The bee family Megachilidae includes over 3000 species (~20% of the bees in the world) including many important wild and managed pollinators. The classification and evolutionary history of this family are poorly understood and species-level identification is difficult for many groups. This project will analyze the systematics, taxonomy, biology and evolutionary history of the entire family with special emphasis on the tribe Anthidiini. The research involves two inter-related projects: (1) analysis of the evolutionary history of the group using morphological and molecular data and (2) analysis of the species-level taxonomy of select, speciose genera. These projects are tightly interwoven because evolutionary history provides the basis for a stable, species-level classification. Results (including illustrated interactive keys, online databases, species-level catalogs) will be made available as web-accessible digital resource that will be of considerable use to pollination and conservation biologists. Efforts to diversify crop pollinators and to monitor pollinator services in natural, as well as agricultural ecosystems, will be strengthened through knowledge of megachilid behavior, floral preferences, nesting habits, and distributions.
Bees are among the most important pollinators in both natural and agricultural settings. Bees provide pollination services for an enormous range of crops including cantaloupe, cocoa, coffee, kiwi, passion fruits, squashes, pumpkins, watermelons, apples, peaches and many others. The bee family Megachilidae includes some of the most important wild and managed pollinators, such as leaf-cutter bees, mason bees, and orchard bees. This study will greatly improve our ability to identify (and therefore manage) native pollinators as well as monitor native pollinator populations. The grant will provide training of a new generation of bee researchers with expertise in bee taxonomy. The project will involve substantial collaboration with entomologists in developing African countries.
Bees are the most important group of pollinating animals on earth. Bees arose over 120 million years ago and have since diversified into a bewildering 20,000 described species. They are enormously important economically as well. A recent study estimated the economic value of bee pollination to be €153 billion/year ($202 billion/year) on a worldwide basis. Both managed and wild bees contribute significantly to pollination of the fruits, nuts, berries, and stimulants (e.g, coffee) that make up an estimated 1/3 of the human diet. Our NSF-funded research project focused on the second largest family of bees, the Megachilidae (leaf-cutter, mason, and wool-carder bees). These bees are particularly important managed pollinators because their nests can be transported and nest sites can be augmented using trap-nests. Some species (such as Megachile rotundata and Osmia lignaria) are commercially important managed pollinators (in alfalfa and orchards, respectively). Megachilidae are second only to Apidae as managed pollinators. Megachilids are of additional importance because most invasive bees belong to this family. Despite their importance, megachilid taxonomy remains poorly understood. Prior to our study, there was no higher-level phylogenetic framework, key genera were unrevised, most existing revisions were out of date, and species-level identifications were impossible for many regions of the world. Our project focused on two related aspects of megachilid biodiversity: (1) understanding their phylogenetic (evolutionary) relationships based on molecular and morphological data and (2) conducting taxonomic studies of Megachilidae to make the identification of these important pollinators possible. The first objective of the project, understanding phylogenetic relationships, was accomplished by sequencing genes and analyzing morphological variation from a wide variety of species collected from around the world. For each species, we sequenced a standard set of phylogenetic markers, primarily from the nuclear genome. We aligned these sequences and then analyzed them using cutting-edge methods for reconstructing phylogenies. Our results (based on both morphlogical and molecular data) provided the first robust phylogeny for the family and helped resolve the phylogenetic affinities of enigmatic taxa (such as Fideliinae, Lithurginae, and several genera of Osmiini). Using our phylogeny, we were able to reconstruct the historical biogeography of megachilid bees, understand more about the evolution of host-plant choice, and identify lineages of Megachilidae that are evolving at unusually high rates. These results have lead to a much better understanding of megachilid diversity on a global scale. Our results have been published in important journals in the field of biology. The second objective of the project, to conduct taxonomic studies of these important managed pollinators, resulted in 15 publications including taxonomic notes, geographic range expansions, new species descriptions, reports on invasive species, and comprehensive taxonomic revisions. Making identification of pollinators available to a broad spectrum of users is essential given the shortage of trained bee taxonomists. One way to overcome this taxonomic impediment is to develop interactive, web-based identification tools. We have made available via the Discover Life website (www.discoverlife.org) a fully illustrated key to eastern North American species of Anthidium, a guide to the North American genera of Megachilidae, a guide to Nearctic Anthidiellum, and we are in the process of completing a guide to the Nearctic Dianthidium. These resources will allow both bee specialists and non-bee specialists to reliably identify megachilid bees to the species level. Our study also supported the infrastructure for science in the United States by making available specimen records for 44,350 anthidiine specimens representing 662 species and 10,032 localities in 103 countries via the Global Biodiversity Information Facility (GBIF). A digital library of type images has also been developed. Our NSF-funded project has led to the training of two postdocs (Victor Gonzalez and Christophe Praz), one of whom is of Hispanic descent, three graduate students (Jessica Litman, Margarita Lopez-Uribe, and Jonathan Koch), one of whom is of Hispanic descent, and ten undergraduate students (Carly Yates, Emily Spendlove, Camden Hunt, Skyler Burrows, Erica Stephens, Rochelle Cummings, Robin Pendery, Michael Orr, Andrew Debevec, and Lori Moshman), six of whom are women. Post-docs and graduate students associated with this project have gone on to obtain teaching and research positions, and several undergraduates have gone on to pursue higher degrees in science and engineering.
