(a) Ant
(b) Cockroach
(c) Crab
(d) Spider
18. Ans: a
Explanation:
Ants belonging to a South American group had switched from a hunter-gatherer lifestyle to subsistence farming of fungi that grew on decomposing, woody plant matter some 55 to 60 million years ago, shortly after the dinosaurs died out.
There are leaf cutter ants who grow fungus on these leaves, and feed this fungus, and not the leaves to their larvae.
Some ants also use ‘aphids’, a type of insect to get milk like sugary liquid.
Other cultivators of fungi are termites, ambrosia beetles and marsh periwinkles.
Hence, option a is correct.
Read: Previous Year UPSC Environment Questions (PYQs) With Explanation 2022