Location: Sunflower Improvement Research
Project Number: 3060-21000-047-012-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Aug 1, 2022
End Date: Jul 31, 2025
Objective:
(1) Assess foraging of sunflower specialist pollinators (e.g., Melissodes agilis, Melissodes trinodis) in North Dakota on plants other than sunflowers, and (2) Determine whether foraging differs for bee species, sexes, and bees collected from field edges or interiors.
Approach:
Cultivated sunflowers depend on pollinators to make the crop profitable. In the primary sunflower-producing states (North Dakota, South Dakota), honey bee hives are often located near sunflowers, but most of the pollination of the crop is performed by bees that are specialists on sunflowers and other Asteraceae. Bees in the genus Melissodes are among the most common and most effective sunflower pollinators in the Upper Midwest. However, sunflower bloom in a field can be brief relative to the adult life of Melissodes spp. and research on related bees in South America suggests these pollinators may rely substantially on pollen and nectar found outside of sunflower fields. Also, because these bees are relatively small, the distance they can fly to collect nectar and pollen is short. To determine how Melissodes spp. survive in a landscape where their primary food resource (sunflowers) is only briefly available, adult bees will be assessed for foraging on other plant species by DNA-based identification of pollen on their bodies. Pollen removed from Melissodes spp. foraging on cultivated sunflowers will evaluated using sequencing of reliable markers (e.g., ITS [internal transcribed spacer] or trnL) for which plant sequence databases already exist. The number and identity of plant pollens found will be compared across bee species, sexes, and locations (field edge versus interior). The results will be important in understanding potential ways to support the abundance and health of these important sunflower pollinators.
