VOLATILES INVOLVED IN THE NONHOST REJECTION OF FRAXINUS-PENNSYLVANICABY LYMANTRIA-DISPAR LARVAE

Volatiles from green ash foliage or ambient air was trapped by Super Q and their chemical identities determined by GC-MS analysis. Effects o f the whole mixture and individual chemical components of green ash vo latiles on gypsy moth larval (GML) locomotory behavior were assayed in a T-tube arena. Green ash volatiles (treatment) proved significantly repellent to GML as compared to Super Q trappings of volatiles from th e ambient air (control). Such observed effects were due to the combine d repellencies of linalool, methyl salicylate, and farnesenes; however , the relatively major component, trans-ocimene, proved to be nonrepel lent. The significance of such volatiles in GML orientation and host/n onhost decision is discussed.