Marino Quaranta

The genus Lasioglossum Curtis, 1833 is the most diverse group of halictid bees and is widely distributed across the Palaearctic region. In the Mediterranean Basin, a recognized biodiversity hotspot, Lasioglossum is especially well represented, yet its taxonomy remains complex and often unresolved. This is particularly true in Italy, where the fauna of the Western part of the Mediterranean Basin is mixing with the Eastern part. Moreover, previous taxonomic studies on the species recorded in Italy are sporadic, scattered across different sources, and often published in languages other than Italian. As a result, identification tools remain fragmented and largely inaccessible to a broader audience. Through a thorough examination of both historical and recent material, together with a critical review of the relevant taxonomic literature, this study provides the first comprehensive revision of the Italian Lasioglossum fauna. 103 species are now recognised from Italy, including one taxon returned to species rank from its previous subspecific combination: Lasioglossum pseudocombinatum (Blüthgen, 1921) stat. rev. Thirteen taxa previously cited in the literature are here excluded or revised in their taxonomic status. Italy ranks as the third most species-rich country in Europe for Lasioglossum, following Greece and Spain. Despite this richness, the level of strict endemism is low (0.94%), confirming Italy’s complex biogeographic setting at the intersection of major faunal regions. The current assemblage is shaped more by colonisation and faunal exchange than by isolation or speciation. This study also includes the first complete identification key to all Italian species. By consolidating scattered data and providing accessible tools for species identification, it aims to promote further research on wild bee diversity in Italy and support conservation efforts in a context where taxonomic knowledge has long remained fragmentary.

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.

Plant–pollinator networks provide crucial insights into the mechanisms shaping the structure, stability, and ecosystem services of bee communities. Despite the Mediterranean basin being one of the world's richest regions for bee and plant diversity, it remains relatively understudied, with many islands largely overlooked in interaction studies. Here, we conducted an extensive survey of wild bees and their interactions with plants across four sites in Sardinia, the second–largest Mediterranean island, including two locations on Asinara Island with largely natural habitats and two sites in Nurra, a mainland area dominated by agroecosystems. In total, we recorded 122 wild bee species, including Hoplitis corsaria (Warncke, 1991), here reported for the first time from Italy, and six additional species newly recorded for Sardinia, highlighting the still incomplete exploration of the island's bee fauna. Bee diversity varied across sites, with higher richness at greater habitat heterogeneity, and at temporal scale, with consistent peaks of richness and diversity in May–July, likely according to variation in plant species richness but not in plant abundance. All bee–plant networks (divided by site and seasonal period) were highly specialized, modular, and non–nested, indicating low stability and potential vulnerability to disturbances. Network–level specialization, but not species–level specialization, varied among sites and also peaked in May–July, while marginally decreasing with plant species richness in the whole community. Since habitat heterogeneity was positively associated with percentage of both crop and urban cover, the observed patterns preliminarily suggested a role of anthropogenic disturbance on bee communities but not, or weakly, on network topology. Broader sampling across Sardinia will refine our understanding of habitat–driven effects.

Pollinators play a vital role in most terrestrial ecosystems, supporting wild plant communities and enhancing agricultural yields. However, despite their ecological and economic importance, they have been experiencing an alarming decline over the past decades. The Mediterranean region, known for harboring highly diverse communities of plants and pollinators, is particularly vulnerable due to intense anthropogenic pressures. Furthermore, the ecological roles of many floral visitors remain poorly understood, hindering conservation efforts. In response, in recent years, growing attention has been directed toward the contribution that citizens can give in support of pollinator research. An increasing number of projects have adopted a Citizen Science approach to enable large-scale data collection. The LIFE 4 Pollinators project (LIFE18/GIE/IT/000755) “Involving people to protect wild bees and other pollinators in the Mediterranean” aims to promote the conservation of pollinating insects and entomophilous plants across the Mediterranean region by fostering progressive changes in human practices that threaten wild pollinators. In addition to the implementation of several actions to raise awareness, the project launched a web platform to collect photographic records of flower–insect interaction from the public. The platform is expected to remain active for at least ten years, during which we encourage continuing record submissions by interested bodies. With this data paper we are making the current dataset freely accessible to anyone, committing to periodic online updates.

Bombus haematurus (Hymenoptera: Apidae), which arrived from the Balkan Peninsula, was first reported in Italy in 2020 in the Friuli Venezia Giulia region (FVG) (northeastern Italy) near the border with Slovenia. To study the spread and biology of the species, a survey was conducted at several sites of the FVG in the period 2023–2025. Bombus haematurus was recorded at 22 new sites across all four districts of the FVG (Trieste, Gorizia, Udine, and Pordenone), indicating its expansion towards the west. Bumblebees of this species were detected in plain and hilly areas at sites between 10 and 364 m a.s.l. They were observed more frequently at forest edges, undergrowth paths or clearings and meadows adjacent to woods, confirming the species is hylophilous. The activity of adults from February to July confirms that the bumblebee is an univoltine spring species. Specimens were observed foraging on the flowers of 19 wild and ornamental plants belonging to 12 families (in particular, Lamiaceae), confirming that the species is polylectic. The data collected indicate that B. haematurus are permanently established in the FVG and that a further spread of the species towards the west in the neighbouring Veneto region is likely.

