Abstract:

Aims The interaction between Ficus species and their pollinating wasps (Agaonidae) is a striking example of a mutualism. Figs are also exploited by chalcidoid wasps that develop within the figs but do not transfer pollen. F. racemosa, a common species in the Xishuangbanna tropical area, is monoecious, and there are five species of non-pollinating fig wasps that coexist with the fig-pollinating Ceratosolen fusciceps inside the syconium. These non-pollinating fig wasps oviposit from outside the fig wall using long ovipositors to reach the ovules inside during different phases of syconium development. We studied the effect of the non-pollinating wasps on mutualism, in order to determine the relationship between the time and the distribution of female flowers, and to understand how non-pollinating species coexist with the mutualistic species.

Methods We isolated syconia at different phases, using bags in order to prevent non-pollinating wasps from ovipositing on the fig wall. We brought the syconia into the laboratory when the figs were mature and let the pollinating and non-pollinating fig wasps leave the syconia in the isolation bags. We then counted the number of seeds and pollinating fig wasps and compared differences in numbers with independent-samples t-test.

Important findings During the prefemale phase, before the pollinating fig wasp enters the fig cavity, Platyneura testace, Apocrypta sp. and P. mayri oviposit on the fig wall. These non-pollinators significantly affect the mutualism, especially the product of the pollinating fig wasp. During the interfloral phase, when the pollinating fig wasp has entered the fig cavity, P. mayri, A. westwoodi and P. agraensis oviposit on the fig wall. Although these non-pollinators reduce the number of seeds and fig-pollinating wasps, they do not significantly affect the fig-wasp mutualism. P. mayri is a gallmaker that oviposits during prefemale and interfloral phases. It affects the reproduction of fig-pollinating wasps during prefemale phase, but mainly affects seed production during the interfloral phase. Apocrypta sp. and A. westwoodi do not parasitize C. fusciceps but P. testacea and P. mayri. So the number of pollinating wasps and non-pollinating wasps remains balanced, and this is favorable for stability of the fig-pollinating wasp mutualism.

Key words: Ceratosolen fusciceps, pollinating fig wasp, non-pollinating fig wasps, fig and fig wasp mutualism