2026/04/19 by Manuela Giovanetti, Laura Zavatta, Simone Flaminio +6 · 2 voices
Agricultural and Biological Sciences · Environmental Science · #Ecology and Vegetation Dynamics Studies #Plant and animal studies #Plant and fungal interactions
paper · doi:10.26786/1920-7603(2026)880
openalex publication_date 2026/04/19 · openalex created_date 2026/04/20 · openalex updated_date 2026/06/20
Field margins support wild bees by providing richer floral resources than most crops. While transect-based hand netting offers insight into bee–plant interactions, it underrepresents the full range of each bee’s foraging activity. To uncover more of each bee's foraging behaviour, we complemented transect data with palynological analysis of pollen loads from captured bees. In 2021 and 2022, we collected 58 Andrena and 176 Lasioglossum females plus males during transect surveys. Sixty-six plant species were identified along the transects, at least to genus level. All bee specimens were identified to species level by a taxonomist, and their pollen loads (pollen carried on the body in various positions) analysed in the lab. The 19 Andrena species were mostly active in spring, showing a succession of species, whereas the 18 Lasioglossum species were more common in summer, with some overlap. Field observations showed Crepis species were the most frequently visited, with 52.7% of Andrena and 58.2% of Lasioglossum collected on them. Cichorium intybus was also a common resource for Lasioglossum (17.6%). Pollen analysis identified 63 taxa (40% overlapping with transect data) substantially expanding the list of visited plant species. Our findings highlight the crucial role of palynological analyses in revealing bee foraging preferences, even pointing to an underappreciated role of trees, and the importance of considering also male individuals. Yet, some observations on transects revealed unexpected food sources. For better understanding of lesser-known Apoidea species, we recommend incorporating planned pollen analyses into transect monitoring. Both bee and pollen identification require specialised expertise, but this integrated approach provides vital insights into plant-pollinator dynamics.