Using Microscopy to Determine the Extent to Which Soybean (Glycine max) Is Utilized by Honey Bees (Apis Mellifera) in Agroecosystems

Jack Omori
Undergraduate (Entomology)
Dr. Reed Johnson
Environment and Natural Resources

Considering the abundance of agricultural lands in central Ohio, and Ohio's role as one of the country's leading soybean (Glycine max) producers, the possibility of increased soybean yields due to honey bee (Apis mellifera) pollination could benefit farmers, and the honey produced from this crop could benefit beekeepers. However, research on honey bee preferences for soybeans compared to common weeds and other flowering crops found in the agroecosystem is limited. Using microscopy, honey was examined to determine the number of lycopodium spores, added as an internal standard, compared to the number of pollen grains from soybean, sweet clover (Melilotus spp.), sanicle (Sanicula spp.), basswood (Tilia spp.), and clover (Trifolium spp.) in honey samples that were collected before and after the soybean bloom in late July, 2019. Honey samples were categorized into two groups ("Before Soybean Bloom" and "After Soybean Bloom") and a one way ANOVA test was conducted. The results of the one way ANOVA showed significant differences between the number of soybean (p = <0.001), sweet clover (p = 0.002), basswood (p = 0.019), and clover (p = 0.002) pollen grains present between the two groups. While sweet clover, clover, and basswood pollen grains are present in samples taken after the soybean bloom, their average number is significantly lower, indicating a foraging preference for soybeans when they are available. This is possibly explained by how abundant soybeans are in the foraging range compared to the other species of interest. Another explanation is that basswood, and potentially clover, were no longer blooming by the time the soybean bloom occurred.