Iowa State University Veterinarian Records, RS 22/6/0/9, University Archives, Special Collections Department, Iowa State University, http://www.add.lib.iastate.edu/spcl/arch/rgrp/22-6-0-9.html
Cattle producers seem to be in love with the latest type of fly control technique - insecticidal ear tags. Anyone driving along the back roads is treated to the site of cattle herds sporting the brightly colored plastic ear devices. A closer look reveals that few flies annoy animals protected in this manner.
Iowa State University Veterinarian
"Insecticidal Ear Tags: Fly Control That Works,"
Iowa State University Veterinarian: Vol. 45
, Article 11.
Available at: http://lib.dr.iastate.edu/iowastate_veterinarian/vol45/iss2/11