BBC - Earth - A tale of loyalty and betrayal, starring figs and wasps
He defined commensalism as a relationship between two Each fig species has its own unique fig wasp pollinator; in addition, there are. Mutualism: The intimate relationship between fig trees and fig wasps ( appropriately) 'mutualism' and there are numerous examples all over the world. The female fig wasp, once she's found a host tree, squeezes through a. Interaction of figs and fig wasps inside figs, a relationship that is a classic example of an obligate mutualism (neither party can between fig tree and wasp does not always hold, so the interaction is not as well defined as initially appears.
We humans also engage in mutualism with other species—we shelter and provide food to the flora in our gut, for instance, without which we cannot digest food efficiently. The term was introduced by Belgian zoologist Pierre Joseph van Beneden in His book classified relations between species of animals as parasitism, commensalism and mutualism. He defined commensalism as a relationship between two organisms in which one benefits but the other is not affected and mutualism as one in which both benefit.
But in the fig tree-fig wasp relationship, the barter is not as simple as it seems. Each fig species has its own unique fig wasp pollinator; in addition, there are parasitic wasps that inhabit the microcosm.
The fig also has nematodes, which are small worms that hitchhike on pollinator fig wasps to move from one fruit to another.
These savvy hitchhikers know which wasps to target by the smell and taste of each fig species. Fascinated by the intricacy of the fig and fig wasp system, I asked if I could have a live demonstration.
What Is the Symbiotic Relationship between Fig Wasps & Figs?
Yathiraj and post-doctoral fellow Lucy Nongbri—accompanied me to show me the fig trees on the campus, where they are conducting their studies.
There are 55 fig trees of the species Ficus racemosa spread throughout the IISc campus. The team was leading me to a tree which had recently been penetrated by fig wasps.
In the midst of the buildings, there stood a tall, majestic tree stood, laden with bunches of small spherical green structures, no bigger than grapes.
These are called synconia; they contain the flowers of the fig tree. A single syconium can hold hundreds or thousands of flowers.
What Is the Symbiotic Relationship between Fig Wasps & Figs? | Animals - webob.info
This tree is monoecious—that is, both male and female flowers are present in the same syconium in the same tree. The female flowers mature first and, when they are ready to receive pollen, volatile fragrances waft out from the syconium, attracting the fig wasp.
Drawn by the scent, a female wasp carrying pollen from its previous host enters the syconium through a tiny opening in the centre. The fig wasp, about 2mm in size, can easily pass through the eye of a needle, but the syconium opening is even narrower.
- Sending a Signal
- Follow BBC Earth
- Accessibility links
As it enters, its wings break off and its abdomen gets squished as it makes its long slow crawl into the syconium. Deepa Padmanaban The fig tree then closes the opening and seals it with an antiseptic liquid to prevent other insects from getting in—in the process, turning it into a death trap for the wasp. Once inside, the wasp lays its eggs in the female flowers, simultaneously depositing the pollen. Tired and wounded from the long gruelling journey down the syconium, the wasp is on its last leg of life.
After the eggs hatch, these galls provide food and shelter for the young offspring. Gupta, the doctoral student, plucked one of the synconia from the tree, deftly splitting it into two. Inside, I could see hundreds of fat swollen galls, each probably nurturing eggs inside.
A few that had already hatched were feeding on the galls. Deepa Padmanaban Once these offspring attain adulthood, the male and female wasps mate within the fig; the blind and wingless male wasps then cut an opening, allowing the female wasp to fly out.
Around the same time, the male flowers are getting ready. The female wasps collect the pollen from the male flower and leave, starting another life cycle. The syconium now contains only lifeless and wingless male wasps and goes on to ripen.
The mature fruit containing fully developed seeds are consumed by birds and monkeys, which also help in the dispersal of seeds. This entire cycle lasts for about two months.
So, the research team surveys all the fig trees on campus once a week in order to keep a check on the phase of the tree. This is important for them to design and conduct experiments and to avoid missing the stages of both the wasp and syconium development.
Borges and her team have been studying the scents that emanate from the syconium, which play a vital role in attracting the fig wasps.
After pollination, there are several species of non-pollinating wasps which deposit their eggs before the figs harden. These wasps act as parasites to either the fig or possibly the pollinating wasps. As the fig develops, the wasp eggs hatch and develop into larvae. The males of many species lack wings and are unable to survive outside the fig for a sustained period of time.
After mating, a male wasp begins to dig out of the fig, creating a tunnel through which the females escape. Once out of the fig, the male wasps quickly die. The females find their way out, picking up pollen as they do. They then fly to another tree of the same species, where they deposit their eggs and allow the cycle to begin again. Reproductive coevolution in Ficus The fig—wasp mutualism originated between 70 and 90 million years ago as the product of a unique evolutionary event. Host switching and pollinator host sharing may contribute to the incredible diversity of figs.