• Trial, Henry, Jr.
  University of Maine Graduate School
  

A naturally occurring anthraquinone, emodin, was evaluated as a possible chemical feeding deterrent to herbivorous insects. The presence of emodin in the leaves of alder-leaved buckthorn, Rhamnus alnifolia, was confirmed and quantified using thin layer chromatography. Leaves early in development were found to contain more emodin than mature leaves. Powdered alder-leaved buckthorn leaves, commercially prepared emodin, and emodin extracted from alder-leaved buckthorn leaves when added to artificial diet were all found to decrease frass production, slow development, and increase mortality in larvae of the gypsy moth, Prothetria dispar, compared to controls.