Wild bee pollinators foraging in peanut and cotton adjacent to native wildflower strips

Authors: Olson, Dawn; GIBBS, JASON - University Of Manitoba; SCHMIDT, JASON - University Of Georgia

Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/23/2021
Publication Date: 9/23/2021
Citation: Olson, D.M., Gibbs, J., Schmidt, J. 2021. Wild bee pollinators foraging in peanut and cotton adjacent to native wildflower strips. Florida Entomologist. 104(3):165-172. https://doi.org/10.1653/024.104.0304.
DOI: https://doi.org/10.1653/024.104.0304

Interpretive Summary: Wild bees are major contributors to pollination of economically important crops. But widespread habitat conversion to agriculture is associated with declines in wild bee abundance and biodiversity. A growing number of studies have investigated the incorporation of a variety of flower species in agroecosystems to augment resource and habitat availability to wild bees and pollination of nearby crops. Here, we investigated if established wildflower buffers promote pollinator abundance and the pollination of nearby peanut and cotton. We used bee bowls to capture bees, and we identified the pollen on the bees captured in these crops. The density of bees with only Gaillardia pulchella and both G. pulchella and peanut pollen was highest on 6 July, when, proportionally, 52% of bees bore only G. pulchella pollen and 48% of bees bore both G. pulchella and peanut pollen. The density of bees with wildflower buffer pollen in cotton was highest on 2 July, when, proportionally, 53% of bees bore Monarda citriodora pollen, 12% bore G. pulchella pollen,19% bore Rudbeckia hirta pollen, and 26% of bees bore one or more wildflower buffer pollen and cotton pollen. These results indicate that the wildflower buffers had provided pollinators and potential pollination to these crops early in the season. By studying the actual flow of pollen between crops and wildflower buffers, we show the promise of increased pollination and ways to extend bloom period of floral resources that strengthen pollination services in the southeastern US.

Technical Abstract: Because of the loss of natural and semi-natural habitat in agricultural settings, wild bee declines in abundance and biodiversity are now widespread. We investigated the potential of previously established native wildflower buffers to increase bee abundance and promote pollination of nearby peanut and cotton. We also estimated the nectar and pollen availability in the flowers over time. We created a pollen library for the pollen of peanut, cotton and the wildflower species, utilized bee bowls to capture bees in the peanut and cotton, removed the pollen from the bees and identified the bee species and the pollen species found. Bees with wildflower and crop pollen were found in both crops early in the season. Monarda citriodora pollen was found on 53% of the bees captured in cotton, and the disc flowers of the two composite flower species (Gaillardia pulchella and Rudbeckia hirta) were very slow in opening which contributed to the lower percentage of bees in both crops with their pollen. A total of 91% of the bees captured in cotton had unidentified flower pollen indicating that they had foraged on other flowers on the experimental farm. Increasing the biodiversity of wildflowers in the buffers is needed to ensure resource availability to bees over time.