A researcher describes species of fig tree parasites which compete and even prey upon the fig wasps during the many phases of the. Fig trees and fig wasps are partners in life, but sometimes the trees betray their closest allies. These fig wasps are the sole pollinators of fig trees and in turn, fig wasps can breed nowhere else but inside figs, a relationship that is a classic example of an .
Their pollinating wasps belong to the family Agaonidaewhich contains 20 genera. The mother wasp now has only 24 hours to live About half of figs are "monoecious", meaning each tree produces both male and female flowers. The others are "dioecious" and have two kinds of figs on separate plants: Fig trees produce their flowers within enclosed green spherical structures called syconia.
Each syconium contains hundreds or even thousands of flowers. In monoecious species, the female flowers mature first, signalling the syconium to release a fragrant scent.
Enticed by the odour, a pregnant female wasp enters the syconium through a tiny opening in the centre.
What Is the Symbiotic Relationship between Fig Wasps & Figs?
The wasp is carrying pollen from the flower where she was born. Once inside the syconium, she deposits the pollen, fertilising the flowers. Their purpose completed, the wingless male wasps die Then she lays her eggs in the female flowers, using long tubes called ovipositors. The mother wasp now has only 24 hours to live. Before she dies, like any good mother, she ensures the survival of her babies.
She injects the flowers with a chemical that transforms them into fat, rounded structures called galls. When the eggs hatch, these galls will provide food and shelter for the young offspring. They are fig wasp nurseries. The young wasps will grow to adulthood, and even mate with each other, within the syconium.
Then the males and females face very different fates. View image of A male Waterstoniella masii emerging from Ficus stupenda Credit: They bite through the syconium, creating an opening for the winged females to fly out.
Their purpose completed, the wingless male wasps die, and the syconium ripens into mature, fruit-containing seeds. Meanwhile the female wasps collect pollen from the male flowers, which have just matured. They stuff the pollen into specialised pollen pockets, located above the abdomen. The nature of dioecious fig trees creates an evolutionary conflict, one that the fig wasps seem to be losing They then leave in search of another fig syconium.
It lays its eggs and dies.
Synchronized actions Once inside the fig, the female wasp lays eggs in many of the flowers but not all. At the same time, it fertilizes the flowers with pollen stored in a pouch on the underside of its thorax.
The flowers on which the eggs are laid now undergo a transformation to become hardened structures call galls. Now begins the C phase, which lasts two to three months. The flowers that receive pollen but no eggs develop into seeds.
Flowers that receive eggs and harden into galls become nurseries with food and shelter for wasp larvae.
New phase proposed in the relationship between figs and wasps | AGÊNCIA FAPESP
The D phase occurs at the end of larval incubation. This is also when the male flowers start to mature, opening up to expose pollen containers known as anthers.
The male penetrates the female with a telescopic penis and fertilizes the female inside the gall. Once they have mated in this way, the males use their mandibles to bite through the fig wall. They then go out through the hole, fall to the ground and die. Leaving the receptacle through the hole made by their brothers, the fertilized females fly away in search of other fig trees, and the cycle begins again.
The E phase consists of seed dispersal.
The figs are eaten by monkeys, rodents, bats, peccaries and many other animals. Almost all forest-dwelling vertebrates feed on figs as part of their diet. F phase Palmieri has now proposed a new phase in addition to the five phases of the classic fig-wasp lifecycle, which has been studied for 50 years.
They manage to insert their eggs into figs without performing the biological role of pollination.
- A tale of loyalty and betrayal, starring figs and wasps
- New phase proposed in the relationship between figs and wasps | AGÊNCIA FAPESP
- New phase proposed in the relationship between figs and wasps
These figs were discarded and left out of the research. In some cases, larvae that were almost the same size as the fig had eaten almost its entire contents. In the article just published, I describe insects belonging to five orders and 24 different families that are not fig wasps but that also interact with figs, performing different functions.
Some rely on fallen figs to complete their development.
All the insects identified have representatives in both categories except for ten wasp species belonging to three families that are not fig wasps but that bear some resemblance to them. All ten are early fig interlopers that oviposit in figs and the larvae of which compete directly with those of fig wasps for food and space inside the fig or simply feed on them, leaving the fig when they reach adulthood.
In the article, Palmieri describes the modus operandi of several early fig interlopers in detail. One is Lissocephala, a genus of flies that lay eggs in the ostiole at the same time as the original female wasp is entering the fig. The fly larvae migrate to the interior of the fig and feed exclusively on yeast and bacteria brought inside by the pollinating wasp.
The flowers produce seeds internally after being pollinated by fig wasps. The mutualism is ancient, Palmieri explained. The oldest fossils of fig wasps date from 34 million years ago.
BBC - Earth - A tale of loyalty and betrayal, starring figs and wasps
They closely resembled the species alive today, indicating that the symbiotic relationship evolved early and has not changed fundamentally since then.
Molecular evidence shows that the relationship existed 65 million years ago, suggesting that it might be even older, perhaps going back to the age of dinosaurs. We believe these inflorescences were still open, so they could be pollinated by various insects," Palmieri said.
Over the course of at least 65 million years of evolution, the fig's inflorescence became an enclosure sealed off from the outside world, and only the fig wasp was able to penetrate it.
The fig-wasp lifecycle begins when the female wasp enters the fig. The flowers open inside it, so they need a special pollination process. They cannot rely on wind or bees to carry their pollen. That's where the fig wasp comes in," he explained. The five phases of the cycle Inside the fig, there are female and male flowers that develop at different times. The A phase occurs when the female flowers are not yet mature. They soon mature and are ready to be fertilized. They become receptive to the wasps and release a scent made up of a huge amount of volatile compounds, triggering the B phase.
Each fig receptacle is not entirely closed, but has a small hole called an ostiole, through which the female wasp penetrates its interior. As it does so, it loses its wings and its antennae are broken, so that it cannot get out again. It lays its eggs and dies. The lifecycles of figs and fig wasps are studied as a way of understanding the evolution of mutualism. Coelho Once inside the fig, the female wasp lays eggs in many of the flowers but not all.
At the same time, it fertilizes the flowers with pollen stored in a pouch on the underside of its thorax.