Manuela Giovanetti

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.

Stakeholder participation is increasingly promoted in ecological monitoring programmes, yet it raises critical questions about the spatial representativity and scientific robustness of resulting datasets. This study evaluates the representativeness of BeeNet, Italy’s national honeybee monitoring network (2019–2025), in depicting the agricultural landscape despite the non-randomised placement of selected apiaries. Apiaries were selected from voluntary beekeepers, balancing stakeholder participation with the objectives of the project. The distribution of over 300 workstations was assessed across Italian regions in relation to surface area and agricultural land-use composition, using Corine Land Cover (CLC) data aggregated into macro-categories. The analysis revealed that, although regional imbalances persist, particularly in mountainous areas or regions with challenging climatic conditions, the network broadly reflects the agricultural landscape in accordance with project objectives. Agricultural categories such as “orchards,” “meadows,” and “complex agricultural surfaces” are often well represented, though limitations in CLC classification likely lead to underestimation in mosaic agroecosystems, such as mixed olive groves and vineyards. An overrepresentation of “anthropic” areas indicated a tendency to situate apiaries in rural yet accessible locations. By combining spatial analyses with field observations and apiary-level data, a refined categorisation of land types and explicit consideration of beekeeping practices, such as nomadism, could strengthen the interpretative capacity of such network. The results underline the importance of spatial validation of stakeholder-driven monitoring to ensure ecological datasets are reliable, policy-relevant, and scientifically robust.

The success of animal species is shaped by a combination of ecological conditions and behavioural plasticity, with the latter being particularly crucial for the spread of invasive species. Megachile sculpturalis (Apoidea: Megachilidae), an East-Asian solitary bee introduced to France and subsequently spreading across Europe and North America, provides a case study. While its distribution is well-documented, the behavioural traits driving its success remain poorly understood. Our study aimed to explore behavioural patterns associated with its nesting cycle and potential expansion. In 2020, we conducted focal observations of individually marked females nesting in an artificial bee hotel. Daily recordings, based on ethograms, tracked females' activity at the site. We identified key behavioural units related to nesting goals and analysed the frequency and abundance of actions associated with each marked nest. Our results highlighted the significant effort females devote to nest-related actions, with 50-68% of all behaviours focused on nest building, suggesting any strategy of dispersion should be investigated in this context. While a typical nesting sequence was identified, individual variability indicated plastic nesting responses. Notably, females demonstrated a strong tendency to quickly shift their efforts to new nests following closure or abandonment, even provisioning multiple nests simultaneously. This ability to manage several nests at once may be crucial for establishing populations in invaded areas by rapidly expanding nesting efforts across multiple new sites during a single reproductive season. Our findings emphasize the contribution of behavioural studies in understanding reproductive strategies that influence a species' ability to settle in new environments and expand its range.

Anthropogenic environments are increasingly recognised for their potential to support pollinator diversity, especially through the strategic selection of ornamental plant species. This study investigated the ecological role of Salvia yangii (formerly Perovskia atriplicifolia) in supporting solitary bees, particularly species of the genus Anthidium, within urban green spaces in Milan (Italy). Field observations were conducted in both urban and rural sites to assess pollinator visitation rates, bee abundance, and plant traits relevant to nesting and foraging. S. yangii attracted a diverse assemblage of bee genera, with Anthidium spp. consistently recorded as dominant visitors. This preference is likely driven by the short corolla tube, which facilitates the access to nectar, and its dense coverage of trichomes, which may serve as essential nesting materials. The interaction was found to be stable across environments, suggesting that S. yangii provides reliable floral and structural resources. These findings highlight the potential of specific ornamental plants to contribute meaningfully to urban pollinator conservation. While the use of exotic species warrants caution, we propose that S. yangii may be suitable for inclusion in pollinator-friendly planting guidelines under controlled horticultural conditions, offering a promising model for enhancing urban biodiversity through informed plant selection.

