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Sicily (Italy) is an important hotspot diversity for bees and new species records are constantly reported for the island. Here, we rediscovered after 45 years without records, the occurrence in Eas...

In Sardinia, the second largest Mediterranean island, 316 species of bees are known. Here, for the first time, the following 20 taxa are reported: Colletes cunicularius (Linnaeus, 1761), and C. eous Morice, 1904 (Colletidae), Andrena humilis Imhoff, 1832, A. granulosa Pérez, 1902, A. cineraria (Linnaeus, 1758), A. pallitarsis Pérez, 1903, A. rugulosa Stöckhert, 1935, A. savignyi Spinola, 1838, and A. tenuistriata Pérez, 1895 (Andrenidae), Sphecodes reticulatus Thomson, 1870 (Halictidae), Lithurgus tibialis Morawitz, 1875, Chelostoma emarginatum (Nylander, 1856), Dioxys cinctus (Jurine, 1807), Coelioxys caudatus Spinola, 1838, C. obtusus Pérez, 1884, and Megachile ericetorum (Lepeletier, 1841) (Megachilidae), and Nomada melathoracica Imhoff, 1834, N. pulchra Arnold, 1888, Eucera proxima Morawitz, 1875 and Tetralonia malvae (Rossi, 1790) (Apidae). N. pulchra is reported for the first time in Italy.

The decline of pollinators may alter the complex system of interactions that they establish with flowering plants, with potential negative consequences on both partners. Within this context, network analysis may be a useful tool to study ecological properties of plant-pollinator interactions and to evaluate the outcomes of conservation actions. Three conservation measures were implemented within the European LIFE + PP-ICON project to support the local pollinator community of a population of the rare plant Dictamnus albus in a protected area near Bologna, Italy. Artificial nesting sites were installed to support solitary bees, populations of native plants were reinforced to increase foraging resources for pollinators, and colonies of bumblebees reared from wild queens were released in the study area. In this work we evaluate the effects of these conservation actions on plant-pollinator networks over a period of four years, comparing a pre- (2011–2012) and a post-conservation (2013–2014) action period. The overall network generalisation increased after the implementation of conservation measures and interactions were more evenly distributed. Module composition significantly changed between the two periods, showing a marked rewiring of interactions. D. albus was a module hub both before and after conservation actions, thus emerging as an important node within its own module. In addition, some plant and pollinator species directly targeted by conservation measures became module connectors, highlighting their increased importance in linking different modules. Finally, the reinforcement of plant and pollinator populations led to increased flower visitation. These results indicate that conservation actions affected species both directly and indirectly and that the network of interactions has potentially increased its robustness and resilience towards possible species loss. This study highlights ways in which network analysis can be used to measure changes in plant-pollinator interactions in response to conservation actions.

Biodiversity loss has been demonstrated to have direct impacts on human welfare. However, policymakers need to refer to commonly accepted standards to monitor biodiversity, especially to direct fund granting. With the aim of collating information for the creation of a reliable pollinators’ one, we screened available indicators. Our first criterion was selecting indicators applied in agricultural contexts and recognised by a governmental body. Further, we included indicators referring to any arthropod taxa and approved at least by national bodies. We focused on these two groups based on the concept that a new indicator should include both, approved standards and an ecological level of potential significance for insect pollinators. Among the environmental indicators considered in the last CAP (European Common Agriculture Policy 2014-2020), two are referred for measuring the success of RDPs (EU countries Rural Development Programmes) actions to sustain biodiversity: FBI (Farmland Bird Index) and HNV (High Nature Value) farming. On the other hand, many indicators using arthropods exist, and we considered those applied by the Italian national institute ISPRA (Istituto Superiore per la Protezione e Ricerca Ambientale). These indicators include butterflies, syrphid flies, ground beetles, or a combination of abiotic and biotic information (as for the soil or waterbodies). We compared survey scale, monitoring scheme, type of environment, sampling effort, expected arthropod population, taxonomic level of data. As a common approach, we identified the combination of a territorial analysis by remote tools (e.g. GIS) and animal taxa surveys. Both FBI and HNV farming, for different reasons, resulted poorly conclusive on evaluating the national measures aimed at environmental improvement. The first, because the landscape context that is considered is poorly related to that of a farm. The second, because it can be differently interpreted by each country. The strength of indicators including arthropods emerges in the simultaneous inclusion of biotic and abiotic components. However, most of them just refer to confined environments (e.g. grasslands, riversides). Pollinators’ sensitivity to changes at the micro-habitat level is widely recognised, even helping to distinguish different methods of agricultural management. To develop a biodiversity indicator based on pollinators, we suggest to improve knowledge on local pollinator species and their environmental requirements, coupled with wide (in time and space) national monitoring programs.

