I'd be surprised if the pollen collected from pollen traps would still be useable for pollination of sunflowers. Bees typically use regurgitated nectar to moisten pollen for packing it into corbiculae. This might have a negative effect on viability, and would probably make it difficult to restore the pollen to a form useful for pollination. Not a lot is known about the lifetime of viable pollen grains, but in some species it's measured in hours, so unless the pollen were collected immediately from the trap it might not still be viable. If you want to test pollen grains for viability you might look at the book 'Techniques for Pollination Biologists', by C. A. Kearns and D. W. Inouye. University Press of Colorado, Niwot, CO. Dr. David W. Inouye Dept. of Zoology, University of Maryland, College Park, MD 20742 E-mail: [log in to unmask] Phone: 301-405-6946 FAX: 301-314-9358