Researcher Ko Mochizuki from the University of Tokyo found that two species in the genus Angelica are primarily pollinated by hornets, overturning the belief that Angelica species are generalists with a variety of pollinators. This discovery has significant implications for future ecological research and conservation efforts. The findings were published in the journal Ecology, shedding light on the unique pollination mechanism of these plants.
Many plants in the carrot family Apiaceae are considered generalists, attracting a wide variety of insects with their white, small, open flowers that secrete nectar and produce pollen. However, Angelica decursiva and Angelica hakonensis, two species in the genus Angelica, do not fit this description. Mochizuki observed hornets feeding on the nectar of these two species, prompting further investigation into their primary pollinators and challenging the conventional wisdom about pollination in the family Apiaceae.
To confirm that hornets were indeed the primary pollinators of these species, Mochizuki conducted a series of experiments. He quantified the numbers and types of visitors to the flowers, checked the amount of pollen stuck to the bodies of captured visitors, and performed an experiment blocking hornets and other insects from accessing the flowers. The results consistently showed that hornets were the most numerous visitors to the flowers, indicating their role as the primary pollinators of Angelica decursiva and Angelica hakonensis.
Excluding hornets from the flowers actually resulted in higher seed production, suggesting that other visitors were able to gather on the flowers in their absence. Mochizuki also observed hornets hunting and killing other insect visitors on the inflorescences, highlighting the aggressive nature of these pollinators. This incremental step in understanding the pollination of these plant species has broader implications for future research and conservation efforts.
Despite being considered pests in their native range and invasive species in areas like North America, hornets play a crucial role as pollinators for certain plant species. This study underscores the importance of hornets in pollination, opening up new avenues for research and conservation. By studying the unique pollination mechanisms of Angelica decursiva and Angelica hakonensis, researchers can gain insights into the intricate relationships between plants and their pollinators, contributing to our understanding of ecosystem dynamics.
The discovery that hornets are the primary pollinators of these two Angelica species challenges traditional assumptions about pollination in the family Apiaceae, highlighting the complexity and diversity of plant-insect interactions. This research paves the way for further studies on the role of hornets in plant pollination and the implications for conservation efforts. By recognizing the importance of hornets as pollinators, researchers can better appreciate the intricate web of relationships that sustain biodiversity and ecosystem health.