There is increasing interest in evaluating biodiversity to preserve ecosystem services. Researchers can sustain policymakers by providing tools, such as indexes and indicators, that need constant implementation to become accepted standards. Implementation may vary from re-evaluation of existing indicators to introduction of new ones based on emerging threats to biodiversity. With the aim of contributing to the compelling need to estimate and counterbalance pollinator loss, we screened existing bioindicators. We first selected indexes/indicators applied to agricultural contexts and concurrently endorsed by a regulatory agency. We then extended our analysis to indexes/indicators based on arthropod taxa and formally recognized at least by national bodies. Our procedure identified a combination of surveys of various animal taxa and remote landscape analyses (e.g., using a GIS and other cartographic tools). When the animals are arthropods, most indexes/indicators can only address confined environments (e.g., grasslands, riversides). Indicator strength was improved by the simultaneous inclusion of biotic and abiotic components. Pollinator sensitivity to changes at micro-habitat level is widely appreciated and may help distinguish agricultural practices. A biodiversity index based on pollinators, including a wide monitoring scheme supplemented by citizen science, is currently fostered at the European level. The results obtained using such an index may finally enable focusing of strategic funding. Our analysis will help to reach this goal.

Generalist flowers are visited by a broad variety of insects that function as pollinators, occasional visitors and as pollen and/or nectar robbers. Moreover, among legitimate pollinators the pollination efficiency can be different. Nectar greatly affects visitor behaviour and fidelity to a certain species, influencing plant reproductive effort. In this study we have investigated a generalist system (Gentiana lutea L.), examining the role of flower visitors and quantifying the contribution of each pollinating taxon in three natural populations. In order to verify the level of generalization, we introduce an index of Pollinator Performance (PoP), based on insect visitation rate and cross-pollen transport efficiency. Our results confirm the high degree of pollinator-generalization of the study species. Nevertheless, flower visitors show various degree of pollinating performance, mainly defined by their sedentary versus dynamic behaviour. Sedentary insects enhance geitonogamous pollen transfer, which results in reduced seed set and pollen limitation. In particular, an unusual sluggish behaviour was observed in bumblebees feeding on nectar. The hexose-rich abundant nectar offered by G. lutea flowers is remarkably rich in proline and β-alanine amino acids: this composition presumably influences feeding choice and insect dynamism, likely exerting a narcotic effect on pollinators. The consequences on plant fitness are discussed in an evolutionary perspective.

Bees collect pollen as an important resource for offspring development while acting as pollen vectors for the plants visited. Foraging preferences of pollinators together with plant species availability shape the web of interactions at the local scale. In this study, we focused on the bee pollinator community of a population of the rare protected perennial herb Dictamnus albus, with the aim to characterise the pollen preferences and the foraging niche overlap among species through time. Bees were sampled during four consecutive years in a natural population of D. albus, throughout the blooming period of the plant species. We performed an analysis of insect pollen loads to investigate the interactions with the study species and the co-flowering plants in the area, and to evaluate the degree of foraging overlap among pollinators. Over the study years, all bee species showed a high fidelity to D. albus (60–80%), even if some taxa preferentially collected pollen from other flowering species. The foraging niche overlap in the pollinator community decreased together with an increased diversity of co-flowering plant species. The results obtained indicate that bees preferentially forage on D. albus in the studied area, but that co-flowering species contribute to complement their diet and likely reduce competition for foraging resources. It appears therefore important to maintain a high diversity of co-flowering plants to preserve the diversity in the studied pollinator community of D. albus.

