Evolutionary background of parasitic pollinators in pollination mutualism by seed-eating insects

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K22666
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0703:Biology at organismal to population levels and anthropology, and related fields
• Research Institution: Kyoto University
• Principal Investigator: Furukawa Saori 京都大学, 生態学研究センター, 研究員 (10877319)
• Project Period (FY): 2020-09-11 – 2024-03-31
• Keywords: ハナホソガ属 / コミカンソウ科 / 絶対送粉共生系 / 虫こぶ / 相利共生

Outline of Final Research Achievements

Because of the ubiquity of the mutualisms between species, it has been thought that some mechanism is responsible for the stable maintenance of the mutualisms. However, there have been reports of mutualisms in which no such mechanism exists, suggesting that the mutualisms are maintained while dynamically changing, but this has not yet been verified. In this study, I hypothesized that seed-eating pollinators in a pollination mutualism system become parasitic pollinators by acquiring the ability to form insect gall, driving to extinction seed-eating mutualist of the same genus that share a host plant. The results suggest that (1) parasitic pollinators have expanded their distribution in recent years and (2) the evolutionary background of insect gall formation may be partly due to interactions with host plants as well as the influence of parasitic wasps.

Free Research Field

送粉生態学、進化生態学

Academic Significance and Societal Importance of the Research Achievements

本研究では、相利共生の利益とコストのバランスに関わる共生者の形質が変化した共生系に着目し、その進化背景の解明にアプローチした。従来の研究では、相利共生の安定性が「制裁」のみで説明されており、そうした共生者の形質は変化せず、一定に保たれると考えられてきた。それに対して、本研究の結果は様々な要因により相利共生の利益とコストに関わる形質は常に変化し続けているという、新たな見方の一つの根拠となる研究である。したがって、相利共生系は、「制裁」などの機構により定常状態に維持されているのではなく、様々な要因によりダイナミックに変化しながら維持されている、という新しい見方を提示する。