Biology, genetic diversity, and conservation of wild bees in tree fruit orchards

Authors: KLINE, OLIVIA - University Of Arkansas; PHAN, NGOC - Vietnam Nationall University; PORRAS, MITZY - Pennsylvania State University; JOSHUA CHAVANA - University Of Arkansas; COLEMAN LITTLE - University Of Arkansas; LILIA STEMET - University Of Arkansas; ROSHANI S. ACHARYA - University Of Arkansas; DAVID J. BIDDINGER - Pennsylvania State University; Reddy, Gadi V.P.; RAJOTTE, EDWIN - Pennsylvania State University

Submitted to: Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/8/2022
Publication Date: 12/24/2022
Citation: Kline, O., Phan, N.T., Porras, M.F., Chavana, J., Little C.Z., Stemet, L., Acharya R.S., Biddinger D.J., Reddy, G.V., Rajotte, E.G., Neelendra K.J. 2022. Biology, genetic diversity, and conservation of wild bees in tree fruit orchards. Biology. 12(1):31. https://doi.org/10.3390/biology12010031.
DOI: https://doi.org/10.3390/biology12010031

Interpretive Summary: Fruit and tree nut cropping systems benefit greatly from the pollination service of bees. Managed honey bees have long been used for this service, but the supplementation of orchards with non-Apis species can improve yields and benefit many local wild ecosys-tems. Bees across many families can be found in orchards, and many of these species, especially the solitary bees, are rarely studied or surveyed. These bee species can face multiple environmental stressors, from pesticide exposure, pathogen and par-asite spread, and the loss of floral resources and nesting sites. Though non-Apis bees can require different management and conservation measures than honey bees, many mitigation strategies can support honey bees, other managed bees, and a high diversity of wild bees. Growing evidence supports the importance of conserving habitat with diverse floral and nesting resources within close proximity of apple orchards and other insect-pollinated crops to support a diverse assemblage of wild pollinators and provide optimal pollination services. Reducing pesticide use and providing unsprayed floral plantings can also help protect bees from exposure to toxins. More research is needed to understand the specific nesting re-quirements of more bee species and how to best manage farming landscapes to provide for their needs. These mitigation measures are important, however, for protecting ro-bust pollinator communities and maintaining their pollination service for orchard crop production.

Technical Abstract: Different species of bees provide essential ecosystem services by pollinating several agricultural crops, including tree fruits. Many fruits and nuts depend on insect pollination, primarily wild and managed bees. In different geographical regions where orchard crops are grown, fruit growers re-ly on wild bees in farmscape and use orchard bees as alternative pollinators. Orchard crops such as apples, pears, plums, apricots, etc. are mass flowering crops and attract many different bee species during their bloom period. Many bee species that are found in orchards emerge from overwintering as the fruit trees start flowering in spring, and the active duration of these bees aligns very closely with the blooming time of fruit trees. In addition, most of the bees in orchards are short-range foragers and tend to stay in the fruit crops that need to be pollinated. However, the importance of orchard bee communities has not been well-understood, and many challenges in maintaining the bee population remain. This comprehensive review paper summarizes the dif-ferent types of bees commonly found in tree fruit orchards in the fruit-growing regions in the United States, their bio-ecology, and genetic diversity. Additionally, recommendations for the manage-ment of orchard bees, different strategies for protecting them from multiple stressors and provid-ing on-farm suitable nesting and floral resource habitats for propagation and conservation are discussed.