Toxicity: Biopesticides are generally less toxic than conventional chemical pesticides, reducing health risks to users and the environment.
2. Target Specificity: Biopesticides are typically specific to the target pest, unlike broad-spectrum chemical pesticides, which can affect a range of organisms, including beneficial ones such as bees, birds, and mammals.
3. Decomposability: Biopesticides are often effective in small amounts and degrade quickly, reducing long-term exposure and preventing environmental pollution.
4. Compatibility with IPM: As a key component of Integrated Pest Management, biopesticides reduce the need for chemical pesticides while maintaining crop yields, supporting sustainable agriculture.