Question

Identify the microorganism which is commercially exploited as the source of bioinsecticides.
A. Chrysanthemum cinerariifolium
B. Phytophthora palmivora
C. Bacillus thuringiensis
D. Both (a) and (c)

Answer 1

Hint: Biopesticides are certain kinds of pesticides derived from such natural materials like plants, animals, bacteria, and certain minerals. For example, baking soda and canola oil have pesticide applications and are considered biopesticides.


Complete step-by-step answer:

Bacillus thuringiensis (Bt) is a species of bacteria that resides in soil. It creates proteins that are toxic to some insects when consumed, but not others. The proteins are not toxic to people because, like all mammals, we can't activate them. Bt is not toxic to non-target wildlife. B.t. works through a well-known protein mechanism that causes toxicity in caterpillars (i.e. insect larvae). This mechanism is not known to be found in humans or other mammals. B.t. is a biological control technique that is an alternative to chemical pesticides.
Pyrethrum flowers of the genus Chrysanthemum cinerariifolium are cultivated in Kenya by small-scale farmers to extract pyrethrins, a natural insecticide’s active ingredient. Pyrethrins are classified into two groups, Pyrethrins I and II, and are degradable when exposed to moisture, air, and high temperatures.
Phytophthora palmivora is an oomycete that causes fruit-rot, bud-rot of palms, or kole-roga of coconut and areca nut. These are among the most serious diseases caused by moulds and fungi in South India.


Therefore the correct answer is Option C.
Note: A bacterial species namely Bacillus thuringiensis is known to kill a wide range of insects like mosquitoes, beetles, ants etc. It is a bioinsecticide. Bt works as an insecticide by producing a crystal-shaped protein (Cry toxin) that specifically kills certain insects.