Preventative measures: Quarantine restrictions in northern China prevent the unauthorised movement of infested material including trees, logs and wood products (Yan et al. 2005). Cargo is currently checked by hand. To avoid over-sights improved equipment and methods are needed (Yang 1993, in Liu & Dai 2006).
Pine plots in China are inspected in the summer and the fall for indicators of D. valens attack, such as the presence of pitch tubes or boring material (Yan et al. 2005). Flight traps, funnel traps and pitfall traps are all used to monitor beetle numbers (Erbilgin Nadir & Raffa 2002). Lower stem flight traps have been shown to catch relatively high numbers of D. valens (Yan et al. 2005).
Chemical: Bark beetles are good candidates for semiochemical-based control methods (Borden 1997, in Rappaport Owen & Stein 2001). The use of ecologically-selective semiochemicals are environmentally friendly and non-toxic (Carmona Undated). Research on bark beetle response to pine host volatiles and beetle pheromones in China and North America is on-going. Anti-aggregation pheromones such as verbenone repel red turpentine beetles. Verbenone acts as a chemical message to D. valens that host food resources are limited. Release rates of the pheromone must be carefully controlled as low release rates of verbenone will actually increase D. valens response to host attractant molecules.Pine monoterpenes are highly attractive to bark beetles (Liu & Dai 2006) and have applications in the monitoring and trapping of beetles. (+)-3-carene and the standard North American D. valens lure of a 1:1:1 ratio of (+) alpha-pinene & beta-pinene (+)-3-carene are effective in attracting D. valens (Erbilgin et al. 2007). The standard lure was used in a mass-trapping program in the Guandi Mountains (west of Shanxi province, China). The proportion of infested forest decreased by 64.4% and the average number of attacks per tree decreased by 59.2% (Guo et al. 2003, in Yan et al. 2005). Ethanol attracts various scolytid beetles including D. valens when released at relatively low or medium concentrations (Yan et al. 2005). A 1:1 ration of ethanol:turpentine captured 60 times more D. valens than turpentine alone (Klepzig et al. 1991, in Yan et al. 2005). 4-Allylanisole (4AA), released by some pines, may prove useful in protecting high-value logs or individual trees by it ability to reduce bark beetle attraction to ethanol (in combination with alpha-pinene & beta-pinene) (Jospeh et al. 2001).
Insecticides: Fumigation or injection of beetle galleries or spraying of basal tree trunks with insecticides may result in 90 to 98% beetle mortality (Shanxi Forestry Bureau Unpub. Data). Fumigation is costly and difficult and is not effective at controlling beetle populations over large areas. It can result in environmental contamination and decreased natural enemy populations.
Biological: Research from the Université Libre de Bruxelles showed that Rhizophagus grandis is able to successfully complete its life-cycle with D. valens. R. grandis responds to attractants produced by D. valens, enters D. valens galleries and oviposits a relatively high number of eggs. (LUBIES 2004). Steinernema ceratophorum, a nematode isolated from Jilin province in northeast China, has also produced high infection rates of D. valens larva, causing a larval mortality rate of 90% (Jian et al. 2002).
Please follow this link for detailed information on the management of the Red turpentine beetle (Dendroctonus valens).
Location Specific Management Information
Williams and colleagues (2008) investigated abundance and flight periodicity of bark beetles, including Dendroctonus valens, among three different elevation bands of ponderosa pine (Pinus ponderosa) forest in north-central Arizona (USA) for three years using pheromone-baited Lindgren funnel traps. Elevation bands were: 1600 to 1736 meters, 2058 to 2230 meters and 2505 to 2651 meters. D. valens was found at all three elevations, however, a greater abundance of D. valens was observed at the high elevation zone (2505 to 2651 meters), which is higher than the favored elevation interval (2100 to 2500 meters) for D. valens in Mexico (Salinas-Moreno et al. 2004, in Williams et al. 2008). At all elevations D. valens flight activity occurred from early April to late October with peak flight activity in May and with activity tapering off by August. This period of flight activity is similar to the reported flight period in its northern range (Wood 1982 in Williams et al. 2008). D. valens has one generation in two years in the coldest parts of its range, but may have two to three generations per year in warmer climates (Smith 1971 Williams et al. 2008).
