A team led by PhD student Idan Kahnonitch, supervised by Prof Yael Mandelik of the Hebrew University and Dr Asaf Sadeh of the Volcani Institute, has shown that the spread of viruses in wild bees is closely tied to the composition and availability of flowering plants, from individual sites to the wider landscape. Viruses long associated with managed honey bees were also found in wild solitary bees, with their distribution strongly influenced by local floral communities.
Published in Ecological Applications, the study surveyed wild bee populations across multiple sites in a Mediterranean agroecosystem. The researchers found that both the diversity of flowers at a site and the availability of floral resources in the surrounding landscape play a key role in determining where and when bee viruses occur.
Title image: A foraging Andrena bee in close contact with floral structures, particularly pollen grains that may harbour viruses. Credit: Gideon Pisanty.
Flowers as viral “meeting points”
Focusing on mining bees (Andrena species), an important group of wild pollinators, the team screened individuals for several common bee viruses. The results suggest that flowers act as shared meeting points for different pollinator species, creating opportunities for virus transmission. Certain floral communities were linked to a higher likelihood of virus presence, while the amount of floral resources within one kilometre of a site emerged as a particularly strong predictor.
“Our findings show that flowers are not just food sources for pollinators,” the researchers said. “They also shape disease dynamics within pollinator communities. This means that decisions about habitat management and restoration, which often concentrate on plant communities, can have unintended consequences for pollinator health if disease transmission is not taken into account.”
Links between wild and managed bees
The study also found evidence that viruses can be shared between managed honey bees and wild bees, underscoring concerns about how intensive agriculture and beekeeping may affect native pollinator health. Although virus levels in wild bees were generally low, their presence was consistently associated with ecological conditions, particularly floral composition and resource availability.
The researchers argue that pollinator conservation strategies need to go beyond simply increasing flower abundance or diversity. Instead, they call for a landscape‑level approach that considers which plant species are present, how pollinators share floral resources and how these interactions may influence disease spread.
This research was supported by the United States–Israel Binational Science Foundation and the Israel Science Foundation. The paper, “Virus distributions in wild bees are associated with floral communities at local to landscape scales”, is published in Ecological Applications and is available at: https://doi.org/10.1002/eap.70133.
Researchers:
Idan Kahnonitch, Katie F. Daughenbaugh, Na’ama Arkin, Tal Erez, Achik Dorchin, Michelle L. Flenniken, Nor Chejanovsky, Asaf Sadeh, Yael Mandelik
Institutions:
- Department of Entomology, Institute of Environmental Sciences, Faculty of Agriculture, Food, and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
- Department of Agroecology and Natural Resources, Newe Ya’ar Research Center, Agricultural Research Organization–Volcani Institute, Ramat Yishay, Israel
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, Montana, USA
- The Mina & Everard Goodman Faculty of Life Sciences, Bar Ilan University, Ramat Gan, Israel
- Department of Entomology and Nematology, Institute of Plant Protection, Agricultural Research Organization – Volcani Institute, Rishon Letzion, Israel
- The Steinhardt Museum of Natural History, Tel Aviv University, Tel Aviv, Israel