Land-use change and intensification threaten bee populations worldwide, imperilling pollination services. Global models are needed to better characterise, project, and mitigate bees' responses to these human impacts. The available data are, however, geographically and taxonomically unrepresentative; most data are from North America and Western Europe, overrepresenting bumblebees and raising concerns that model results may not be generalizable to other regions and taxa. To assess whether the geographic and taxonomic biases of data could undermine effectiveness of models for conservation policy, we have collated from the published literature a global dataset of bee diversity at sites facing land-use change and intensification, and assess whether bee responses to these pressures vary across 11 regions (Western, Northern, Eastern and Southern Europe; North, Central and South America; Australia and New Zealand; South East Asia; Middle and Southern Africa) and between bumblebees and other bees. Our analyses highlight strong regionally-based responses of total abundance, species richness and Simpson's diversity to land use, caused by variation in the sensitivity of species and potentially in the nature of threats. These results suggest that global extrapolation of models based on geographically and taxonomically restricted data may underestimate the true uncertainty, increasing the risk of ecological surprises. Fil: De Palma, Adriana. Natural History Museum; Reino Unido. Imperial College London; Reino Unido Fil: Abrahamczyk, Stefan. Universitat Bonn; Alemania Fil: Aizen, Marcelo Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina Fil: Albrecht, Matthias. Institute for Sustainability Sciences; Suiza Fil: Basset, Yves. Smithsonian Tropical Research Institute; Panamá Fil: Bates, Adam. Nottingham Trent University; Reino Unido Fil: Blake, Robin J.. University of Reading; Reino Unido Fil: Boutin, Céline. Carleton University; Canadá Fil: Bugter, Rob. Wageningen University and Research; Países Bajos Fil: Connop, Stuart. University of East London; Reino Unido Fil: Cruz López, Leopoldo. El Colegio de la Frontera del Sur; México Fil: Cunningham, Saul A.. CSIRO Exploration and Mining; Australia Fil: Darvill, Ben. University of Stirling; Reino Unido Fil: Diekötter, Tim. Geomar-Helmholtz Centre for Ocean Research Kiel; Alemania. University Marburg; Alemania. Institute of Integrative Biology; Suiza Fil: Dorn, Silvia. ETH Zurich; Suiza Fil: Downing, Nicola. Royal Society for the Protection of Birds; Reino Unido Fil: Entling, Martin H.. Universitat Koblenz; Alemania Fil: Farwig, Nina. Universitat Phillips; Alemania Fil: Felicioli, Antonio. Università degli Studi di Pisa; Italia Fil: Fonte, Steven J.. State University of Colorado - Fort Collins; Estados Unidos Fil: Fowler, Robert. University of Sussex; Reino Unido Fil: Franzén, Markus. Helmholtz Centre for Environmental Research; Alemania Fil: Goulson, Dave. Universität Göttingen; Alemania Fil: Grass, Ingo. Universität Göttingen; Alemania Fil: Hanley, Mick E.. University of Iowa; Estados Unidos Fil: Hendrix, Stephen D.. University of Iowa; Estados Unidos Fil: Herrmann, Farina. Universität Würzburg; Alemania Fil: Herzog, Felix. Institut for Sustainability Sciences; Suiza Fil: Holzschuh, Andrea. Universität Würzburg; Alemania Fil: