Asymmetric sharing of pollinator fig wasps between two sympatric dioecious fig trees: a reflection of supply and demand or differences in the size of their figs?

作者：Hui Yu, Zhiwei Zhang, Lu Liu, Yufen Cheng, Xiaoxia Deng, Simon T. Segar, Stephen G. Compton · 发表于：Botanical studies · 年份：2022 · DOI：10.1186/s40529-022-00338-9 · 被引用次数：16 · 研究领域：Plant and animal studies、Plant Reproductive Biology、Phytochemistry and biological activities of Ficus species

BACKGROUND: Host specificity among pollinator fig wasps (Agaonidae) depends on host plant specific volatile cues, but fig wasps must also pass through a narrow physical barrier (the ostiole) if they are to pollinate and oviposit. Across South East Asia the dioecious shrub Ficus hirta is associated with at least ten pollinator species allied to Valisia javana. Ficus triloba has a single recorded pollinator, Valisia esquirolianae. Receptive figs of F. hirta are usually much smaller than those of F. triloba, but at a mainland site where F. hirta has atypically large figs we identified both V. esquirolianae and V. javana from both Ficus species using COI and ITS2 sequencing. To investigate whether this host overlap was exceptional we reared fig wasps from the two trees elsewhere and recorded features that may facilitate host transfer between them, including attractant volatiles, reproductive phenology and the sizes of their figs and fig wasps. RESULTS: The two Ficus species were found to support both Valisia species at several of the sites, suggesting that the differences we detected in volatile profiles, ostiole sizes and pollinator head sizes are not strict barriers to host sharing. Valisia javana colonised F. triloba more frequently than V. esquirolianae colonised F. hirta. CONCLUSIONS: This asymmetric sharing of pollinators may reflect the relative abundance of the two species of fig wasps and differences in host reproductive phenology. Asynchronous flowering of individual F....