Bjorn F. Hrutfiord

Monoterpenes in sitka spruce: Within tree and seasonal variation

Abstract The composition of oils from needles and cortex of Sitka spruce is unique. Cortex oil is essentially all monoterpene hydrocarbons, while needle oil may be up to 50% oxygenated monoterpenes. Very wide seasonal variations in composition occur in needle oil in young tissue. At bud burst, the oil is > 95% myrcene; this drops to about 40% at the end of summer. The oxygenated terpenes camphor and piperitone develop to about 20% each in concentration during the growing season.

Dendroctonus pseudotsugae: A Hypothesis Regarding Its Primary Attractant

The Douglas-fir beetle is attracted to α-pinene but repelled by β-pinene. Attacks on standing trees are related to the content of α- or β-pinene in the tree; this correlation suggests that volatile oils may be the stimuli initially attracting the insect to the Douglas fir.

Essential oil of Conyza canadensis

Abstract GC/MS of the essential oil from horseweed ( Conyza canadensis ) was used to identify three matricaria ester isomers, lachnophylum ester, and two rela

Germacrone, a sesquiterpene repellent to obscure root weevil from Rhododendron edgeworthii.

Abstract A steam volatile fraction from Rhododendron edgeworthii leaves inhibited obscure root weevil ( Sciopithes obscurus ) feeding on sucrose-treated membrane filters. The most prominent component in this fraction was the sesquiterpene germacrone. Germacrone was found to be an obscure root weevil repellent.

Composition of essential oils of some lipidote Rhododendrons

Abstract Essential oils from leaves of 43 species of Rhododendron comprising 21 subsections were generally complex, and contained a number of compounds that were not identified. Caryophyllene, humulene, and one or more eudesmol isomers were the most commonly identified constituents. α-Pinene was the major component in eight of the oils, and germacrone was the major component in five of the oils. Monoterpenes were the major components of the oils in eight of the 12 species of subsection Triflora that were examined. Sesquiterpenes were major components in about 80% of the other 31 species.