General Science

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.