Antennae of Cryptorhynchus lapathi (Coleoptera: Curculionidae) detect two pheromone components of coniferophagous bark beetles in the stems of Salix sitchensis and Salix scouleriana (Salicaceae)

2005 ◽  
Vol 137 (6) ◽  
pp. 716-718 ◽  
Author(s):  
Cynthia L. Broberg ◽  
John H. Borden ◽  
Regine Gries

Several scolytid beetles (Coleoptera: Scolytidae) produce conophthorin, (E)-7-methyl-1,6-dioxaspiro[4.5]decane, and use it as an aggregation or antiaggregation pheromone or competition-mediating synomone (Francke et al. 1979; Kohnle et al. 1992; Birgersson et al. 1995; Pierce et al. 1995; de Groot et al. 1998; Dallara et al. 2000; Rappaport et al. 2000). Predators or associates of these beetles may use conophthorin as a host- or habitat-finding kairomone (Kohnle et al. 1992). Other conifer-infesting scolytid and predator species use chalcogran, 2-ethyl-1,6-dioxaspiro[4.4]nonane, a semiochemical with functions similar to those of conophthorin (Francke et al. 1977; Heuer and Vité 1984; Baader 1989; Byers 1993; Byers et al. 1989, 2000).

1992 ◽  
Vol 22 (4) ◽  
pp. 436-441 ◽  
Author(s):  
Patrick J. Shea ◽  
Mark D. McGregor ◽  
Gary E. Daterman

Mountain pine beetle, Dendroctonusponderosae Hopkins, is the primary pest affecting lodgepole pine, Pinuscontorta var. latifolia Engelm., ecosystems in western North America. In 1988, aerial treatments of the antiaggregation pheromone, verbenone, were applied to lodgepole pine stands infested with mountain pine beetle in northwestern Montana. The pheromone was formulated by PHERO TECH Inc. in controlled-release, cylindrical 5 × 5 mm plastic beads and applied without benefit of a sticker at the rate of 54 g verbenone per hectare. There were significantly fewer successfully attacked trees on the treated plots, as evidenced by (i) a fourfold greater incidence of current-year attacked trees per hectare in the untreated check plots and (ii) the significantly lower (α = 0.05) ratio of 1988:1987 attacked trees in the treated plots. Further, the number of trees per hectare resisting attacks (as reflected by number of trees pitching out bark beetles) was higher (α = 0.05) in the treated plots. More pitch outs occurred in treated plots presumably because avoidance of verbenone by beetles reduced the number of beetles below that needed to overcome the natural resistance of attacked trees.


2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
John A. Byers

Previous studies and data presented here suggest that odors from healthy host Scotch pine (Pinus sylvestris) and nonhost Norway spruce (Picea abies), as well as major monoterpenes of these trees at natural release rates, significantly reduce the attraction of flying bark beetles,Pityogenes bidentatus, of both sexes to their aggregation pheromone components grandisol andcis-verbenol in the field, as tested by slow rotation of trap pairs. In contrast,P. bidentatusmales and females walking in an open-arena olfactometer in the laboratory did not avoid monoterpene vapors at release rates spanning several orders of magnitude in combination with aggregation pheromone. The bark beetle may avoid monoterpenes when flying as a mechanism for avoiding nonhost species, vigorous and thus unsuitable host trees, as well as harmful resinous areas of hosts. Inhibition of this flight avoidance response in beetles after landing would allow them to initiate, or to find and enter, gallery holes with high monoterpene vapor concentrations in order to feed and reproduce.


2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Qing-He Zhang ◽  
Fredrik Schlyter ◽  
Göran Birgersson

Volatiles from bark of aspen,Populus tremulaL. and two species of birch: silver birch (Betula pendulaRoth.) and common birch (B. pubescensEhrh.), were collected by direct solvent extraction and aeration of both newly cut bark chips and undamaged stems in June 1998 and subjected to GC-MS analysis. The results showed the presence of 2-methyl-3-buten-2-ol (MB), one of the two principal aggregation pheromone components of the spruce bark beetle,Ips typographus, in bark extraction samples of all the three deciduous tree species tested. In addition, one more oxygenated hemiterpene, 3-methyl-3-buten-2-one, and (E)-3-penten-2-ol were also found in the bark extracts. Only trace amounts of MB were detected in some aeration samples of the fresh bark chips, and no MB was found from the aeration samples of undamaged stems at detectable levels. The occurrence of this compound was also confirmed in the bark of four exotic birch species:B. albosinensisSchneid.,B. ermaniiCham.,B. jacquemontiiSpach, andB. maximowiczianaRegel, but not yet in the European pines/spruces and the common yeasts. Our results raise major questions regarding the evolution, the tropospheric chemistry, and the ecological role of this hemiterpene alcohol. They also suggest that comparative studies on the biosynthetic pathways for MB in different sources would be of considerably evolutionary interest.