The importance of synchronised bark beetle attacks is poorly understood. In southwest North America ponderosa pine forests D. adjunctus and D. valens often occur from the base of the tree to half a meter in height. Beetle success in killing a vigorous host by a synchronised attack could offset costs of inter-specific competition. Alternatively, niche overlap of two or more species may prevent an individual species from ever dominating utilisation of the resource and reaching outbreak levels. Inter-specific competition for resources may hold invasive species in check in their native range. This lack of inter-specific competition in introduced areas may explain the severity of outbreak of D. valens in northern Chinese forests. Sakai and colleagues (2001, in Erbilgin et al. 2007) reported that the reasons underlying the greater tree mortality in China could include a lack of evolutionary adaptation to this new insect-host (Dendroctonus valens-Pinus tabulaeformis) association.
Wallin and colleagues (2008) found that the thinning of ponderosa pine Pinus ponderosa near Flagstaff (Arizona, USA) decreased the percentage of trees with bark beetle infestations. Beetle attacks were induced by beetle community response to a Dendroctonus brevicomis pheromone; the D. brevicomis pheromone attracts several bark beetle species. The positive affect of restoration treatments on tree resistance may be due to the underlying stimulation of resin defenses. Thinning treatments have been reported to increase production of carbon-based defenses such as resin in some studies (Kolb et al. 1998, Feeney et al. 1998, McDowell et al. 2007, in Wallin et al. 2008). These findings along with those of the authors suggest that thinning reduces resource competition among trees and hence, tree stress, and increases carbon allocation to resin defenses in the tree. Resin flow after phloem wounding was greater in restoration treatments than in control in the first and second year after treatment. The authors found a negative correlation between resin volume and the number of D. valens brood which emerged from the bole.
In Carmel (CBD and City Zone), beetle infestations are removed from the tree and infested and adjacent trees sprayed with carbaryl (Sevin). If the beetle attacks are too numerous only spraying is done (G. Kelly Pers. Comm. 1988, in Nowak & McBride 1992). Urbanisation near dense natural forest stands may increase populations of wound-associated pests. Forest managers must recognise the potential of urban forests as a reservoir for certain pest populations, including the red turpentine beetle.
Efforts are underway to suppress the outbreak of D. valens in China by with biocontrol. Research is underway to pin-point the origin of this beetle infestation in order to find precise and effective biocontrol agents (Cognato et al. 2005). Knowledge of the origin of the introduction could provide important insight into the ecology and potential control of the D. valens (Kambhampati et al., 1991, Haymer et al., 1997, Scheffer & Grissell 2003, Cognato et al. 2005). Analysis by Cognato (2003) suggests that the likely origin of D. valens in China is the Pacific Northwest of North America.
Understanding the basic biology and ecology of the red turpentine beetle is important for developing effective management strategies. To better understand the invasion biology of the beetle basic ecological and biological questions were addressed by Liu and colleagues who found that: The red turpentine beetle male adult cannot successfully bore into a pine without a preexisting tunnel that has been bored by a female; A red turpentine beetle female can successfully bore into the tree without the presence of a male; Nearly all red turpentine beetle females who made tunnels were joined by red turpentine beetle males; A red turpentine beetle male always joined a female’s tunnel about five hours after she had built it; Both red turpentine beetle male and female adults had similar rhythms for boring into the bark, namely, both preferred to bore in the early morning (0300-0800 hours) and evening (1600-2300 hours); and Red turpentine beetle males and females had different sensitivities to volatiles: the males were sensitive to dust from holes bored by single females, and the females were more sensitive to dust from holes bored by paired male and female adults. These authors suggest that beetle pheromones mediate tree colonisation and attack behaviour.
