Ficus hispida L. (Moraceae) is a remarkable species in the ecosystem of tropical rainforests in Xishuangbanna, China. The figs and fig_pollination wasps (Chalcidoidae: Agaonidae) are highly co_evolved mutualists tha...Ficus hispida L. (Moraceae) is a remarkable species in the ecosystem of tropical rainforests in Xishuangbanna, China. The figs and fig_pollination wasps (Chalcidoidae: Agaonidae) are highly co_evolved mutualists that depend completely on each other for propagating descendants. Pollination of all fig species is done by fig wasps; their unique symbiotic associates, the fig wasps, cannot develop in anywhere except in the fig syconia. The present paper reports on the biology and flowering phenology of F. hispida , as well as the propagation character and pollination behavior of the fig wasps (Ceratosolen solmsi marchali Mayr) based on our observations in the rainforests of Xishuangbanna, southern Yunnan of China. F. hispida is a dioecious tree that annually blossoms and bears fruits 6-8 times, with four to five fruit_bearing peaks. The male trees produce pollen and provide fig wasps with reproductive havens, while the female trees produce fig seeds after pollination by the female wasps. Pollen of F. hispida cannot escape from the dehiscent anthers until they are disturbed by fig wasps. The female wasps open the anthers and collect pollen with their antennal scrapes, mandibles and legs, and then carry pollen to the female receptive syconia where fertilization takes place. Meanwhile, some of the female wasps lay eggs in the male receptive syconia. It takes about 3-67 min to search for the receptive syconia for pollination, and 15-23 h to enter the female receptive syconia. The number of female wasps entering a syconium has close relation with the impregnation and seed_bearing rate of female flowers, as well as the oviposition and reproduction rate of the fig wasps themselves. F. hispida is endowed with a relatively high level of seed bearing (54.1%-82.5%, average 73.8 %). The wasp oviposition rate on the male flowers is between 72.3% and 93.8% with a mean of 84.4%.展开更多
Aims Nitrogen(N)and phosphorus(P)are limiting nutrients to life across a variety of ecosystems.N:P stoichiometry,concerning the balance of these two elements,has recently received great attention.However,little is kno...Aims Nitrogen(N)and phosphorus(P)are limiting nutrients to life across a variety of ecosystems.N:P stoichiometry,concerning the balance of these two elements,has recently received great attention.However,little is known about the nature of N:P stoichiometry in obligate mutualism.Methods N:P stoichiometry of Ficus racemosa and its pollinating wasp Ceratosolen fusciceps,an example of coevolving obligate mutualism,was investigated,and the N:P stoichiometric traits of male versus female wasps were compared.Important Findings Nutrient concentrations in C.fusciceps were much higher than in its host.N enrichment in fig wasp was evidently stronger than phosphorus.N concentrations of male fig wasps were significantly higher than those of females,while P concentrations of female fig wasps were remarkably higher than those ofmale ones.Therefore,N:P ratios inmale fig wasps were significantly greater than in female fig wasps.N:P ratio in fig-pollinating wasp displayed linear functions to fig N contents,suggesting that N limitation in fig wasps may dominate the nutritional relationship between fig pollinator and its host.Fig wasp population size had significant influences on N concentrations in host fig and female wasp per se.Driven by the nutritional stress of pollinating and parasite insects,fig fruit preferred increasing its diameter first but not nutrient richness.Values forNand P contents of fig pollinators showed seasonal differenceswith greater N:P ratios in dry season than in rainy season.The observations suggest that tropical climate change would result in more severe N limitation to fig-pollinating wasp and may further influence the stability of fig–fig wasp mutualism.展开更多
文摘Ficus hispida L. (Moraceae) is a remarkable species in the ecosystem of tropical rainforests in Xishuangbanna, China. The figs and fig_pollination wasps (Chalcidoidae: Agaonidae) are highly co_evolved mutualists that depend completely on each other for propagating descendants. Pollination of all fig species is done by fig wasps; their unique symbiotic associates, the fig wasps, cannot develop in anywhere except in the fig syconia. The present paper reports on the biology and flowering phenology of F. hispida , as well as the propagation character and pollination behavior of the fig wasps (Ceratosolen solmsi marchali Mayr) based on our observations in the rainforests of Xishuangbanna, southern Yunnan of China. F. hispida is a dioecious tree that annually blossoms and bears fruits 6-8 times, with four to five fruit_bearing peaks. The male trees produce pollen and provide fig wasps with reproductive havens, while the female trees produce fig seeds after pollination by the female wasps. Pollen of F. hispida cannot escape from the dehiscent anthers until they are disturbed by fig wasps. The female wasps open the anthers and collect pollen with their antennal scrapes, mandibles and legs, and then carry pollen to the female receptive syconia where fertilization takes place. Meanwhile, some of the female wasps lay eggs in the male receptive syconia. It takes about 3-67 min to search for the receptive syconia for pollination, and 15-23 h to enter the female receptive syconia. The number of female wasps entering a syconium has close relation with the impregnation and seed_bearing rate of female flowers, as well as the oviposition and reproduction rate of the fig wasps themselves. F. hispida is endowed with a relatively high level of seed bearing (54.1%-82.5%, average 73.8 %). The wasp oviposition rate on the male flowers is between 72.3% and 93.8% with a mean of 84.4%.
基金State Key Basic Research Development Program(973 Program)(2007CB106801)National Natural Science Foundation of China(30830026).
文摘Aims Nitrogen(N)and phosphorus(P)are limiting nutrients to life across a variety of ecosystems.N:P stoichiometry,concerning the balance of these two elements,has recently received great attention.However,little is known about the nature of N:P stoichiometry in obligate mutualism.Methods N:P stoichiometry of Ficus racemosa and its pollinating wasp Ceratosolen fusciceps,an example of coevolving obligate mutualism,was investigated,and the N:P stoichiometric traits of male versus female wasps were compared.Important Findings Nutrient concentrations in C.fusciceps were much higher than in its host.N enrichment in fig wasp was evidently stronger than phosphorus.N concentrations of male fig wasps were significantly higher than those of females,while P concentrations of female fig wasps were remarkably higher than those ofmale ones.Therefore,N:P ratios inmale fig wasps were significantly greater than in female fig wasps.N:P ratio in fig-pollinating wasp displayed linear functions to fig N contents,suggesting that N limitation in fig wasps may dominate the nutritional relationship between fig pollinator and its host.Fig wasp population size had significant influences on N concentrations in host fig and female wasp per se.Driven by the nutritional stress of pollinating and parasite insects,fig fruit preferred increasing its diameter first but not nutrient richness.Values forNand P contents of fig pollinators showed seasonal differenceswith greater N:P ratios in dry season than in rainy season.The observations suggest that tropical climate change would result in more severe N limitation to fig-pollinating wasp and may further influence the stability of fig–fig wasp mutualism.
