Question

Which of the following statements is correct? 
(i) Baculoviruses are considered best members for species-specific, short-spectrum insecticide applications. 
(ii) Bacillus thuringiensis is used to control butterfly caterpillars. 
(iii) Use of ladybirds is very beneficial in getting rid of mosquitoes. 
(iv) Trichoderma fungi are used in the treatment of diseased animals under biocontrol. 

Hint:

For biocontrol, it's important to match the biological agent with its specific target species for effective control.

Answer 1

Step 1: Baculoviruses are indeed species-specific and have a narrow host range, making them effective for use in short-spectrum insecticide applications. This is a correct statement. 

Step 2: Bacillus thuringiensis (Bt) is a bacterium that produces toxins harmful to certain insects, including butterfly caterpillars. Hence, statement (ii) is also correct.

 Step 3: Statement (iii) is incorrect as ladybirds are beneficial in controlling aphids and other pest insects, not mosquitoes. 

Step 4: Trichoderma fungi are used in biocontrol, but primarily for controlling plant pathogens, not for treating diseased animals. Therefore, statement (iv) is incorrect.