At present in China the main method of bark beetle quarantine is to check the cargo by hand. It is hard to avoid oversight by only spot-checking the large amount of timber two to three times, when the container is full of cargo. The effect of quarantine is considerably limited by lack of advanced equipment and methods. New technology for quarantine is therefore needed (Yang 1993, in Liu & Dai 2006). It is imperative that future quarantine efforts are strengthened in order to prevent bark beetles, including the red turpentine beetle, from causing widespread damage in China (Liu & Dai 2006). In North America and Europe, much research has been done on bark beetle host orientation, interspecific olfactory communications, interspecific competition the effect of conifer oleoresin released during bark beetle attack, the effects of host volatiles on bark beetle’s reaction to pheromone and integrated management. There is no report of applying bark beetle semiochemicals for quarantine in China (Liu & Dai 2006). Using traps with two isomeric compounds of alpha-pinene, ethanol, trans-verbenol, verbenone, camphene and isononylaldehyde, Liu & Dai (2006) attracted and trapped insects of four families (Scolytidae, Platypodidae, Bostychidae and Cleridae), including eight genera of Scolytidae, (Xyleborus, Cryphalus, Polygraphs, Xyloterus, Ips, Dendroctonus, Orthotomicus and Scolytus). Research continues in China to develop new attractant formulations and practical quarantine techniques (Liu & Dai 2006).
Guandi Mountain Range
In the Guandi Mountain range (Shanxi province, China) the standard North American D. valens lure of a 1:1:1 ratio of (+)-α-pinene:(-)-β-pinene:3-carene was used in an operational mass-trapping program conducted between the months of May and June. The proportion of infested forest decreased by 64.4% and the average number of attacks per tree decreased by 59.2% (Guo et al. 2003, in Yan et al. 2005).
The Chinese State Forestry Administration currently ranks the red turpentine bark beetle as the second most important national forest pest (Yan et al. 2005). A National Management Project was initiated for D. valens in 2000. In 2001, eastern Shaanxi became infested. About 30% of the 85 300 hectares of pine forest in the province have been infested. About 7% of P. tabuliformis died in 2001. In 2002 D. valens infestations extended into Henan province but quick action by the State Forestry Administration appears to have kept damage to a minimum. Restrictions on unauthorized tree harvesting and the movement of infested material (logs, wood blocks, and wood boxes with bark) have been strictly enforced (Yan et al. 2005).
Research into the host orientation and colonisation behavior of the red turpentine beetle was conducted in Sierra Nevada (USA) The results indicated that more red turpentine beetles are attracted to wounded trees, including pines infested with black stain root disease Leptographium wageneri var. ponderosum, than to unwounded trees. Beetle infestations were identified by the presence of pitch tubes. Trees with the most D. valens pitch tubes had the greatest likelihood of being diseased and a significantly higher mortality rate. Infection by L. wageneri was confirmed for most of the trees that died, and death did not typically occur without mass attacks by the western pine beetle or the mountain pine beetle (Owen Wood & Parmeter 2005).
Red turpentine beetles usually infest pine that are aged or stressed by unfavorable growing environments, injuries or inappropriate care. To avoid bark beetle infestations one should ensure that planted pines receive proper care and a good growing environment to reduce tree stress (Seybold, Paine & Dreistadt 2008).
United States (USA)
The red turpentine beetle attacks trees wounded or stressed by construction activities (eg: paving, grading or trenching). It has been suggested that damage from the beetle can be prevented by not conducting these activities within 15 meters of large pines.
Inspection of trees for signs of the beetle are made via inspection for pitch tubes. A few pitch tubes on an otherwise healthy tree or old pitch tubes that are hardened and yellowed are generally not cause for concern. In vigorous trees the flow of resin apparently prevents egg-laying. Beetles may remain in these trees expanding their galleries laterally or vertically but they seldom deposit eggs. The appearance of five or more new pitch tubes over a couple of months warrants more careful inspection. Injury, disease, or attacks by other bark beetles are likely causes for repeated red turpentine beetle attacks. A tree that exhibits symptoms of stress and has many red turpentine beetle attacks is at high risk for mortality (Randall 2006).