Response to Krahner et al. (2025) Build the EU Pollinator Monitoring Scheme on robust evidence. Journal of Pollination Ecology 38(13): 183-185. https://doi.org/10.26786/1920-7603(2025)846 (this issue)

Bumblebees (Apidae: Bombus) are abundant pollinators in Mediterranean habitats; however, interaction networks with plants have not yet been investigated in large areas of Italy, including its islands. Here, we analyzed plant-bumblebee networks through seasonal transects in a suburban park and a nature reserve of Eastern Sicily. After molecular and morphological identification of bumblebees, we built bipartite networks extracting complementarity, niche overlap, modularity and nestedness. In total, we sampled 10 of the 15 species of Bombus known from Sicily. Richness was close to that predicted by accumulation curves, and no differences in community diversity were found between the two sites. At both sites, the networks were not nested, highly specialized and modular, with high complementarity and low niche overlap, again with no differences between sites. In both sites, species-level specialization varied considerably and was independent from sample size. The network topologies suggest a possible role of local interspecific competition and/or of interspecific morphological variation among generalist bumblebees. Comparison of previously published data revealed that networks in Mediterranean areas are more specialized than those with a continental climate. This suggests the possibility of increased competition and/or phenotypic variation under harsh Mediterranean conditions. The vulnerability of the Mediterranean basin to droughts caused by climate change calls for detailed studies on pollinator-plant networks for conservation plans.

Despite its global importance for the maintenance of healthy ecosystems and its contribution in providing economic benefits to human society, the clade Anthophila is in severe decline worldwide. In this context, counteracting the decline in Apoidea is of fundamental importance. Honey bee density and beekeeping are believed to negatively impact wild bee populations, mostly through competition for food sources. In this study, interspecific trophic competition was investigated using the still seldom exploited approach of a palynological analysis combined with a metabarcoding analysis of the pollen gathered by both managed honey bees and wild bees in three Italian national parks. The entire trophic network was identified as highly specialized (H2′ = 0.933). The results obtained suggest that, overall, wild bee species are sustained by different pollen sources than honey bees. This low sharing of resources could be due to the natural trend occurring in natural populations, where species tend to minimize the competitive overlap through niche differentiation or niche complementarity as a result of coevolution. National parks play a fundamental role in animal and plant species protection and conservation. Therefore, plans should focus on evaluating honey bee densities in the interests of achieving less intensive, more traditional, and sustainable beekeeping, as well as habitat restoration, to promote the survival and reproduction of wild bee populations.

Wild bee communities of Sardinia and Corsica, two Mediterranean islands, have been relatively understudied. In this article, Lasioglossum inexpectatum sp. nov., which is known exclusively in Sardinia and Corsica, is described, emphasizing the importance of ongoing research and conservation efforts to protect the unique wild bee biodiversity in the Mediterranean basin.

The area sourrounding the Mediterranean basin is recognised as a major biodiversity hotspot for bees, and Italy is amongst the European countries with the highest bee species richness. Detailed knowledge of bee distribution is crucial for understanding bee biology and designing tailored conservation strategies, but is still insufficient in southern European countries, especially in Italy. We report recent finds of 48 bee species that yield significant novelties for the Italian bee fauna. Eight species, namely Andrena confinis Stöckhert, Anthidiellum breviusculum Pérez, Coelioxys alatus Foerster, Lasioglossum algericolellum Strand, Megachile lapponica Thomson, Megachile opacifrons Pérez, Megachile semicircularis auct. nec Zanden and Trachusa integra Eversmann are reported as new for Italy. In addition, Andrena binominata Smith, Andrena compta Lepeletier, Colletes acutus Pérez, Lasioglossum strictifrons Vachal, Rhodanthidium siculum Spinola and Rhodanthidium sticticum Fabricius are newly recorded from mainland Italy, Osmia heteracantha Pérez from Sardegna and Nomada flavopicta Kirby from Sicilia. We also report significant range extensions for other bee species and recent records of species that had long gone unrecorded in Italy. The combination of morphology and DNA barcoding provided reliable identifications even for the most challenging specimens. As several of our records come from areas neglected by bee experts in the past, this study stands out as a key indicator of a bee faunistic richness still awaiting discovery and hopefully it will stimulate the interest of taxonomists and stakeholders in pursuing bee research in Italy in the near future.