Jauker, Birgit. Justus-Liebig University; Alemania Fil: Kessler, Michael. Institut für Systematische und Evolutionäre Botanik; Suiza Fil: Knight, M.E.. Plymouth University; Reino Unido Fil: Kruess, Andreas. Federal Agency for Nature Conservation; Alemania Fil: Lavelle, Patrick. Centre National de la Recherche Scientifique. Institut de Recherche pour le Développement; Francia. Centro Internacional de Agricultura Tropical; Colombia Fil: Le Féon, Violette Alice Marie. Institut National de la Recherche Agronomique; Francia Fil: Lentini, Pia. University of Melbourne; Australia Fil: Malone, Louise A.. New Zealand Institute for Plant and Food Research Ltd; Nueva Zelanda Fil: Marshall, Jon. Marshall Agroecology Ltd; Reino Unido Fil: Pachón, Eliana Martínez. Universidad Nacional de Colombia; Colombia Fil: McFrederick, Quinn S.. University of California; Estados Unidos Fil: Morales, Carolina Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina Fil: Mudri Stojnic, Sonja. University of Novi Sad; Serbia Fil: Nates Parra, Guiomar. Universidad Nacional de Colombia; Colombia Fil: Nilsson, Sven G.. Lund University; Suecia Fil: Öckinger, Erik. Swedish University of Agricultural Sciences; Suecia Fil: Osgathorpe, Lynne. RSPB; Reino Unido Fil: Parra-H, Alejandro. Universidad Nacional de Colombia; Colombia. Corporación para la Gestión de Servicios Ecosistémicos, Polinización y Abejas; Colombia Fil: Peres, Carlos A.. University of East Anglia; Reino Unido Fil: Persson, Anna S.. Lund University; Suecia Fil: Petanidou, Theodora. University of the Aegean; Grecia Fil: Poveda, Katja. Cornell University; Estados Unidos Fil: Power, Eileen F.. Trinity College Dublin; Irlanda Fil: Quaranta, Marino. Consiglio per la Ricerca in Agricoltura e l'Analisi del l'Economía Agraria; Italia Fil: Quintero, Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina Fil: Rader, Romina. University of New England; Australia Fil: Richards, Miriam H.. Brock University; Canadá Fil: Roulston, Tai. University of Virginia; Estados Unidos Fil: Rousseau, Laurent. Université du Québec a Montreal; Canadá Fil: Sadler, Jonathan P.. University of Birmingham; Reino Unido Fil: Samnegård, Ulrika. University of Birmingham; Reino Unido Fil: Schellhorn, Nancy A.. CSIRO Exploration and Mining; Australia Fil: Schüepp, Christof. University of Bern; Suiza Fil: Schweiger, Oliver. Helmholtz Centre for Environmental Research; Alemania Fil: Smith Pardo, Allan H.. United States Department of Agriculture; Estados Unidos. Universidad Nacional de Colombia; Colombia Fil: Steffan Dewenter, Ingolf. Universität Würzburg; Alemania Fil: Stout, Jane C.. Trinity College Dublin; Irlanda Fil: Tonietto, Rebecca K.. Northwestern University; Estados Unidos. Chicago Botanic Garden; Estados Unidos Fil: Teja, Tscharntke. Universität Göttingen; Alemania Fil: Tylianakis, Jason M.. Imperial College London; Reino Unido. University of Canterbury; Nueva Zelanda Fil: Verboven, Hans A. F.. Katholikie Universiteit Leuven; Bélgica Fil: Vergara, Carlos H.. Benemérita Universidad Autónoma de Puebla; México Fil: Verhulst, Jort. No especifíca; Fil: Westphal, Catrin. Universität Göttingen; Alemania Fil: Yoon, Hyung Joo. National Institute of Agricultural Science; Corea del Sur Fil: Purvis, Andy. Natural History Museum; Reino Unido. Imperial College London; Reino Unido