Because the red turpentine beetle lives in a protected micro-habitat beneath the pine bark insecticides are not usually effective. Chemical spray applications made once the beetles have aggregated and penetrated the bark is ineffective. Treatment must target beetles during their flight activity preventing beetle attacking a new host tree. The bark of the tree is sprayed so that when the beetle lands on the pine to bore it is killed. Spraying a persistent insecticide on valuable uninfested pine at risk of infestation be warranted.
Protective spraying for bark beetles must be done by a licensed pesticide applicator. Pyrethroids (such as Astro or Dragnet) or any of the flowable (EC) formulations of carbaryl may be applied to protect healthy trees from bark beetle infestations. In most cases, the time to apply is in late winter to early spring in warm lowland areas.
Infested tree or tree limbs may be removed and chipped or burned. General hygeine principles should be followed. For example stumps of infested trees provide optimum breeding grounds for the red turpentine beetle and should be extracted and disposed of sensibly. No infested material should be piled next to, or anywhere near, a suceptible pine tree.
Only pine species adapted to a habitat should be planted. If bark beetles are a threat only non-host trees should be planted. In North America, appropriate species would include redwoods or atlas cedars. A mixture of tree species in planted landscapes will reduce mortality resulting from bark beetles and wood borers. Stresses placed on trees caused by poor planting, planting at the wrong time of year or lack of proper care afterwards will increase a trees susceptibility to bark beetles or wood borers. (Seybold, Paine & Dreistadt 2008)
2. Cognato, Anthony I., 2003. Population genetics of Dendroctonus valens LeConte introduced to China. This presentation is part of : Ten-Minute Papers, Section A. Systematics, Morphology, and Evolution, Wednesday, 29 October 2003 - 8:36 AM 0837.
Summary: Abstract: The red turpentine bark beetle, Dendroctontus valens LeConte, is a native of North America and is distributed from Central America, Mexico, western US, Canada and northeastern US. Mostly dead or dying Pinus, Picea and Abies are hosts but unhealthy live trees are sometimes killed. Recently epidemic populations of this species have been discovered in Shaxi, Shaaxi, Hebei and Henan Provinces, China. So far over half million hectares of drought stressed, Pinus tabuliformis have been infested. Biology and ecology of the red turpentine bark beetle varies within its native range thus biological control (e.g. parasitoids and pheromones) must tailored to each population. Unknown origin(s) of the Chinese beetles hampers the implementation of biological control. This study uses a portion of the mitochondrial cytochrome oxidase I gene as a molecular marker to identify potential origin(s), size and occurrence of introduction(s) to China. Thirty-four DNA haplotypes were observed among 65 D. valens individuals from eight western US populations and four haplotypes were found in China. Ten parsimony informative characters were observed among the haplotypes. Parsimony analysis resulted in 8800 trees and the strict consensus of these trees was mostly unresolved. These data and analysis do not pinpoint the exact origin of the infestation. However the results suggest that the likely origin is the Pacific Northwest of North America. Also the occurrence of multiple haplotypes in China suggests that the population did not derive from one ancestor. Either multiple families arrived with one introduction of infested wood or several introductions of infested wood occurred.
Available from: http://esa.confex.com/esa/2003/techprogram/paper_10424.htm [Accessed 14 November 2008]
3. Erbilgin, N., S. R. Mori., J. H. Sun., J. D. Stein., D. R. Owen., L. D. Merrill., R. Campos Bolaños., K. F. Raffa., T. Méndez Montiel., D. L. Wood and N. E. Gillette., 2007. Response to Host Volatiles by Native and Introduced Populations of Dendroctonus valens (Coleoptera: Curculionidae, Scolytinae) in North America and China. Journal of Chemical Ecology. Volume 33, Number 1 / January, 2007
4. Fettig, Christopher J.; Borys, Robert R.; McKelvey, Stephen R.; Dabney, Christopher P., 2008. Blacks Mountain Experimental Forest: bark beetle responses to differences in forest structure and the application of prescribed fire in interior ponderosa pine. Canadian Journal of Forest Research. 38(5). MAY 2008. 924-935.
