Corn pollen deposition on milkweeds in and near cornfields
Authors: Pleasants, J.M., Hellmich, R.L., Dively, G.P., Sears, M.K., Stanley-Horn, D.E., Mattila, H.R., Foster, J.E., Clark, T.L., Jones, G.D.
Journal, Volume, Year: Proceedings of the National Academy of Sciences, volume 98:11919-11924, 2001
Studies were conducted in Iowa, Minnesota, Wisconsin, Ontario, and Maryland to determine the density of corn pollen on leaves of milkweed plants inside and outside of cornfields. Pollen densities were highest inside cornfields and were progressively lower from the edge of the field outward. Leaves on the upper portion of the milkweed plants, where monarch larvae often feed, only had 30-50% of the pollen densities of middle leaves.
This study gives a representative picture of pollen densities occurring on milkweed plants in a natural environment. This information is useful for conducting laboratory and field studies.