Microbe used for biocontrol of pest butterfly caterpillars is :
- Streptococcus sp.
- Trichoderma sp.
- Saccharomyces cerevisiae
- Bacillus thuringiensis
Answer
(4) Bacillus thuringiensis
Solution
As per NCERT, the bacterium Bacillus thuringiensis (Bt) is used to control butterfly caterpillars.
Spores of Bt are mixed with water and sprayed on vulnerable plants; the insect larvae eat them, the toxin is released in their gut and the larvae get killed, while other insects remain unharmed.
Trichoderma, by contrast, is a free-living fungus used against plant pathogens, and Saccharomyces cerevisiae is baker's/brewer's yeast.
Answer: (4)