Down in Jungleland: How the mighty banyan is nothing without the tiny wasp

The relationship between the wasps and different types of ficus can be pretty complex. But, what is astonishing is the fact that every species of fig tree has its own special designer species of fig wasp to pollinate it.

Written by Ranjit Lal | Updated: June 11, 2017 11:44 am
The peepal is also a beautiful tree and its heart-shaped leaves should surely be used as tokens of love!

Try and research the ficus (alias fig) family, and you’ll come out with your head spinning. There are apparently anything between 750 and 1,000 members of this mainly tropical clan spread worldwide, and they seem to have guarded their secrets well — because all the various sources I scanned didn’t exactly have the same script, even if the leading characters were the same. Even so, the main scandals and sensational aspects of their lives remained consistent — thank God for small mercies.

The first time I was made aware of the clan’s Jekyll and Hyde character was in Corbett National Park. We’d stopped next to this gigantic, strange-looking tree that towered above us. It had an enormous girth, it looked like a banyan but it didn’t seem to have a solid trunk. Innocently, we asked what it was.

“Strangler fig,” was the laconic reply. “It’s got roots but see, it is absolutely hollow in the centre.”

“What?”

And that’s when we discovered the tree’s diabolical secret. A bird, a hornbill, perhaps, had indulged in figs a long, long time ago — and you know what that can do. A sticky seed, hastily voided, landed on the tree that had originally been growing here and quickly sent roots down and shoots up. Once these roots — called prop roots — reached the ground, they strengthened themselves and began sending nutrients back up to the shoots which got nice and leafy, making yet more food. Other roots began twining around the host tree’s bark and tapping into its food supply lines. These grew fatter and stronger as they garroted the host, like a python’s coils working in ultra-slow motion, except that these roots not only squashed the life out of its host, but sucked it out of it too. This was really a diabolical tree.

But peepals and banyans (the two most famous and popular of this clan in India) are also revered — and the Buddha is said to have attained enlightenment under a peepal tree. One very famous banyan is said to have provided shade to 20,000 people, such was its generosity. Besides, in the tropical forests, the great banyans are known as a “keystone” species, because a myriad number of birds, animals and reptiles depend on their figs and leaves, and use the trees as homes. They fruit throughout the year, providing an assured food supply. The peepal is also a beautiful tree and its heart-shaped leaves should surely be used as tokens of love! On the hottest, stillest afternoons, its leaves will catch the slightest movement of air and fan you —rustling softly, almost as if powered by their own miniature motors. The peepal is the lady and the banyan is the gentleman, and they must be grown together. So, were these ostensibly lovely trees, terrible stranglers too? Again, I was flummoxed, because one authoritative source said they were stranglers and another said they were not!

However, all the sources agreed with one blockbuster fact: the unique symbiotic relationship the ficus has with a tiny (1 mm long) black insect, called the fig wasp. The deal is simple but the complexities of exactly what goes on is something I still haven’t quite wrapped my head around. The bare bones deal: the little wasp pollinates the tree — and the tree allows (in most cases) the wasp to lay its eggs and have its babies inside its flowers. The ficus flowers, in their hundreds (which may be male, female or sterile ‘gall’ flowers!), are actually contained in a little pouch, which is called the syconium, and access to which is permitted through a tiny hole at its top. Lady wasps, expecting a happy event, squeeze through, lay their eggs inside the gall flowers and die.

The eggs hatch and the larvae (which feed on the flowers) of little boy wasps emerge first. Frantic, the wasps mate with the girl wasps that hatch later. Their life work complete, the males die and the little girl wasps, already pregnant, squeeze out of the fig, anointing themselves with pollen from the male flowers, which live near the entrance. They search for another fig tree to have their babies and when they find one, squeeze in and pollinate the female flowers with the pollen they’re carrying, leading to seed formation. Birds and animals eating the figs do the needful in scattering the seeds away (but not too far away) from the parent tree. Be warned, this is a relatively simplistic version of what happens — the relationship between the wasps and different types of ficus can be pretty complex.

But, what is astonishing is the fact that every species of fig tree has its own special designer species of fig wasp to pollinate it, which means there are probably 750 to 1,000 species of specialised fig wasps. It really makes you wonder if Mother Nature has got her head screwed on right. Here you have this grand old tree — the banyan — on which the entire forest depends for its existence and well-being (even if it is a tree-murderer). Under its shade, 7,000 soldiers of Alexander the Great are also said to have rested. The grand old tree is entirely dependent for its survival on this miniscule 1 mm long wasp! If something catastrophic happens to the wasp, it’s curtains for the banyan — and then the whole forest!

For a banyan with a big ego, there couldn’t be a bigger takedown. For us, well, maybe a reminder to think twice before we casually step on even the smallest, most inconsequential-looking creatures!

Ranjit Lal is an author, environmentalist and bird watcher.

For all the latest Lifestyle News, download Indian Express App

  1. No Comments.