The role of citizen science in addressing grand challenges in food and agriculture research.

The power of citizen science to contribute to both science and society is gaining increased recognition, particularly in physics and biology. Although there is a long history of public engagement in agriculture and food science, the term 'citizen science' has rarely been applied to these efforts. Similarly, in the emerging field of citizen science, most new citizen science projects do not focus on food or agriculture. Here, we convened thought leaders from a broad range of fields related to citizen science, agriculture, and food science to highlight key opportunities for bridging these overlapping yet disconnected communities/fields and identify ways to leverage their respective strengths. Specifically, we show that (i) citizen science projects are addressing many grand challenges facing our food systems, as outlined by the United States National Institute of Food and Agriculture, as well as broader Sustainable Development Goals set by the United Nations Development Programme, (ii) there exist emerging opportunities and unique challenges for citizen science in agriculture/food research, and (iii) the greatest opportunities for the development of citizen science projects in agriculture and food science will be gained by using the existing infrastructure and tools of Extension programmes and through the engagement of urban communities. Further, we argue there is no better time to foster greater collaboration between these fields given the trend of shrinking Extension programmes, the increasing need to apply innovative solutions to address rising demands on agricultural systems, and the exponential growth of the field of citizen science.

Phylogeny, new generic-level classification, and historical biogeography of the Eucera complex (Hymenoptera: Apidae).

The longhorn bee tribe Eucerini (Hymenoptera: Apidae) is a diverse, widely distributed group of solitary bees that includes important pollinators of both wild and agricultural plants. About half of the species in the tribe are currently assigned to the genus Eucera and to a few other related genera. In this large genus complex, comprising ca. 390 species, the boundaries between genera remain ambiguous due to morphological intergradation among taxa. Using ca. 6700 aligned nucleotide sites from six gene fragments, 120 morphological characters, and more than 100 taxa, we present the first comprehensive molecular, morphological, and combined phylogenetic analyses of the 'Eucera complex'. The revised generic classification that we propose is congruent with our phylogeny and maximizes both generic stability and ease of identification. Under this new classification most generic names are synonymized under an expanded genus Eucera. Thus, Tetralonia, Peponapis, Xenoglossa, Cemolobus, and Syntrichalonia are reduced to subgeneric rank within Eucera, and Synhalonia is retained as a subgenus of Eucera. Xenoglossodes is reestablished as a valid subgenus of Eucera while Tetraloniella is synonymized with Tetralonia and Cubitalia with Eucera. In contrast, we suggest that the venusta-group of species, currently placed in the subgenus Synhalonia, should be recognized as a new genus. Our results demonstrate the need to evaluate convergent loss or gain of important diagnostic traits to minimize the use of potentially homoplasious characters when establishing classifications. Lastly, we show that the Eucera complex originated in the Nearctic region in the late Oligocene, and dispersed twice into the Old World. The first dispersal event likely occurred 24.2-16.6 mya at a base of a clade of summer-active bees restricted to warm region of the Old World, and the second 13.9-12.3 mya at the base of a clade of spring-active bees found in cooler regions of the Holarctic. Our results further highlight the role of Beringia as a climate-regulated corridor for bees.