UPSC Prelims 2017 Question:

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 using the code given below:

Explanation: 

• Butterflies are natural pollinators as they feed on the flowers and enable pollination or fertilization.
  
  
• Pollination is among the most visible and important ecosystem services and is necessary for reproduction of 60–70% of all plant species and 35% of global crop production. If the population of natural pollinators decreases, there will be a corresponding decrease in the pollination. Thus, statement 1 is correct.
  
  
• This can adversely affect the population of species of wasps, spiders and birds, given they are part of a food chain and food web. So, statement 3 is correct.
  
  
• However, there cannot be any direct correlation between rise in fungal infections and decrease in the population of butterflies. So, statement 2 is not correct.
  
  

Therefore, option (3) is the correct answer.

Subject: Science & Technology | Biodiversity and Conservation