01766nas a2200169   4500008004500000245020300045210006900248260001000317300001000327490000600337520102200343653002101365100002101386700002501407700002901432856013501461       2008                        Engldsh  00aInfestation by a Nalepella species induces emissions of alpha - and beta -farnesenes, (-)-linalool and aromatic compounds in Norway spruce clones of different susceptibility to the large pine weevil0 aInfestation by a Nalepella species induces emissions of alpha an  cMarch  a31-410 v23 aThe emissions of spruce grafts (Picea abies), caused by infestation of an acarid species of the genus Nalepella were investigated. Volatiles of three clones, both healthy and infested, with different susceptibility to the large pine weevil Hylobius abietis were collected by solid phase micro extraction (SPME) and analyzed by gas chromatograph coupled to mass-spectrometry (GC-MS). In addition, enantiomers of the main chiral compounds were separated by a two dimensional-gas chromatograph (2DGC). In the characteristic flower-like fragrances emitted by the infested grafts large amounts of E-[beta]-farnesene, E,E-[alpha]-farnesene, (-)-linalool, methyl salicylate and minute amounts of benzyl alcohol, E-anethole, methyl benzoate, neral and geranial were found. All together, these compounds could explain the characteristic scent emitted by the infested seedlings. Large differences in the emissions of E-[beta]- farnesene, E,E-[alpha]-farnesene and methyl salicylate were found between but not within the clones.10aHylobius abietis1 aKannaste, Astrid1 aVongvanich, Namphung1 aBorg-Karlson, Anna-Karin  uhttps://weevil.myspecies.info/infestation-nalepella-species-induces-emissions-alpha-and-beta-farnesenes-linalool-and-aromatic-comp02153nas a2200193   4500008004100000020001400041245013500055210006900190260000800259300001200267490000800279520143600287653002001723100001401743700002901757700002001786700001801806856013501824       2011                        eng d  a0029-854900aHost resistance elicited by methyl jasmonate reduces emission of aggregation pheromones by the spruce bark beetle, Ips typographus0 aHost resistance elicited by methyl jasmonate reduces emission of  cNov  a691-6990 v1673 aWe treated Norway spruce (Picea abies) stems with methyl jasmonate (MeJA) to determine possible quantitative and qualitative effects of induced tree defenses on pheromone emission by the spruce bark beetle Ips typographus. We measured the amounts of 2-methyl-3-buten-2-ol and (S)-cis-verbenol, the two main components of the beetle's aggregation pheromone, released from beetle entrance holes, along with phloem terpene content and beetle performance in MeJA-treated and untreated Norway spruce logs. As expected, phloem terpene levels were higher and beetle tunnel length was shorter (an indication of poor performance) in MeJA-treated logs relative to untreated logs. Parallel to the higher phloem terpene content and poorer beetle performance, beetles in MeJA-treated logs released significantly less 2-methyl-3-buten-2-ol and (S)-cis-verbenol, and the ratio between the two pheromone components was significantly altered. These results suggest that host resistance elicited by MeJA application reduces pheromone emission by I. typographus and alters the critical ratio between the two main pheromone components needed to elicit aggregation. The results also provide a mechanistic explanation for the reduced performance and attractivity observed in earlier studies when bark beetles colonize trees with elicited host defenses, and extend our understanding of the ecological functions of conifer resistance against bark beetles.10aIps typographus1 aZhao, Tao1 aBorg-Karlson, Anna-Karin1 aErbilgin, Nadir1 aKrokene, Paal  uhttps://weevil.myspecies.info/host-resistance-elicited-methyl-jasmonate-reduces-emission-aggregation-pheromones-spruce-bark-beetle