Option C is correct becose i will eliminate one by one option ,according to ncert Baculoviruses show against effect on insects and arthropods.. hear late blite of potato is caused by phytoptera infestinalis (fungus) soo we will easly eliminate this option, dragon fly is used for get rid of aphids..but in qution they are asking about microbes.. soo we will eliminate this option also.. Gambutia is a fish use full to get rid of masqutos.. trichoderma is fungus it shows effects on several plant pathogens... so.. option C is correct..

Biological control of pests using microbes is an environmentally friendly and sustainable approach to manage pest populations. Microbes such as bacteria, fungi, and viruses can be used to control pests by infecting and killing them or by disrupting their life cycle. Among the given options, option 'C' which states "Trichoderma against several plant pathogens" is the correct example of biological control of pests using microbes. Trichoderma is a genus of fungi that has been widely used as a biocontrol agent against various plant pathogens.

Explanation:
Trichoderma is a beneficial fungus that can colonize the roots and surrounding soil of plants. It is known for its ability to suppress the growth of a wide range of plant pathogens, including fungi, bacteria, and nematodes. Trichoderma acts as a biocontrol agent by competing with pathogens for nutrients and space, producing antifungal compounds, and inducing systemic resistance in plants.

The main mechanisms by which Trichoderma controls plant pathogens are as follows:

1. Competition: Trichoderma colonizes the root system and forms a protective barrier, preventing the entry of pathogens. It competes with the pathogens for nutrients and space, limiting their growth and establishment.

2. Antibiosis: Trichoderma produces a variety of antifungal compounds, such as enzymes, antibiotics, and volatile organic compounds, which inhibit the growth and development of plant pathogens. These compounds can either directly kill the pathogens or suppress their virulence.

3. Induced systemic resistance: Trichoderma can stimulate the plant's immune system, enhancing its resistance against pathogens. It triggers the plant's defense mechanisms, such as the production of defensive enzymes and phytoalexins, to protect it from pathogenic attacks.

4. Mycoparasitism: Some species of Trichoderma are mycoparasites, which means they can directly attack and parasitize other fungi. They penetrate the hyphae of the pathogenic fungi, causing their destruction and ultimately leading to their death.

Trichoderma-based biocontrol products are commercially available and have been successfully used to control various plant diseases, including damping-off, root rot, wilt, and foliar diseases. This approach offers several advantages over chemical pesticides, such as being safe for humans, animals, and the environment, as well as being sustainable and cost-effective.

In conclusion, Trichoderma is an excellent example of biological control of pests using microbes. It effectively suppresses plant pathogens through competition, antibiosis, induced systemic resistance, and mycoparasitism. This approach provides a sustainable and environmentally friendly alternative to chemical pesticides in agriculture.