Spatial heterogeneity and host repression in fig-fig wasp mutualism

作     者：WANG RuiWu WEN XiaoLan CHEN Chun SHI Lei COMPTON Stephen G. 

作者机构：State Key Laboratory of Genetic Resources and Evolution Kunming Institute of Zoology Chinese Academy of Sciences Statistics and Mathematics College Yunnan University of Finance and Economics Department of Zoology and Entomology Rhodes University School of Biology University of Leeds 

出 版 物：《Science China(Life Sciences)》 (中国科学（生命科学英文版）)

年 卷 期：2015年第58卷第5期

页      面：492-500页

核心收录：

学科分类：090504[农学-特种经济动物饲养（含：蚕、蜂等）] 0907[农学-林学] 08[工学] 0905[农学-畜牧学] 0829[工学-林业工程] 09[农学] 

基　　金：supported by the National Natural Science Foundation of China (31170408, 31270433, 31370408) the National Science Fund for Distinguished Young Scholars (31325005) NSFC-Yunnan United Fund (U1302267) the West Light Foundation of the Chinese Academy of Sciences 

主　　题：Agaonidae cooperation conflict co-evolution repression mutualism density dependence 

摘      要：It is generally believed that physical heterogeneity in common resource or evolutionary restraint can sufficiently prevent direct conflict between host and symbionts in mutualism systems. Our data on fig/fig wasp reciprocal mutualism(Ficus racemosa), however, show that structural barriers of female flowers or genetic constraints of pollinators previously hypothesized exist, but cannot sufficiently maintain the mutualism stability. The results show that a positive relationship between seed and wasp production could be maintained in warm season, which might be because of density dependence restraint among foundresses and their low oviposition and pollination efficiency, keeping common resource(female flowers) utilization unsaturated. Whilst, a negative correlation between wasp offspring and viable seed production was also observed in cold season, which might be that the increased oviposition and pollination efficiency maximized the common resource utilization. The fitness trade-off between fig and pollinator wasps is greatly affected by environmental or ecological variations. The local stability might result from temporal low exploitation efficiency of pollinators together with interference competition among pollinators. We suggest that host repression through the active regulation of bract closure, which can create interference competition among the foundresses and prevent extra more foundresses sequential entry in fruit cavities, would help the figs avoiding the cost of over-exploitation. This essentially takes the same role as sanctioning of cheating or competitive behaviors.