Conference Agenda

Studies on pollinators and pollination primarily focus on agricultural areas due to their pivotal role in food production. Yet, understanding the current and future state of pollinator communities in agricultural areas requires a comparison of their status with that of other habitat types. For instance, the impact of climate warming on pollinators could vary across land uses and spatial scales, information that can be important for designing climate-resilient landscapes. Here we address this topic through a multiscale space-for-time approach spanning extensive climate and land-use gradients in Bavaria (Germany). We used DNA metabarcoding of Malaise trap samples and trap nest data collected in 179 study plots (forest, grassland, arable land, and settlement) embedded in 60 study regions (semi-natural, agricultural, and urban).

Malaise trap samples yielded 3,218 flower-visiting species from seven taxa, and trap nests contained 88,696 insect brood cells from 97 species. We analyzed community composition, abundance, taxonomic diversity (alpha, beta—community dissimilarity—, and gamma diversity) and functional diversity throughout land uses, climates and spatial scales, as well as the resulting pollination service. Our study reveals contrasting trends in pollinator diversity and pollination in different land-use types with climate, which give us hints of management options across spatial scales.

Pesticides are widely used in modern agriculture to produce food on large scales and at low cost. Concerns exist around impacts pesticides could have on biodiversity and associated ecosystem services, with a particular focus on bees in recent research and policy action. Here recent research investigating the hazards that pesticides may pose to pollination services provided by bees at field-realistic levels is discussed. We find that insecticides, but also fungicides and herbicides, can have implications for bee ecology and behaviour, and make recommendations for further research to inform risk assessment. We also investigate the range of mitigation measures available to reduce impacts of pesticides on bees, finding many commonly implemented measures lack full empirical support. For example, choosing times of day when pollinators are less active is recommended for application of many pesticides but is not widely supported in the literature. In addition, deciding when this is and whether it will reduce risk is complex and differs for different pollinator groups. Results are discussed in the context of both pesticide use and pollinator conservation, with the aim of integrating pollination service provision with crop protection.

There have been increasing concerns that the use of managed bees contributes to the spread of non-native genes and diseases, as well as depresses local bee populations through competition for nectar and pollen. A special situation is when the managed bees are a con-specific to a wild bee, yet a different sub-species. We studied the consequences of the multi-year use of managed bees for pollination of tomatoes, berries, and fruits in Sweden, with half of the matched sites having managed Bombus terrestris of non-native origin to boost pollination. Using genomics, we verified that escapees from the managed colonies appeared in the landscape, but we found no evidence of genetic introgression. When screening for eight pathogens and two parasites, our preliminary results (early part of the season) could not establish that introduced cultivated bumblebees have a negative impact on the prevalence and distribution of pathogens in local wild bumblebees. However, open screening found evidence of some viruses not appearing in native bees, and even very low levels of exotic pathogens and parasites in introduced bumblebee colonies can pose a risk. We discuss why our results may differ from other recent studies of the consequences of using managed non-native bees for pollination.

The proper management of urban green areas is pivotal for the protection of biodiversity and ecosystem services within cities. Urban agricultural areas are peculiar in this respect, as they are dominated by plant species cultivated for human consumption rather than wild species, yet can often harbor high levels of taxonomic and functional plant diversity. Due to the interdependency between flowering plants and pollinators, agricultural productivity is largely reliant on this interaction; there is thus particular interest in understanding how urban agriculture can contribute to pollinator conservation and benefit from the service they provide.

In this study, we sampled pollinators in 8 urban parks and 7 urban agricultural areas in the city of Bologna, in Northern Italy. The main goal was to model a city-wide pollinator species-habitat network. Specifically, we wanted to investigate the different roles of parks and urban agricultural areas in the structuring of the network (including their role as pollinator sink and source habitats towards each other), how these roles changed through the sampling season, and how local habitat features modulate these phenomena. Our work will contribute to the improvement of biodiversity-friendly management practices for urban green areas, especially for urban agriculture.

Animal pollination directly benefits the production of a wide share of crops consumed by humans. Despite the importance of pollinators in contributing to global food security and to diverse and nutritionally balanced diets, a comprehensive quantification of their role in determining food quality is lacking. Here, we conducted a systematic literature review and performed a set of multi-level meta-analyses to quantitatively summarise 190 experimental studies on the contribution of animal pollination to the quality of 48 globally important crops. Results indicate that pollinating animals significantly enhance the quality of food crops. In particular, they greatly contribute to improving crops organoleptic and marketability traits, such as size and shape, besides their nutritional value. In most cases, current activity of wild and/or managed pollinators is sufficient to ensure optimal food quality, although we report weak signals of a pollination deficit for organoleptic traits, which might indicate a potential pollination service decline across agroecosystems. Understanding the contribution of animal pollination to crop quality highlights the role of pollinators for global food security and promotes opportunities to conserve and manage pollinators in agricultural landscapes.

Pollination services are crucial for many wild plants and global food crops, but different crop species can vary in their dependence on pollination and pollinator species interactions can impact crop quality measures in different ways.

First, we present a comprehensive review of pollinator interactions with European honey bees (Apis mellifera) from 39 countries over the last 60 years. Results indicate that many honeybee interaction studies (39%) were not specifically designed to test competition, yet 86% of them discussed interactions between pollinator species, reported potential competition consequences, or linked honey bee behaviours to outcomes.

Second, we present field trial results focused on the efficacy of honey bees and native Australian stingless bees (Tetragonula carbonaria) to three model crops: blackberry (Rubus fruticosus), blueberry (Vaccinium virgatum), and raspberry (Rubus idaeus).

We found that the amount of conspecific pollen deposition is influenced by pollinator species identity and visit number, with native stingless bees outperforming honey bees in conspecific pollen deposition. Overall, these findings underscore the complexity of plant-pollinator relationships and the need for integrated management practices that consider both honey bees and native insects. Such an approach is crucial for optimizing pollination services in crops and ensuring resilient agricultural systems.