Host-Tree Chemistry Affecting Colonization in Bark Beetles

Interruption of aggregation pheromone in Ips typographus (L.) (Col. Scolytidae) by non‐host bark volatiles

“…Analysis of the key decisions that bark beetles must make during the process of host selection (Borden, 1997;Schlyter & Birgersson, 1999) reveals that the following negative signals may be exploited in potential tactics for control of conifer bark beetles: (i) volatiles indicating the unsuitable host trees, such as verbenone (Vn) from host trees fully colonized by conspecific species, 4-allylanisole and monoterpenes from resistant hosts (Hayne et al, 1994;Byers et al, 2000;Erbilgin & Raffa, 2000), and other synomones from heterospecific bark beetles (Byers, 1995;Borden, 1997); (ii) specific bark volatiles signalling the nonhost angiosperm species (Borden et al, 1998;Schlyter & Birgersson, 1999;Huber, 2001;; or (iii) common green leaf volatiles (GLVs), especially the C 6 -alcohols emitted at high levels from leaves (and to a less extent from bark) of angiosperm trees/plants representing the nonhost habitats (Dickens et al, 1991(Dickens et al, , 1992aHuber, 2001;). Due to the inconsistent effects of Vn and 4-allylanisole, and the expensiveness of heterospecific synomones (Borden, 1997), recent studies have focused on inexpensive GLVs and other nonhost volatiles (NHVs) from the intact angiosperm trees.…”

Host Selection in Tomicus piniperda L.: Composition of Monoterpene Hydrocarbons in Relation to Attack Frequency in the Shoot Feeding Phase

“…T. piniperda is strongly attracted by the host monoterpenes released through an injury on the tree or through the holes made by the pioneer beetles in the trunk. This can in fact induce a mass attack comparable to that induced by the aggregation pheromones in other species (Lå ngström et al, 1992;Byers, 1995).…”

“…The sensitivity towards different kinds of monoterpenes differs within populations of bark beetles, depending on whether the composition of the terpenes represents their respective host trees or not (Byers, 1995). T. piniperda is strongly attracted by the host monoterpenes released through an injury on the tree or through the holes made by the pioneer beetles in the trunk.…”

Bark Beetles Control in Forests of Northern Spain

“…It is likely that each species of tree has coevolved chemicals to defend against the selection pressures of bark beetles and other insects (Berryman et al, 1985;Byers, 1995). Plant chemicals can be attractive, repellent, toxic or nutritious to bark beetles and have effects on: (1) finding and accepting the host tree (selection and suitability); (2) feeding stimulation and deterrence; (3) host resistance; (4) pheromone biosynthesis and communication; and (5) attraction of predators, parasites and competitors of bark beetles (Byers, 2004).…”