Summary: Abstract: Mechanical thinning and the application of prescribed fire are commonly used tools in the restoration of fire-adapted forest ecosystems. However, few studies have explored their effects on subsequent amounts of bark beetle caused tree mortality in interior ponderosa pine, Pinus ponderosa Dougl. ex P. & C. Laws. var. ponderosa. In this study, we examined bark beetle responses to creation of midseral (low diversity) and late-seral stages (high diversity) and the application of prescribed fire on 12 experimental units ranging in size from 76 to 136 ha. A total of 9500 (5.0% of all trees) Pinus and Abies trees died 2 years after treatment of which 28.8% (2733 trees) was attributed to bark beetle colonization. No significant difference in the mean percentage of trees colonized by bark beetles was found between low diversity and high diversity. The application of prescribed fire resulted in significant increases in bark beetle caused tree mortality (all species) and for western pine beetle, Dendroctonus brevicomis LeConte, mountain pine beetle, Dendroctonus ponderosae Hopkins, Ips spp., and fir engraver, Scolytus ventralis LeConte, individually. Approximately 85.6% (2339 trees) of all bark beetle caused tree mortality occurred on burned split plots. The implications of these and other results to sustainable forest management are discussed.
5. Fettig, Christopher J.; Borys, Robert R; Dabney, Christopher P.; McKelvey, Stephen R.; Cluck, Daniel R.; Smith, Sheri L., 2005. Disruption of red turpentine beetle attraction to baited traps by the addition of California fivespined ips pheromone components. Canadian Entomologist. 137(6). NOV-DEC 2005. 748-752.
Summary: Abstract: The red turpentine beetle, Dendroctonits valens LeConte (Coleoptera: Scolytidae), is a common bark beetle species found throughout much of North America. In California, D. valens and the California fivespined ips, Ips paraconfusus Lanier (Coleoptera: Scolytidae), are sympatric and often colonize the same tree. In an unrelated study, we observed that I. paraconfusus attack densities in logging debris were inversely related to D. valens attacks on freshly cut stumps. In this study, we test the hypothesis that allomonal inhibition occurs between these two species. Components of the aggregation pheromone of I. paraconfusus (racemic ipsenol, (+)-ipsdienol, and (-)-cis-verbenol) inhibited the response of D. valens to attractant-baited traps. Substitution of racemic ipsdienol for (+)-ipsdienol did not alter this effect. Doubling the release rate did not enhance inhibition. Racemic ipsdienol was not attractive to I. paraconfusus. Temnochila chlorodia (Mannerheim, 1843) (Coleoptera: Trogositidae), a common bark beetle predator, was attracted to the I. paraconfusus aggregation pheromone. These results could have important implications for the development of an effective semiochemical-based management tool for D. valens.
6. Fettig, Christopher J.; Dabney, Christopher P.; McKelvey, Stephen R.; Huber, Dezene P. W., 2008. Nonhost angiosperm volatiles and verbenone protect individual ponderosa pines from attack by western pine beetle and red turpentine beetle (Coleoptera : Curculioniclae, Scolytinae). Western Journal of Applied Forestry. 23(1). JAN 2008. 40-45.
