Q. 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? (UPSC Prelims 2024)
Answer:
Fig
Notes: The correct answer is
[A] Fig. The relationship between the fig tree (
Ficus species) and the fig wasp (family
Agaonidae) is one of the most classic examples of
obligate mutualism and
coevolution in the biological world.
- Fig (Ficus): Each species of fig tree is typically pollinated by a specific, unique species of tiny wasp. The fig "fruit" is actually a syconium—a hollow, enclosed inflorescence with hundreds of tiny flowers inside. Because the flowers are hidden inside this structure, they are inaccessible to general pollinators like bees or butterflies.
- The Wasp's Role: The female fig wasp enters the syconium through a tiny opening called an ostiole. Once inside, she pollinates the flowers while simultaneously laying her eggs in some of them.
- Mutual Benefit: The wasp larvae develop inside the galls formed within the fig, using it as a nursery and food source. In return, the tree is successfully pollinated, ensuring the production of seeds. Neither the tree nor the wasp can complete their life cycle without the other.
- Mahua (Madhuca longifolia): This tree is primarily pollinated by birds (ornithophily) and bats, as its flowers are rich in nectar. It does not have an exclusive single-insect relationship.
- Sandalwood (Santalum album): It is a partial root parasite that is pollinated by a variety of insects, including bees, butterflies, and ants.
- Silk Cotton (Bombax ceiba): This tree has large, sturdy red flowers designed for pollination by birds and sometimes bats, but it is not dependent on a single, specific insect species.