Bee community interactions: observations in foraging on commercial sunflowers

Authors: Yoshimura Ferguso, Mary; Prasifka, Jarrad

Submitted to: National Entomological Society of America Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 10/29/2021
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Pollinators are an essential component of commercial sunflower production and their services are necessary to maximize yields. Sunflowers are predominantly grown in North and South Dakota where pollination services rely almost entirely on unmanaged, native bees. Research on how tongue length correlates with floret depth indicates some flexibility by the bees, but the majority of foraging is within 1-1.5 times the functional tongue length. Because the tongue lengths of the bees within the pollinator community overlap, there is the possibility for competition between foragers for resources. This may result in negative effects for both the pollinators and for the plant. This research sought to better understand inter- and intra-specific interactions between bee pollinators in cultivated sunflower throughout the growing season by observing and quantifying behavior. To do so, three sunflower lines were grown under field conditions with known floret lengths of 8-10mm. Lines were planted at three different times in 2020-early, mid, and late season and two times in 2021-early and late, to capture the intervals at which different native bee species are actively foraging. Cameras were used to capture a 4-hour time period from 9:30am-1:30pm for each sunflower line during bloom. Sunflower lines were planted so bloom occurs when community composition is most different: more specialized, smaller bees early in the season and more generalist, larger-bodied bees later. Videos were analyzed to determine the types of behaviors, how long they occurred, and if various behaviors or interactions resulted in cessation or continuation of foraging on the same head.