Which one of the following shows a unique relationship with an insect that has coevolved with it and that is the only insect that can pollinate this tree ?
- (a) Fig ✓ UPSC's answer
- (b) Mahua
- (c) Sandalwood
- (d) Silk cotton
Why the answer is (a)
• Fig trees (Ficus) and fig wasps (family Agaonidae) have coevolved for about 80 million years in an obligate mutualism: each fig species is pollinated by its own specific wasp species.
• The female wasp enters the enclosed fig (syconium) through a tiny opening, pollinates the hidden flowers and lays her eggs; the fig provides a nursery, and the wasp is the sole pollinator — option (a).
• Mahua is pollinated by bats and other visitors; sandalwood by various insects; silk cotton (semal) by birds and bats — none has a single obligate insect pollinator.
• Figs are 'keystone species' because they fruit year-round and feed many animals.
• Hence option (a).
Why the other options are wrong
- (b) Mahua
- Mahua is pollinated mainly by bats, not one coevolved insect.
- (c) Sandalwood
- Sandalwood has generalist insect pollinators.
- (d) Silk cotton
- Silk cotton is pollinated by birds and bats.
Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2024, held on 16 June 2024. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.