Mason Bees (IMAGE) University of California - Riverside Caption The photo shows native mason bees in the UCR Entomology Research Museum. Most of these specimens are from the 1930s. Credit UCR Entomology Research Museum. Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.