Bioinsecticides as an application of microorganisms in the field of agriculture
Microorganisms are living organisms that are smaller in size. Observation of them is through microscopes. It is not through our naked eye. The different sizes, shapes, colors, and habitats of microorganisms make immense biodiversity among other microorganism species. Numerous microorganisms are available all around us. Bacteria, fungi, algae, protozoa, viroid, and prions are types of microorganisms. The virus is also classified under microorganisms even though they are considered non-living organisms.
Microorganisms are applied in different fields including agriculture, food production, health, and the environment. Agricultural applications of microorganisms include biofertilizers and bioinsecticides.
Bioinsecticides
What are insects
Since there are some insects that cause harm to crops, those insects are called pests. There are many species that can be called pests. So the pests have a range of biodiversity. In order to prevent the damage by these insects on crops, insecticides are being used.
What are insecticides
Insecticides are composed of numerous organic extracts that show a wide range of characteristic features against insects. Insecticides can be chemically synthesized or naturally occurring.
Chemically synthesized insecticides have many environmental effects since they act on non-targeted beneficial insects. This can be due to the contamination of food or water by these chemicals. It showed the need to have biological control agents to control pest attacks. Therefore, studies were done and found that microbial pathogens can destroy pest species.
Use of Microbial Pathogens as bioinsecticides
Microbial pathogens are microorganisms that can cause diseases among pest populations. These microorganisms are spread in large quantities to the pest populations. Bacteria, viruses, fungi, protozoa, and nematodes can be used as microbial pathogens.
Bioinsecticides as a way of Integrated Pest Management
Integrated pest management is a systematic approach. It combines different crop protection practices with careful monitoring of pests and their natural enemies. Currently, using microorganisms as bioinsecticides is called one of the ways of Integrated Pest Management (IPM).
Classification of bioinsecticides
Based on the active substance, biopesticides are categorized into three different types as follows
- Microbial biopesticides
- Biochemicals
Biochemicals include a wide variety of secondary metabolites produced by plants. The herbivores that feed on these plants can be killed. For example, pyrethrins are produced by Chrysanthemum cinerariaefolium, which is a fast-acting compound.
- Semiochemicals
Semiochemicals are chemical signals derived by one organism. These have the potential to cause behavioral changes in an individual. That individual can be from the same species or a different species.
Bioinsecticide is a better solution for small-scale farmers in order to avoid pest attacks on stored grains. Further, these are risk-free for both humans and the environment. There is no threat to non-targeted species. Therefore, microbial insecticides can be called the best alternative to chemical insecticides.
There are types of bioinsecticides like entomopathogenic bacteria. For example, Bacillus thuringiensis (BT) subspecies are used as insecticides. The use of biopesticides plays an important role in the sustainability of the agricultural economy. There are many ecosystem benefits received from the use of biopesticides. Bioinsecticides show both advantages and disadvantages.
Disadvantages associated with biopesticide application
Since biopesticides are safe to use, specific, compatible with other methods, and in non-hazardous and natural establishments, these are beneficial to use. But there are disadvantages.
- When toxic on a specific species, other species would damage the crops.
- Ultraviolet radiation and heat can affect the effectiveness of microbial insecticides. When applying, we have to apply in the morning.
- External environmental conditions like temperature, relative humidity, and rainfall can affect the effectiveness.
Bioinsecticides show advantages over disadvantages. However, these are still less efficient than chemically synthesized insecticides. Therefore the efficacy of these insecticides needs to be improved greatly at a lower cost.