The Cornell team said the risks to monarchs could be heightened because the butterflies migrate northward through the U.S. Corn Belt from their winter homes in Mexico during the springmonths, when corn pollen is thickest.
The wall of glass on one side of the library, combined with its geographic exposition and the density of students in the small facilities turned it into a sauna for half the day during the springmonths (which were also the exam months, when the libraries were most in demand).