A male specimen of Bombus terrestris (L. 1758) showing an intermediate colour between the subspecies xanthopus Kriechbaumer 1870 endemic to Corsica and the subspecies terrestris ubiquitous in the mainland was found within samples collected in 1999 on the Tuscan coast. Hybrid specimens between these subspecies are common on some of the islands of the Tuscan archipelago, while others only have pure populations. The finding is significant as it could signal the spread of the subspecies xanthopus_to the mainland. We consider and discuss the circumstances of the finding.

The interplay between insect and plant traits outlines the patterns of pollen transfer and the subsequent plant reproductive fitness. We studied the factors that affect the pollination efficiency of a pollinator community of Dictamnus albus L. by evaluating insect behaviour and morphological characteristics in relation to flowering phenology. In order to extrapolate the pollinator importance of single taxa and of the whole pollinator guild, we calculated an index distinguishing between potential (PPI) and realized (RPI) pollinator importance. Although the pollinator species spectrum appeared rather constant, we found high intra- and inter-annual variability of pollinator frequency and importance within the insect community. Flower visitation rate strictly depended on insect abundance and on the overlap between their flying period and flower blooming. All the pollinators visited flowers from the bottom to the top of the racemes, excluding intra-plant geitonogamous pollination, and most of them showed high pollen fidelity. Only medium large-sized bees could contact the upward bending stiles while feeding on nectar, highlighting a specialisation of the plant towards bigger pollinators. Moreover, we found evidence of functional specialisation, since all pollinators were restricted to a single taxonomic group (order: Hymenoptera; superfamily: Apoidea). Both the PPI and RPI indices indicate Habropoda tarsata as the most important pollinator of D. albus. Following hand cross-pollination experiments we revealed the presence of pollination limitation in 1 of the 3 years of field study. We discuss this result in relation to flowering abundance and to possible mismatches of phenological periods between plants and insects.

Although an extensive research has been done on the contribution of wild insects to apple pollination, most of these studies did not evaluate the effect of the surrounding landscape context on local pollinator communities. Our aim was to compare communities of wild bees in 31 equally managed apple orchards located in three contrasting landscape types (either dominated by apple, forest, or grasslands) and along an elevation gradient and to test a potential interaction between landscape context and elevation. The study was carried out in 2009 in Trentino (NE Italy), one of the major apple growing areas of Europe with ∼12,000 ha of commercial orchards distributed between 150 and 950 m a.s.l. We found that apple-dominated landscapes drastically reduced wild bee species richness and abundance in the orchard compared to landscapes dominated by either grassland or forest. Forest-dominated landscapes benefited local species richness more than grassland-dominated landscapes, while abundance did not differ between grassland and forest. Total species richness and abundance further declined with increasing elevation, while no interactive effect was found between temperature and landscape context. The abundance of Apis mellifera in the apple-dominated landscapes was two to four times higher than in the landscapes dominated by forest and grasslands, respectively. Measures to restore natural pollinator communities by providing suitable habitats around the orchard would not only benefit conservation of general biodiversity, but would probably also contribute to reduce the dependence of apple pollination on managed honey bees.

Papilionaceous flowers present functional traits commonly associated to the so-called “bee-syndrome”. Despite this evolutionary specialization, many legume species are visited by a large number of insect species. In a sample of seven perennial Mediterranean legumes we focus on the ecological aspects of plant-pollinator interactions. Our aim is to compare the degree of specialization of pollination systems among species showing similar floral traits associated with bee pollination. In particular we ask the following questions: (1) Do all flower visitors act as pollinators? (2) Are pollinators equally important? and (3) Is there any relationship between the degree of specialization of plant-pollinator system and plant fitness? We describe the spectrum of visitors and identify the potential pollinators by observing insects’ behaviour on flowers. The diversity of each population’s insect assemblage (flower visitors and potential pollinators) is calculated in order to estimate to which degree pollination systems are specialized. The importance value (PI) for main taxa of potential pollinators is computed considering both quality and quantity components of the pollination service: insect fidelity and relative abundance. Pollinator assemblages show different values of importance and dominance, revealing various degrees of plant-pollinator specificity. Visitors’ and pollinators’ diversity is negatively correlated with fruiting success, while there is a positive relation between maximum pollinator importance value and fruit set, suggesting the tendency towards a positive relationship between pollinator specificity and reproductive success.

Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of species' threat status or population time series are dominated by charismatic species. The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project - and avert - future declines. We describe and assess a new database of more than 1.6 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database contains measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35) biodiversity hotspots and 16 (of 17) megadiverse countries. The database contains more than 1% of the total number of all species described, and more than 1% of the described species within many taxonomic groups - including flowering plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans and hymenopterans. The dataset, which is still being added to, is therefore already considerably larger and more representative than those used by previous quantitative models of biodiversity trends and responses. The database is being assembled as part of the PREDICTS project (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems - www.predicts.org.uk). We make site-level summary data available alongside this article. The full database will be publicly available in 2015. The collation of biodiversity datasets with broad taxonomic and biogeographic extents is necessary to understand historical declines and to project - and hopefully avert - future declines. We describe a newly collated database of more than 1.6 million biodiversity measurements from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. © 2014 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.