the wasp and the fig

Sometimes small things are more exciting then big things. The other day in Ruaha we were having breakfast at w7 under the sycamore figs; a great chance to talk about the tiny fig wasp that pollinates this majestic tree laying eggs inside the fruit. Actually the fig is not only a fruit, is a fruit and a flower together, it is called syconium. In Chinese in fact, the fig is called "wú huā guǒ" that means the fruit without flower, the name is beautiful but not appropriate. The flower exists, its just not visible, it is inside the "fruit".

The relation between the fig and the wasp is an incredible symbiosis, each fig has his specie-specific wasp that pollinates it, so they are totally dependant on each other. The pregnant wasp enters the ostiole, a tiny hole that is open when the fruit is not ripe yet, the aperture is tiny and in the process the wasp often breaks antennas and wings, when inside she lays the eggs with her ovopositor in the ovary of the female flower, then she slowly dies eaten by nematod worms.

Meanwhile the ostiole closes and the insects start to develop from the eggs, the males reach adult stage first. They are tiny animals with big mandibles and no wings. First they mate with the females, often before they emerge to complete adulthood, then they bite through the fig all the way to the outer world, this allows new oxygen to come in.

With this final stage the male flowers ripens, the female wasps, already pregnant, walk over it on their way out transporting the pollen with them. As soon as they get out of the syconium they fly off to the next fig tree where everything starts again. The wasps full of pollen reach in fact another fruit and entering to lay eggs, pollinate the tree.

By the side of the specific wasps there is a number of parasitic wasp species that lay eggs from the outside with a long ovopositor that pierces the fruit. The down side of this behaviour is that if the specific wasp is not in the fig, there is no male to open the way for the parasitic wasps, whose males are not able to do so. I looked for the right fig, cut it open to show the guests better what I was explaining. To my pure joy a cloud of new born wasps started flying off. Hundreds of them, the fig wasps with the short ovopositor, the parasitic wasps with longer ovopositor, metallic green, pale yellow, iridescent black, different species with different colours and characteristics. They started climbing all over our fingers and there stretch the wings and unfold them getting ready to fly... it was a stunning show. Such a blessing and such a great detail to end a safari with.

Direct postPietro LuraschiAugust 5, 2015