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Modern fossil discoveries have revealed that figs are among the first cultivated crops. an ancient, complex and symbiotic relationship with a tiny fig wasp. Place on parchment paper-lined baking sheet; roast cut side up at. We humans also engage in mutualism with other species—we shelter But in the fig tree-fig wasp relationship, the barter is not as simple as it seems. . transactions—credits and debits—the fig tree keeps a balance sheet for. This is a case of commensalism: one organism benefits while the the strangler figs cannot possibly live without the fig wasps, and vice versa.
How this timing is managed, especially given that different fig trees flower at different times Thomson et al,has not been explained by any source that I have found. The female wasps get covered with pollen from the male flowers before digging their way out of the synconium, and flying off in search of other fig trees.
When a female wasp finds a synconium on another tree, she burrows in and lays her eggs, then dies. In the process, the pollen she has carried with her is brushed off onto female fig flowers, which are thus pollinated Kricher How the wasp locates a synconium in the right stage of development, with mature female flowers, is another question that my research has not answered.
She certainly cannot try multiple flowers; the female wasp is often injured by the process of burrowing into the synconium Kricher The females only live for about a day outside the synconiums Kricher Yet a genetic analysis study of fig paternity ie, which trees donated pollen for which fruits has shown that the wasps, despite their extremely short lives, are "efficient agents of long-distance dispersal, routinely moving up to 10 km between flowering trees" Nason et al, !
Implications for Conservation Numerous studies have been done regarding various aspects of strangler fig ecology. Some have focused on the conditions for strangler fig seed germination: Putz and Holbrook showed that humus from decaying leaves available to epiphytic figs in palm tree canopies was higher in nitrogen, magnesium, and potassium than soil on the ground, suggesting that nutient levels may be a factor in the germination and growth of figs, and possibly other epiphytes as well.
Swagel et al demonstrated that Ficus aurea seeds require high substrate water levels for germination, and suggested this as another reason that stranglers typically germinate only in the canopy, and, in drier areas, mostly on palm trees.
Other studies have focused on factors affecting genetic diversity among seemingly small populations of strangler fig trees.
What Is the Symbiotic Relationship between Fig Wasps & Figs? | Animals - relax-sakura.info
Thomson et al examined cases of allofusion fusion of multiple individuals into one tree, as discussed above and found that while the trees produced flowers of multiple genotypes, all of the flowers in a given "mosaic" tree flowered in synchrony, preventing those separate genotypes from pollinating eachother since the male and female flowers do not mature at the same time on a given tree.
This means that the gene pool may be larger than the number of trees since there can be multiple genotypes per treebut a certain population size of whole trees is still needed to meet pollination requirements and sustain wasp populations. Nason and Hamrick asserted that the wide dispersal range of fig wasps allows strangler figs to be pollinated even in otherwise isolated forest fragments. Moreover, conservation of strangler figs, and by implication all of the species that the figs support, "may be dependent on the preservation of forest elements in a surrounding fragmented landscape.
Laman, Timothy G Allen; Hamrick, James L 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. In their latest research, the team found that certain type of fig trees have evolved a different strategy—one that tilts the balance of the relationship in their favour. These fig trees are dioecious—the male and female flowers are present separately on different trees, unlike the monoecious trees where both male and female flowers are present in the same tree.
In these species, wasps develop in male flowers but cannot develop in female flowers as they have long stalks inside, so the female wasp cannot reach into the ovaries to lay eggs and gall the flowers.
What Is the Symbiotic Relationship between Fig Wasps & Figs?
Borges and her team found that in these fig trees, when the male and female trees flower synchronously, the female figs deceptively attract wasps by mimicking the scent of the male flowers. The female wasps are tricked into entering the synocium, but they cannot lay eggs and end up dying in vain. The female flower, however, is pollinated and goes on to produce seeds. The fig tree is commonly found in tropical and sub-tropical forests.
At any given time, fig trees are always producing fruit, and sometimes are the only fruit available to animals and birds.
The fig is a keystone species—it plays a unique and crucial role in maintaining biodiversity and population density. That's when we decided to investigate what was going on," Palmieri said. 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.
These insects may colonize figs during different phases of the tree's lifecycle. Some rely on fallen figs to complete their development. Palmieri divided the insects into two categories according to their role in the fig tree's ecology and their potential impact on its reproduction.
He called the categories "early fig interlopers" and "fallen fig fauna.
The fly larvae migrate to the interior of the fig and feed exclusively on yeast and bacteria brought inside by the pollinating wasp. The flies finish their development inside the fig and leave by the exit hole previously chewed in the fig wall by male wasps. Butterflies and moths are the most aggressive group of insects in terms of the damage to figs. They lay eggs in the fig wall. In the C phase, their larvae bore through the fig wall and feed indiscriminately on fig pulp, wasps and seeds.
The larvae destroy the hanging fig and crawl out to pupate in cocoons attached to branches of the tree. In the case of fallen fig fauna, explained the FAPESP-funded researcher, the category comprises various organisms that feed on the fleshy parts or seeds of ripe figs not consumed by fruit-eating vertebrates. They take advantage of the window of opportunity created by the figs that fall under the parent tree in the F phase.
Fallen fig fauna consists mainly of beetles that feed on fruit remains. Beetles take advantage of the fig development cycle in various ways. Some colonize figs on the tree in the early C phase.
New phase proposed in the relationship between figs and wasps
Their larvae grow inside the figs and stay there when the ripe fruit falls to the ground. They then migrate to the soil, where they dig holes and pupate in cocoons. In addition to the evolutionary implications of pollination mutualism, an additional factor relating to the success of the odd fig species is probably the highly diversified fauna of insects associated with fig treessuch as nonpollinating wasp species.
Pressure from these parasitic wasps will have been, and continues to be, a key driver of fig species diversification," Palmieri said.