SummaryThroughout the summer of 1981 honeybees were observed feeding on honeydew exudate from swollen lesions, probably bacterially induced, on the undersides of twigs of Gambel's oak (Quercus gambelii), growing near Colorado Springs, CO., USA. The honeydew appeared to be a phloem derivative, as judged by its chemical composition. Sucrose, glucose and fructose were present, as well as all 20 essential amino acids, proteins, and abundant phenols.