Plant-pollinator interactions are vital relationships involving mutual gains: animals (pollinators) collect food resources (mainly pollen and nectar) and their activities facilitate the reproduction of plants. About 90% of all flowering plants require pollination to reproduce, and 75% of food crops show increased production in result of pollination. Bees have a key role in the pollination process. Although most agricultural pollination is commonly attributed to honeybees, solitary bees also contribute decisively to crop pollination. The importance of bees in ecosystem services and the maintenance of life on the planet is counterbalanced by the increasing worldwide decline of these pollinators.

In the past years, declines in bee diversity have been documented in various regions, in relation to habitat destruction and fragmentation, insufficient floral resources and pesticide use. Brazil is the third leading producer of mango worldwide (43.8m tons/year), with the São Francisco Valley (located in the morphoclimatic domain of the Caatinga) accounting for 85% of Brazilian. Both mango and the passion fruit are exported from here to several Atlantic countries and depend on bee cross-pollination. Globally, 187 species of bees have been described in the Caatinga, most of them are endemic and rare taxa. The importance of the São Francisco Valley production to Atlantic countries makes knowledge of the interactions among bees (as drivers of production) and the agricultural system fundamental for sustainable production and protection strategies. In particular, studies in São Paulo state from the UNESP and the UFSCAR associated massive bee death to pesticide exposure. As serious as interfering with the survival and longevity of bees is the contamination of pesticides in bee products widely used by the population, such as honey or the fruits produced. Monitoring programs are thus under implementation on a global scale to analyse the causes of bee decline. Ground data about bee biodiversity, interspecies community interactions, pesticides in honey and fruits, and the impact of pesticides on bee behaviour and survival is lacking. The incipient data available in this domain also hampers the establishment of effective management and conservation actions preventing bee and crop yield decline. BEESNESS is a multidisciplinary collaborative project involving CIIMAR, Cardiff University (UK) and Brazilian universities UNICAMP and UNIOESTE. It was set to generate big data enhancing knowledge to understand and prevent bee decline in the São Francisco Valley. The team involves experienced complementary researchers in Brazilian bee ecology, environmental toxicology and chemistry, and omics approaches, who joined efforts to tackle this urgent need. BEESNESS main aims are to exchange expertise, skills and infrastructures to assess bee biodiversity in this eroded and overlooked biome, and in valuable fruit crops, as well as the relation to pesticide application in the region, under different climatic scenarios. Both natural areas and crops (conventional and non-conventional farming) of mango and passion fruit will be investigated. Knowledge about the local bee fauna will enable exploring the extent to which pesticides used in the conventional agricultural crops interfere with the dynamics of bee populations.