Explain contribution of microbes in Bio-control of pests and diseases.

Explanation

The very familiar beetle with red and black markings the Ladybird and Dragonflies are useful to get rid of aphids and mosquitoes. An example of microbial biocontrol agents that can be introduced in order to control butterfly caterpillars is the bacteria Bacillus thuringiensis (often written as Bt). They are available in sachets as dried spores which are mixed with water and sprayed onto vulnerable plants such as brassicas and fruit trees. Where these are eaten by the insect larvae. In the gut of the larvae, the toxin is released and the larvae get killed. The bacterial disease will kill the caterpillars, but leave other insects unharmed. Because of the development of methods of genetic engineering in the last decade or so, the scientists have introduced B. thuringiensis toxin genes into plants. Such plants are resistant to attack by insect pests. Bt-cotton is one such example. A biological control being developed for use in the treatment of plant disease is the fungus Trichoderma. Trichoderma species are free living fungi that are very common in the root ecosystems. They are effective biocontrol agents of several plant pathogens. Baculoviruses are pathogens that attack insects and other arthropods. They are included in the genus Nucleopolyhedrovirus. These viruses are excellent candidates for species, specific, narrow spectrum insecticidal applications. They have been shown to have no negative impacts on plants, mammals, birds, fish or even on non target insects. So this is especially desirable when beneficial insects are being conserved to aid in an overall Integrated Pest Management (IPM) programe or when an ecologically sensitive area is being treated.