The biological control method involves the use of the living organisms which act as the predators for the pests and harmful insects. The main advantage of the biological control method in the control of agricultural pests is that they are self-perpetuating. Biological control, often referred to as “biocontrol”, is a method of reducing or eliminating the impact or damage caused by a target pest or weed using a biocontrol agent, traditionally a predator, herbivore or pathogen. So, microbial agents are highly specific against target pests so they facilitate the survival of beneficial insects in treated crops. This may be the main reason that microbial insecticides are being developed as biological control agents during the last three decades. Biological control is less costly and cheaper than any other methods biocontrol agents give protection to the crop throughout the crop period and they do not cause toxicity to the plants and an application of biocontrol agents is safer to the environment and to the person who applies them.

Microorganism abacterium, fungus, virus or protozoan as the active ingredient can control many different kinds of pests, although each separate active ingredient is relatively specific for its target pest. As there are fungi that control certain weeds, and other fungi that kill specific insects. Biological control includes the use of predators, competitors, pathogens and compounds of biological origin. Microorganisms used include viruses, bacteria, fungi and protozoans. These may cause disease, or may compete with or otherwise limit the target organism. Biological controls tend to be highly specific.Biocontrol is a method of controlling pests, such as insects, mites, weeds, and plant diseases, using other organisms. It relies on predation, parasitism, herbivory, or other natural mechanisms, but typically also involves an active human management role. The soil bacterium Bacillus thuringiensis (Bt) produces endotoxins during sporulation that have specific toxicity to several insect species. The inactive crystal protein is enzymatically converted to an active toxin inside an insect's gut. Alongside the use of disease-resistant cultivars, biological control is seen to have an important role in integrated pest management strategies aimed at reducing the use of chemical pesticides. A BCA is an organism or collection of organisms rather than a chemical per se. regulating the Ecosystem to Protect and Promote Natural Enemies or Competitors of Pathogens. Plant disease often results from a disordered ecosystem. The success of biological control relies on a healthy ecosystem provided by predators, competitors, promoters, and other species. Biological control uses a living organism to kill pests while chemical control uses different strong chemicals to kill, prevent or repel pests. Therefore, biological control is an eco-friendly method since it does not harm the environment and people while chemical control is not environmental friendly.

Alongside the use of disease-resistant cultivars, biological control is seen to have an important role in integrated pest management strategies aimed at reducing the use of chemical pesticides. A BCA is an organism or collection of organisms rather than a chemical per se. Microorganism e.g., a bacterium, fungus, virus or protozoan as the active ingredient can control many different kinds of pests, although each separate active ingredient is relatively specific for its target pest and there are fungi that control certain weeds, and other fungi that kill specific insects. Biological control is the use of natural enemies to reduce the numbers of a damaging organism, which can be anything from a bacterium to a rabbit. Such natural enemies include pathogenic and competitor microorganisms. Biological control, often referred to as “biocontrol”, is a method of reducing or eliminating the impact or damage caused by a target pest or weed using a biocontrol agent, traditionally a predator, herbivore or pathogen. The biological control method involves the use of the living organisms which act as the predators for the pests and harmful insects. The main advantage of the biological control method in the control of agricultural pests is that they are self-perpetuating. Biological control involves the mass-production and release of natural enemies such as parasitoids and predators to control pest insects in an environmentally sound manner. Radiation is used to increase the applicability, cost-effectiveness and safety of rearing, shipping and deploying such natural enemies. Biological control is the use of living organisms to suppress pest populations, making them less damaging than they would otherwise be. Natural enemies of insects play an important role in limiting the densities of potential pests. The principal attributes of an effective biological control agent are: efficient searching ability, high parasitism or predation rate, high reproductive potential, minimal handling time, ability to survive at low prey densities and ability to adapt to a wide range of environmental conditions.