TWO PHEROMONES OF CONIFEROPHAGOUS BARK BEETLES OCCURIN THE BARK OF NON-HOST ANGIOSPERM TREES.

Dezene P. W. Huber, Regine Gries, John H. Borden, and Harold D. Pierce,Jr.
Centre for Pest Management, Department of Biological Sciences, SimonFraser University, Burnaby, BC, Canada, V5A 1S6.

Volatiles from fresh bark of black cottonwood, Populus balsamifera,paper birch, Betula papyrifera, bigleaf maple, Acer macrophyllum,quaking aspen, Populus tremuloides, Sitka alder, Alnus sinuata,and red alder, Alnus rubra were collected on Porapak Q, and subjectedto coupled gas chromatographic-electroantennographic analysis utilizingthe antennae of the Douglas-fir beetle, Dendroctonus pseudotsugae. Coupled gas chromatographic-mass spectroscopic analysis was used to identifytwo of the antennally-active compounds as frontalin (in red and Sitka alder)and conophthorin (in Sitka alder, paper birch, black cottonwood, quakingaspen and bigleaf maple). Our results pose major questions regardingthe evolution and ecological role of these semiochemicals. They alsosuggest that comparative studies on the biosynthetic pathways for thesecompounds would be of considerable evolutionary interest.