What the Fig....

What the fig is that ??? 

Its a geocarpic fig actually, meaning that the figs are actually produced at ground level to benefit animal dispersal.  This particular species is Ficus uncinata which we found in central Kalimantan lowland forest close to a stream.

Figs emerge from  long hairy stolons that dangle down a branch and slide below the leaf litter. The seed dispersers are pigs, deers and mouse deers, which are not deers actually but more related to pigs. The spiky hooks on the pericarp is decorative but their real  purpose is to discourage ingestion by ground birds like pheasants and jungle fowl which have powerful gizzard that destroy the seeds

 

* cartoon from D. Eisikowitch and M. Ghara Acta horticulturae October 2017

 Now abit of biology.

Figs may be monoecious (where male and female flowers appear inside the same fig) or dioecious, where  different trees bear either all-male or all-female figs.  Ficus uncinata belongs to the latter category, which can be represented by either c (male) or d (female) figs. As you can see from the cartoon, the male fig actually contains many female short styled flowers, which are sacrificial in function and will not develop  seeds (as opposed to only long style ones in the female fig). The female pollinator, which is a species specific pollinator wasp, enter from a pore called ostiole and attempt to insert its long ovipositer via the style into the ovary to release the eggs but only succeed to do so in the short-style flowers in male fig,  the style in the female figs being too long for the ovipositer to reach the ovary. The eggs hatch in the male fig and induced gall formation which nourish the larvae - while the female figs, once pollinated, develop seeds and not galls. Hence, the fig offered its short styled female flowers as food for the wasp in exchanged for the long style flowers to be pollinated .... both the fig and wasp goes home happy.

This particular tree is a male as evidenced by the long stamens (white strands at top left) and the galls inside. 

Against the trend in the competitive, selfish natural world, the fig and the pollinator wasp work in such perfect mutualism  that it seems inevitable that there has to be a hacker, a lock picking free loader to spoil the fun. This comes in the form of a parasitic wasp, which the way, is really cool....

 .... this is another type of fig which we saw in Indochina. Can you see the tiny parasitic wasp at the top left fig ?

This wasp does not pollinate the fig - in fact it preys on the larvae of the pollinator wasp resulting in lower seed yield. Here you can see it inserting its skinny ovipositor through the pericarp

If you try pushing a strand of hair through the unripe fig, you will find that it will be an exercise in futility. However, this ovipositor is no ordinary strand of hair - its a material scientist's dream - not only does it has chemical and mechanical sensors, its ultra sharp tip is reinforced with zinc and throughout its length tiny pits are strategically located to allow it to bend rather then snap and break. This appendage allows this wasp to punch and feel its way into the area of the fig where the larvae of the pollinator wasp reside where it will deposit its eggs and gate crash the perfect party.

They are so cool that they can be forgiven for being the bad guys in this overall scheme of things ....