Due to some reasons, if there is a huge fall in the population of species of butterflies, what could be its likely consequence/consequences ? 1. Pollination of some plants could be adversely affected. 2. There could be a drastic increase in the fungal infections of some cultivated plants. 3. It could lead to a fall in the population of some species of wasps, spiders and birds. Select the correct answer using the code given below :
- (a) 1 only
- (b) 2 and 3 only
- (c) 1 and 3 only ✓ UPSC's answer
- (d) 1, 2 and 3
Why the answer is (c)
• Butterflies are pollinators of many flowering plants, so a crash in their numbers would hurt pollination of some species (1).
• Butterflies and their caterpillars are prey for parasitic wasps, spiders and insectivorous birds; losing them would reduce those predators' populations (3).
• Statement 2 is wrong: butterflies neither control nor spread fungal infections, so their decline has no direct link to fungal disease in crops.
• Hence 1 and 3 only, option (c).
Why the other options are wrong
- (a) 1 only
- Statement 3 on predator decline is also correct.
- (b) 2 and 3 only
- Statement 2 is wrong: no link to fungal infections.
- (d) 1, 2 and 3
- Statement 2 is wrong.
Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2017, held on 18 June 2017. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.