DATE2026.10.19 #Press Releases
The Possibility of Seed-Consuming Pollination Symbiosis—a First Among Sawflies
Disclaimer: machine translated by DeepL which may contain errors.
—Regional Diversity of Japan’s Endemic Cat’s-eye Plants and Long-Mouthed Sawflies—
Summary
A research group led by Marika Yamaguchi (Ph.D. candidate) of the Graduate School of Science at The University of Tokyo and Senior Researcher Yudai Okuyama of the Department of Plant Sciences at the National Museum of Nature and Science has revealed the existence of a previously unknown, unique pollination symbiosis between plants of the Iwabotan series of the genus *Iwabotan* (Saxifragaceae)—a group of plants endemic to Japan—and insects of the genus *Kuchinaga-habachi*(Chalcididae), a genus of wasps endemic to Japan.
Field surveys and specimen analyses conducted across Japan revealed that while adult Kuchinagahachi and Hida-Kuchinagahachi wasps act as the primary pollinators of the Iwabotan series by transporting pollen, their larvae feed on seeds and grow inside the fruits of these plants.Furthermore, it was confirmed that excluding pollinators significantly reduced the fruit-setting rate, and that adult visits to flowers enhance the plants’ reproductive success. Additionally, it was found that the proboscis length of both species within the genus Kuchinaga Habachi exhibits marked regional variation.
These findings are extremely intriguing as they provide clues to understanding the mechanisms by which the close interrelationships between plants and insects—which vary depending on regional conditions—influence each other’s evolution and diversification.Furthermore, the clarification of the ecological role of the genus *xml-ph-0000@deepl.internal*, whose function as pollinators was previously unknown, reaffirms the importance of considering interspecies interactions in the conservation of biodiversity.
Figure 1. Adult sawflies of the genus *Euura* transport pollen, while their larvae develop by feeding on seeds
Adults of *Euura* species, *E. kurokawana* and *E. hidaensis*, visit flowers of the *Iwatobon* species group (a), where pollen adheres to their bodies (b), thereby acting as pollinators. Adults also mate and lay eggs on the same plants (c, d). The larvae develop inside the fruits of these plants, feeding on the seeds (e).
Journals
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Journal name Plants, People, PlanetTitle of paper