Summary: Abstract: Nonhost angiosperm volatiles (NAV) and verbenone were tested for their ability to protect individual ponderosa pines, Pinus ponderoso Dougl. ex. Laws., from attack by western pine beetle (M), Dendroctonus brevicomis LeConte, and red turpentine beetle (M), Dendroctonus valens LeConte (Coleoptera: Curculioniclae, Scolytinae). A combination of (-)-verbenone and eight NAVs [benzyl alcohol, benzaldehyde, guaiacol, nonanal, salicylaldehyde, (E)-2-hexenal, (E)-2-hexen-1-ol, and (Z)-2-hexen-1-ol] (NAVV) significantly reduced the density of WPB attacks and WPB successful attacks on attractant-baited trees. A significantly higher percentage of pitchouts (unsuccessful WPB attacks) occurred on NAVV-treated trees during two of three sample dates. In addition, significantly fewer RTB attacks were observed on NAVV-treated trees during all sampling dates. The application of NAVV to individual ponderosa pines significantly reduced tree mortality, with only 4 of 30 attractant-baited trees dying from hark beetle attack while 50% mortality (15/30) was observed in the untreated, baited control. To our knowledge, this is the first report establishing the effectiveness of NAVs and verbenone for protecting individual ponderosa pines from WPB attack.
7. Gillette, Nancy E., John D . Stein., Donald R . Owen., Jeffrey N . Webster., Gary O . Fiddler., Sylvia R . Mori and David L . Wood., 2006. Verbenone-releasing flakes protect individual Pinus contorta trees from attack by Dendroctonus ponderosae and Dendroctonus valens (Coleoptera: Curculionidae, Scolytinae) Agricultural and Forest Entomology (2006) 8, 243–251
8. Joseph, Gladwin., Rick G. Kelsey., Robert W. Peck and Chris G. Niwa., 2001. Responses of some scolytids and ther predators to Ethanol and 4-Allylanisole in Pine forests of Central Oregon. Journal of Chemical Ecology, Vol. 27, No. 4, 2001
9. Liu HaiJun, Luo YouQing, Wen JunBao, Zhang ZhiMing, Feng JiHua, Tao WanQiang., 2005. Pest risk assessment of Dendroctonus valens, Hyphantria cunea and Apriona swainsoni in Beijing area. Journal of Beijing Forestry University, 2005 (Vol. 27) (No. 2) 81-87
Summary: Abstract: According to the international methods of pest risk analysis and characteristics of urban forestry in Beijing, a quantitative risk assessment system in Beijing for the main non-indigenous pests was proposed. This system was used to analyze three non-indigenous species, Dendroctonus valens, Hyphantria cunea and Apriona swainsoni. The results show that the risk of these three species in the Beijing area is 2.46, 2.30 and 2.02, all highly risky. Based on the result and extensive risk communications combined with the management experience of the Beijing Forest Protection Station, the authors proposed that effective control measures are adopted to prevent these three pests from entering Beijing area.
11. Liu, Zhudong; Zhang, Longwa; Sun, Jianghua., 2006. Attacking behavior and behavioral responses to dust volatiles from holes bored by the red turpentine beetle, Dendroctonus valens (Coleoptera : Scolytidae). Environmental Entomology. 35(4). AUG 2006. 1030-1036.
13. Miao ZhenWang, Zhang ZhongNing, Wang PeiXin, Guo YuYong, Sun JiangHua., 2004. Response of the red turpentine beetle, Dendroctonus valens LeConte (Coleoptera: Scolytidae) to host semiochemicals and its implication in management. Acta Entomologica Sinica, 2004 (Vol. 47) (No. 3) 360-364
Summary: Abstract: The red turpentine beetle (RTB), D. valens, an invasive pest from the United States became a major forest pest in its invading areas since its first outbreak in Shanxi Province, China in 1999. As an exotic pest, effective detection and monitoring is top priority in containing its further damage. The response of RTB to its host semiochemicals was explored in Shanxi Province using Lindgren funnel trap. The results indicated that 3-carene was found to be the most attractive host monoterpene tested, and it attracted significantly more beetles than did any other single or ternary blend, which was distinctly different from the previous reports conducted in its native range, west coast of the United States. The mechanism for this regional variation of RTB response to host volatiles was discussed. Increase of (-)-ß-pinene did not result in any increase of beetles trapped while adding limonene which is another main component in volatile profile of Pinus tabulaeformis, to the standard lure used in North America (a 1:1:1 blend of (+)-a-pinene, (-)-ß-pinene, and 3-carene) significantly decreased RTB response. The effect of release rate on RTB response was tested by using the standard blend at 110 mg/day, 150 mg/day, 180 mg/day and 210 mg/day, and 150 mg/day was found to be the most optimum release rate for RTB in terms of both attractiveness and economic efficiency. Thus, this effective RTB lure can be used in RTB monitoring and control.
