Explain the role of three organisms as biocontrol agents.

Explanation

1. The Ladybird (a familiar beetle with red and black markings) and Dragonflies are useful to get rid of aphids and mosquitoes respectively.
2. Bacillus thuringiensis (Bt) used to control butterfly caterpillars. Dried spores 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 toxinis released and the larvae get killed.
3. Trichoderma a free living fungus used to control several plant pathogens.
4. Baculoviruses are pathogen that attack insects and other arthropods. The majority of Baculoviruses used as biological control agents are in the genus Nucleopolyhedrovirus. These viruses are excellent candidates for species-specific, narrow spectrum insecticidal application. They have no negative impacts on plants, mammals, birds, fish, etc. This is very useful in integrated pest management programme (IPM).