Reproductive behaviors facilitating stable coexistence betweenpollinating and non-pollinating fig wasps in Ficus semicordata

Author of the article:ZHANG Yuan1** LI Zong-Bo2*** ZHAI Shu-Wei3 YANG Da-Rong3

Author's Workplace：1. Yunnan Academy of Biodiversity, Southwest Forestry University, Kunming, 650224, China；2. Key Laboratory of Forest DisasterWaining and Control in Yunnan Province, College of Forestry, Southwest Forestry University, Kunming, 650224, China;3. Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming 650223, China

Key Words：Ficus, fig wasps, mutualism, ovipostion timing, species coexistence

Abstract：

     [Objectives]  The interaction between pollinating fig wasps (Agaonidae) and their host fig trees (Ficus) is a striking example of an obligate, pollination mutualism. The reproductive resources allocated for the stable coexistence of figs and fig wasps have attracted considerable research interest, but the reasons for the stable coexistence of pollinating, and non-pollinating, fig wasps remain poorly understood. [Methods]  Male trees of the dioecious fig species Ficus semicordata were observed in Xishuangbanna to determine the timing of oviposition by the pollinating fig wasp (Ceratosolen gravelyi) and 4 non-pollinating fig wasp species (Philotrypesis dunia, Apocrypta sp., Platyneura sp. and Sycoscapter trifemmensis). The community structure, spatial distribution of gall flowers, and gall volume, was also determined for the 5 fig wasps species. [Results]  The results show that the 5 fig wasp species had distinct oviposition intervals. The population size of pollinating fig wasps was significantly larger than that of all 4 non-pollinating fig wasp species combined. Offspring of the 5 wasp species developed in female flowers with different characteristics, such as different gall size and different pedicel length. Pollinating fig wasps tended to utilize flowers near the fig cavity and non-pollinating wasps were more likely to oviposit in flowers near fig wall. [Conclusion]  Although all 5 wasp species oviposit in Ficus semicordata syconia, the timing, and location, of oviposition differed among species. These differences may be the adaptions that facilitate the stable coexistence of different wasp species within the same host plant.