14. Raffa, K. F & Smalley E. B., 1988. Host resistance to invasion by lower stem and root infesting insects of pine: response to controlled inoculations with the fungal associate Leptographium terebrantis. Canadian journal of forest research. 1988, vol. 18, no6, pp. 675-681 (3 p.)
16. Rappaport, Nancy Gillette, Donald R. Owen and John D. Stein. 2001. Interruption of Semiochemical-Mediated Attraction of Dendroctonus valens (Coleoptera: Scolytidae) and Selected Nontarget Insects by Verbenone. Environmental Entomology Article: pp. 837–841
17. Schweigkofler, Wolfgang; Otrosina, William J.; Smith, Sheri L.; Cluck, Daniel R.; Maeda, Kevin; Peay, Kabir G.; Garbelotto, Matteo., 2005. Detection and quantification of Leptographium wageneri, the cause of black-stain root disease, from bark beetles (Coleoptera : Scolytidae) in Northern California using regular and real-time PCR. Canadian Journal of Forest Research. 35(8). AUG 2005. 1798-1808.
20. Sun, Jianghua., Zhengwan Miao., Zhen Zhang., Zhongning Zhang and Nancy Gillette., 2004. Red Turpentine Beetle, Dendroctonus valens LeConte (Coleoptera: Scolytidae), Response to Host Semiochemicals in China. Environmental Entomology Volume 33, Issue 2 (April 2004) pp. 206–212
22. Wallin, Kimberly F.; Kolb, Thomas E.; Skov, Kjerstin R.; Wagner, Michael., 2008. Forest management treatments, tree resistance, and bark beetle resource utilization in ponderosa pine forests of northern Arizona. Forest Ecology & Management. 255(8-9). MAY 15 2008. 3263-3269
23. Zhang, Longwa., Jianghua Sun., and Stephen R. Clarke., 2006. Effects of Verbenone Dose and Enantiomer on the Interruption of Response of the Red Turpentine Beetle, Dendroctonus valens LeConte (Coleoptera: Scolytidae), to Its Kariomones. Environmental Entomology Volume 35, Issue 3 (June 2006)
24. Zhang, Long-wa; Gillette, Nancy E.; Sun, Jiang-hua., 2007. Electrophysiological and behavioral responses of Dendroctonus valens to non-host volatiles. Annals of Forest Science. 64(3). APR-MAY 2007. 267-273.
Summary: Abstract: Non-host volatiles (NHVs) that are often reported as being disruptive to coniferophagous bark beetles were tested for both electrophysiological and behavioral effects on the red turpentine beetle, Dendroctonus valens LeConte (Coleoptera: Curculionidae: Scolytinae), which was accidentally introduced into China in the mid-1980' s. All NHVs tested elicited dose-dependent antennal responses by D. valens. In Y-tube olfactometer trials, D. valens were repelled by NHVs tested. When NHVs were added to a kairomone blend, responses of D. valens were significantly inhibited. Further field trapping experiments showed that attraction of D. valens to kairomone baited traps was reduced by all individual NHVs, with reductions ranging from 26.3 to 70%. 1-Octen-3-ol, (Z)-3-hexen-1-ol, and (E)-2-hexen-1-ol were the three most effective NHVs, significantly reducing D. valens to kairomone-baited traps by 69.5, 68.3 and 66.0%, respectively. In the development and implementation of a semiochemical-based management programme for D. valens, NHVs may have considerable potential for disrupting the beetle's ability to locate suitable hosts.
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