HOST RESISTANCE TO THE FIR ENGRAVER BEETLE, SCOLYTUS VENTRALIS (COLEOPTERA: SCOLYTIDAE): 2. REPELLENCY OF ABIES GRANDIS RESINS AND SOME MONOTERPENES

Abstract

AbstractCortical blister and wound reaction resin vapors from Abies grandis, and some of their monoterpene fractions, were quantitatively bioassayed for attractiveness and repellency to the fir engraver beetle, Scolytus ventralis. All were found to be repellent.Quantitative differences between liquid resins and vapors were examined. Wound reaction resin vapors contained higher percentages of the more repellent monoterpenes than cortical blister resin vapors. It is hypothesized that α-pinene is the most important monoterpene in the insects’ perception of a resistant host.