Q. Consider the following kinds of organisms:
- Bacteria
- Fungi
- Flowering plants
Some species of which of the above kinds of organisms are employed as biopesticides? (UPSC Prelims 2012)
Answer:
1, 2 and 3
Notes: The correct answer is
[D] 1, 2 and 3. Biopesticides are certain types of pesticides derived from such natural materials as animals, plants, bacteria, and certain minerals. They are grouped into three major categories: biochemical pesticides, microbial pesticides, and plant-incorporated protectants.
- Bacteria (Point 1 is Correct): Many bacterial species are used as biopesticides. The most common is Bacillus thuringiensis (Bt). It produces a protein that is toxic to the digestive systems of specific insects (like caterpillars and beetles). Other examples include Pseudomonas fluorescens used to control soil-borne pathogens.
- Fungi (Point 2 is Correct): Several fungi act as entomopathogenic agents (killing insects) or bio-fungicides. For example, Beauveria bassiana is widely used to control aphids, whiteflies, and thrips. Trichoderma species are used to control various plant diseases caused by other fungi.
- Flowering Plants (Point 3 is Correct): Many flowering plants produce natural chemicals that act as pesticides. Neem (Azadirachta indica) is a prime example; it contains azadirachtin, which disrupts the life cycle of insects. Pyrethrum, derived from the flowers of certain Chrysanthemum species, is another well-known botanical pesticide. Additionally, through genetic engineering, the insecticidal genes from bacteria can be incorporated into the DNA of flowering plants (Plant-Incorporated Protectants).