Fine-scale relationships between pollinatiors and flowers revealed by using a high-speed camera

Background/Question/Methods

Most estimations of the pollination efficiency of insects have been based on observation by the naked human eye. However, some insect behaviors are too rapid to be sufficiently analyzed using traditional video cameras alone. Traditionally, when we compared efficiencies of multiple pollinators in one plant species, deposit pollen grains on stigmas and remove pollen grains from anthers have been demonstrated. Nonetheless, some studies have shown the numbers of deposited and removed pollen grains varied among flower-visits. These mechanics of these transfers can now be quantified with the use of high-speed video. Here we demonstrate the use of high-speed cameras to analyze the fine-scale behaviors of Macroglossum pyrrhosticta, Xylocopa appendiculata, and Papilio dehaanii when visiting Clerodendrum trichotomum.

Results/Conclusions

The number of contacts with anthers and/or stigmas, and frequencies of body part contact with anthers and/or stigmas differed significantly among pollinator species. Especially, M. pyrrhosticta made the least number of contacts with anthers and/or stigmas even though it showed the highest visitation frequency. On the other hand, although the number of grains deposited on stigmas did not vary significantly with the number of times pollinators contacted stigmas, there were significantly difference in the number of pollen grains deposited per a visit among pollinators. In contrast, pollen removal from the anthers increased significantly with the number of contacts to anthers without significantly difference in the relationship. Pollen removal varied among the three types of pollinators. In addition, the three types carried pollen on different parts of their bodies. In M pyrrhosticta and X. appendiculata, a large number of contacted body part with anthers differed significantly from the body part that attached a large number of pollen grains. These results demonstrated that pollination dynamics differ among pollinator species, and flower visits and pollination rates are not equal.