2020 ◽  
Vol 144 (7-8) ◽  
pp. 350-350
Author(s):  
Milan Pernek ◽  
Marta Kovač ◽  
Nikola Lacković

In the Aleppo pine forests at the Croatian Mediterranean in 2017, a Mediterranean bark beetle (Orthotomicus erosus) appeared in population densities that had not been recorded before and until then was not considered a significant pest in that area. Natural enemies are not able to follow a sudden increase of the bark beetle population, which results in rapid increase of drying trees. As a part of the suppression of the Mediterranean bark beetle in 2018, pheromone traps have been installed in Croatia for monitoring purposes. Although there are multiple options for applying different types of traps and pheromone preparations for the Mediterranean bark beetle, so far the differences in catches of different types of traps and their selectivity have not been investigated. In 2019, 40 pheromone traps were placed in the Forest Park ​​Marjan (Split) on 196 ha of forest area. A pairs of pheromone preparations Pheroprax and Erosowit were compared, a system of three traps (Triplet) with a single flight barrier trap as well as the modified wet flight barrier trap with a regular flight barrier trap. In addition to the average number of catches in pheromone traps, particular attention was given to selectivity. Two predator species Tanasimus formicarius and Temnochila caerulea were found in traps, with T. formicarius in insignificant quantities relative to T. caerulea. The results indicate that Erosowit exhibits significantly higher catches compared to Pheroprax and is significantly more selective. Pheroprax has a very high catches of T. caerulea predators and is not recommended for practical use. The Triplet had only slightly better catches compared to the single flight barrier trap, but also showed slightly better selectivity. The Triplet did not show the expected effect due to the amount of the catch, which was slightly higher than in the single trap, but not significantly in order to recommend their use. The wet flight barrier trap turned out not to be satisfactory as it does not produce significantly higher catches than a regular flight barrier trap, and is twice less selective. Given the additional costs (trap adaptation, fluid that needs to be changed, slower collection), this trap type is not recommended for use. Comparing the results of the catch in 2019, the number of bark beetles was found to be almost 5 times lower than in 2018.


1989 ◽  
Vol 19 (10) ◽  
pp. 1275-1282 ◽  
Author(s):  
D. W. A. Hunt ◽  
J. H. Borden ◽  
B. S. Lindgren ◽  
G. Gries

The monoterpene α-pinene, a major component of the terpene composition of Pinus spp., has been reported to act as a host-produced kairomone for a variety of bark beetle species, including the mountain pine beetle, Dendroctonusponderosae Hopkins. However, our experiments indicate that α-pinene autoxidizes under normal temperature and atmospheric conditions to form significant quantities of trans-verbenol, an aggregation pheromone for many species of bark beetles. The quantities of α-pinene present in the resin that can flow from small wounds in pine trees appear to be sufficient to produce trans-verbenol at rates similar to those by female beetles that are actively synthesizing the compound.trans-Verbenol can then autoxidize rapidly to form verbenone, with the content of this compound reaching 8% within 13 weeks of exposure to air. Verbenone is often used by scolytids as an antiaggregation pheromone. Approximately 1.9% of the trans-verbenol and 2.7% of the verbenone found in Porapak Q aerations of phloem with boring spruce beetle, Dendroctonusrufipennis (Kirby), females, as well as 0.8% of the trans-verbenol and 0.8% of the verbenone found in aerations of phloem with boring D. ponderosae females, was due to the autoxidation of α-pinene and (or) the release of oxygenated compounds found in the phloem before bark beetle attack. The natural interconversion of α-pinene, trans-verbenol, and verbenone under ambient conditions suggests that many experiments involving the behavioral activity of these compounds require re-evaluation.


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