Given the growing importance of assessing the condition of wild bees in agroecosystems, we focused on developing a BEE indicator that could be easily used by non-expert taxonomists to score bee diversity. Our goal was to create a tool suitable for farm-level use, one that does not require taxonomic expertise nor heavy field work. Since existing literature has emphasized the significance of environmental features surrounding any investigated site, we incorporated this aspect into our design. We began by identifying a user-friendly field tool to differentiate among bee morphogenera, then proceeded by developing a process for data analyses and interpretation. A protocol is also shared. Further on, we run a case-study testing this tool at 13 sites in three countries, differentiating farms based on farming practices (conventional or organic, as proxy of opposite conditions). The results confirmed that (a) a diagnostic table based on morphological similarities is a practical field tool that, in almost all cases, allows for accurate classification of a bee individual into a specific group (morphogenus); (b) the process of analysis, based on number of morphogenera and landscape composition reflects variability among bees and across sites; (c) evaluating environmental features is essential for placing the results of bee variability into the appropriate context.

In urbanized environments, the expansion of urban areas has led to the creation of fragmented green spaces such as gardens and parks. While these areas provide essential habitats for pollinators, they may also inadvertently concentrate specimens of different species, increasing opportunities for pathogen transmission. This study highlights the importance of investigating pathogen dynamics in urban ecosystems, focusing on managed pollinators, such as Apis mellifera Linnaeus, 1758, and their wild counterparts. Over a two-year monitoring period in Milan, Italy, we examined the interactions between pollinator populations in urban green spaces and the spillover of honeybee pathogens. Our findings confirm widespread RNA virus transmission between honeybees and wild pollinators, supporting the previous studies. Notably, the Acute Bee Paralysis Virus (ABPV) exhibited the highest prevalence across both sampling years, underscoring its significant role in pathogen dynamics. These results emphasize the need for regular research to mitigate pathogen spillover risks in urban pollinator communities and inform conservation strategies.

In honey bee diet, pollen is the primary source of proteins and essential nutrients. High pollen diversity and protein content support honey bee health, enhancing resistance to different stressors. Agroecosystem simplification, with few dominant species flowering for a limited period, can lead to a shortage of forage and a reduction in the variety and quantity of food. We therefore investigated how agroecosystem landscape characteristics influence pollen collection patterns. We collected beebread from 25 apiaries, located in Emilia-Romagna (Northeastern Italy), in March and June 2021 and 2022. We evaluated their pollen diversity and protein content and assessed the relationship with landscape heterogeneity and composition in a 1500 m radius around each apiary. A total of 138 pollen taxa were identified, predominantly from the Fabaceae, Rosaceae, and Asteraceae families. Pollen richness was significantly higher in June than in March for both years. Protein content, on the other hand, was higher in 2021 compared to 2022 and, for 2022 only, in June compared to March. Cluster analysis of the 25 sites according to their landscape characteristics revealed three distinct groups: Group 1 (mainly arable land), Group 2 (mixed arable land and forest), and Group 3 (arable land and permanent crops). Group 1 had lower landscape heterogeneity. Pollen composition did not differ significantly among groups, suggesting that honey bees might expand their foraging area (over the 1500 m radius that we consider) in response to landscape homogeneity, as observed in Group 1 areas. On the other hand, pollen diversity was highest in Group 3, likely due to the variety of fruit tree species and spontaneous flora.

Pollinators are a crucial group of organisms due to their role in the maintenance of environmental biodiversity and crop production. Pollinators may be very diverse; however, in temperate areas they are mainly insects, and the most active and important are certainly the bees. Not only the well-known honeybee: there are almost 2000 species of wild bees in Europe, and about 1000 just in Italy. There is an increasing public worry related to their decline and to the impact that this decline may have on agricultural production. The way public perception of the pollinator issue arises is generally neglected, especially by important stakeholders such as the farmers. Moreover, direct actions were not indicated by the policy till recently. We surveyed the main steps that possibly drove the current political perspective at the European and national (Italian) level. We found an increased boost toward healthier environments through the release of various documents. To look for changes that may include pollinator protection, we need to address the Common Agricultural Policies (CAPs), the tool that shapes the European agro-environments. A new CAP document has been recently released, and the Member States are moving toward the definition of eco-schemes to be adopted by farmers after payments. Italy placed pollinators in pole position with a dedicated eco-scheme: will pollinators finally be acknowledged?

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