A fruiting Ficus cucurbitina with the figs at receptive stage.
The red marking around the ostiole is a visual signal to fig wasps that this fig is receptive and waiting to be pollinated. Receptive figs also normally emit scents (olfactory clues) to attract fig wasps carrying pollen.
Thanks to Suzana Sabran of the SAN herbarium and the DFO staff at Deramakot for information and photographs.
Stages in the Reproduction of Monoecious figs
Of the c. 150 species of Bornean figs c. one third are monoecious (both male and female flowers in the same fig) and two thirds are dioecious.
Dioecious figs grow as separate male and female trees. Male figs act as brood chambers for pollinating fig wasps. Only female figs produce seeds.
In contrast Monoecious figs produce both fig wasps and seeds from the same fig. All stranglers in Section Conosycea such as F. cucurbitina are monoecious.
Stage 01: Calyptrate bud covers fall off the young growing fig allowing adult female fig wasps to enter the now receptive fig through the now open ostiole.
Stage 02: The arriving female fig wasps have already mated inside their birth fig and are carrying both fertile eggs and male pollen from their birth fig into the receptive fig.
Stage 03: The female fig wasps lay their fertile eggs inside the gall flowers and pollinate the female flowers inside the receptive fig. They then die inside the fig.
Stage 04. The receptive fig now becomes a birth fig in this cycle of life.
The eggs develop into fig wasps which hatch simultaneously. Male and female fig wasps mate inside the fig and exit the fig through the open ostiole. The male fig wasps have no wings and gather on the surface of the fig to act as decoys for predators. This allows winged female fig wasps to escape predators and fly off to find another receptive fig at just the right stage of ripeness (Stage 01)
Stage 05. Once the wasps have left -the fig starts to ripen. The pollinated female flowers produce seeds. The fig changes colour from green to red and the latex dries up. The fig is now ripe and ready to be eaten by dispersers such as hornbills, civets and orangutans which will swallow and disperse the seeds via defecation.