Spruce beetle rufipennis

B) Western balsam bark beetle, Dryocoetes confusus formation of endo-brevicomin [(1 F ,5S,7S)-7-ethyl-5-methyl-6,8-dioxabicyclo[3.2.1 ]octane] from ( )-6-nonen-2-one (Vanderwel et a/., 1992a) (C) Spruce beetle, Dendroctonus rufipennis formation of frontalin [(1S, 5fl)-(-)-1,5-dimethyl-6,8-dioxabicyclo[3.2.1]octane] from 6-methyl-6-hepten-2-one (Perez ef a/., 1996 Francke etai, 1995 Francke and Schulz, 1999) (D) European elm bark beetle, Scolytus multistriatus hypothetical formation of oc-multistriatin [(1 S,2F ,4S,5F )-(-)-2,4-dimethyl-5-ethyl-6,8-dioxabicyclo[3.2.1]octane] from 4,6-dimethyl-7-octen-3-one (Francke and Schulz, 1999) and E The colored... 

A second example is the spruce beetle, Dendroctonus rufipennis (Kirby) (Coleoptera Scolytidae), a major cause of mortality in mature spruce stands. Gries et al. (1992) found that the terpene verbenene (31 in Figure 19.5), was emitted from the beetles, predominantly from females, and concluded that it is a pheromone component. The oxygenated compounds seudenol, frontalin, and l-methyl-cyclohex-2-en-l-ol, were previously identified as pheromone components in this species. Attraction to verbenene alone was demonstrated in field traps, and it enhanced captures to the other pheromone components. The absolute configuration of verbenene has not been investigated. 

Fig. 4.6 Former spruce forest converted to deciduous (light colored) stand, primarily birch, by Dendroctonus rufipennis on Kenai Pen., Alaska. These stands were naturally occurring spruce monocultures, in which near total mortality occurred within approximately three years. Spruce trees in these forests typically range from several meters above water levels to tree line. Note dark trees are young spruces that were too small for spruce beetle during the outbreak. These trees will ultimately replace birch and reconvert to a spruce forest. Outbreak by spruce beetle will eventually follow when favorable conditions occur. Photo by Kirsten Haberkem.

Green leaf volatiles, including (E)-2-hexenal, disrupt responses by the spruce beetle, Dendroctonus rufipennis, and the western pine beetle, Dendroctonus brevicomis, to attractant-baited traps. 

Bowers W. W. and Borden J. H. (1990) Evidence for a male-produced aggregation pheromone in the four-eyed spruce bark beetle, Polygraphus rufipennis (Kirby) (Col., Scolytidae). J. Appl. Entomol. 110, 292-299. 

Sahota T. S. and Farris S. H. (1980) Inhibition of flight muscle degradation by precocene II in the spruce bark beetle, Dendroctonus rufipennis (Kirby) (Coleoptera Scolytidae). Can. J. Zool. 58, 378-381. 

We considered three questions 1) Do populations colonize trees of different physiological conditions during endemic versus eruptive phases 2) Are behavioral responses to phytochemieals heritable 3) Do beetles from eruptive vs. endemie populations differ in responses to phytochemieals We eondueted this researeh in 29 sites in three regions Alaska, Yukon Territory in Canada, and Utah. The 15 eruptive and 14 endemic sites were evenly distributed among the 3 regions, all sites were nearly pure spruce monoeultures separated by more than the effeetive dispersal distance of D. rufipennis, and contained trees that did not differ in monoterpene concentration or stem diameter. 

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