Abstract:

Ficus virens, a common ornamental species in Fuzhou, is a monoecious fig species. Ten Ficus virens trees were chosen in Fuzhou to study their pollination biology. The fruit development was synchronization within individual tree and asynchrony among trees. The syconium growth of F. virens was divided into five stages: pre-female phase, female phase, inter-floral phase, male-phase, post-floral phase. F. virens can continuously produce the figs year-round. There were two fruiting peaks in one year, respectively in January-February and June-July, and each tree could produce 1-3 crops annually. The growth time from pre-female phase to post-floral phase in the syconia varied in seasons. In winter and spring (December-May of the following year), figs grew slowly and lasted for nearly 130 days. In summer and autumn (June-November), figs grew faster, the inter-floral phase obviously reduced and the duration was about 80 days. The foundress number of F. virens during female phase was usually by only one wasp, so that the small and numerous syconia received wasps effectively, which significantly raised pollinate efficiency by wasps, and also ensured high ratio of fruiting in the syconia. There were seven kinds of wasps in syconia of F. virens, belonging to seven families (subfamily) of Chalcidoidea. Among them, Platyscapa coronata of Agaonidae was the only species-specific pollinator for F. virens, its pollinational manner was active pollination. Aprostocetus sp. parasitic in figs was discerned for the first time. The type and the amount of pollinators and non-pollinators in the syconia exhibited an obviously seasonal variation. Type and quantity of wasps in figs were more in winter and spring than in summer to autumn. Pollinator was the dominant species. The ratio of fruiting in figs was especially high. In summer and autumn, Camarothorax bismasculinus and Sycophila sp. were the dominant species, and the setting percentage of figs were extremely low, which had a negative effect on the reproductive interests of F. virens. The results would provide useful information for management of the city greening and protection of the tropical rainforest biodiversity.

Key words: reproductive characteristics, syconia, development, fig wasp