Semiochemicals produced by western balsam bark beetle,Dryocoetes confusus Swaine (Coleoptera: Scolytidae)

1987 ◽  
Vol 13 (4) ◽  
pp. 823-836 ◽  
Author(s):  
J. H. Borden ◽  
A. M. Pierce ◽  
H. D. Pierce ◽  
L. J. Chong ◽  
A. J. Stock ◽  
...  
Keyword(s):  
Bark Beetle ◽  
Dryocoetes Confusus

Response of Dryocoetes confusus and D. autographus (Coleoptera: Scolytidae) to enantiospecific pheromone baits

2004 ◽  
Vol 136 (3) ◽  
pp. 419-425 ◽  
Author(s):  
N.L. Jeans Williams ◽  
J.H. Borden
Keyword(s):  
Bark Beetle ◽  
Aggregation Pheromone ◽  
Bark Beetles ◽  
Field Studies ◽  
Pheromone Component ◽  
Male And Female ◽  
Dryocoetes Confusus

AbstractIn past field studies, the greatest response of western balsam bark beetles, Dryocoetes confusus Swaine, to traps was obtained with blends of (+)-exo-brevicomin and (+)- or (±)-endo-brevicomin, which imitate the natural male-produced aggregation pheromone. We conducted a trapping experiment comparing low-release enanti ospecific blends (9:1 (+)-exo-brevicomin:(+)-endo-brevicomin or 9:2 (+)-exo-brevicomin:(±)-endo-brevicomin released at 0.3, 0.1, or 0.03 mg per day) with the standard commercial (±)-exo-brevicomin bait released at 1.2 mg per day. Multiple-funnel traps baited with the experimental blends caught more D. confusus than the unbaited traps, but only traps with the 9:2 (+):(±) blend released at 0.3 and 0.03 mg per day caught significantly more male and female beetles than those baited with the standard bait. Thus, trap sensitivity can be improved with the addition of (±)-endo-brevicomin. The sympatric bark beetle D. autographus Ratzeburg was captured in significant numbers in traps baited with (±)-exo-brevicomin. A subsequent trapping experiment showed that D. autographus responded to (+)- or (±)-exo-brevicomin, but not to (−)-exo-brevicomin, suggesting that (+)-exo-brevicomin is the principal aggregation pheromone component in this species.

Late Glacial and Holocene records of tree-killing conifer bark beetles in Europe and North America: Implications for forest disturbance dynamics

The Holocene ◽  
2020 ◽  
Vol 30 (6) ◽  
pp. 847-857 ◽  
Author(s):  
Nick Schafstall ◽  
Niina Kuosmanen ◽  
Christopher J Fettig ◽  
Miloš Knižek ◽  
Jennifer L Clear
Keyword(s):  
North America ◽  
Bark Beetle ◽  
Fossil Record ◽  
Bark Beetles ◽  
Late Glacial ◽  
Ips Paraconfusus ◽  
Distribution Data ◽  
Dryocoetes Confusus ◽  
Combining Data ◽  
Fossil Records

Outbreaks of conifer bark beetles in Europe and North America have increased in scale and severity in recent decades. In this study, we identify existing fossil records containing bark beetle remains from the end of the Last Glacial Maximum (~14,000 cal. yr BP) to present day using the online databases Neotoma and BugsCEP and literature searches, and compare these data with modern distribution data of selected tree-killing species. Modern-day observational data from the Global Biodiversity Information Facility (GBIF) database was used to map recorded distributions from AD 1750 to present day. A total of 53 fossil sites containing bark beetle remains, from both geological and archeological sites, were found during our searches. Fossil sites were fewer in Europe ( n = 21) than North America ( n = 32). In Europe, 29% of the samples in which remains were found were younger than 1000 cal. yr BP, while in North America, remains were mainly identified from late Glacial (~14,000–11,500 cal. yr BP) sites. In total, the fossil records contained only 8 of 20 species we consider important tree-killing bark beetles in Europe and North America based on their impacts during the last 100 years. In Europe, Ips sexdentatus was absent from the fossil record. In North America, Dendroctonus adjunctus, Dendroctonus frontalis, Dendroctonus jeffreyi, Dendroctonus pseudotsugae, Dryocoetes confusus, Ips calligraphus, Ips confusus, Ips grandicollis, Ips lecontei, Ips paraconfusus, and Scolytus ventralis were absent. Overall, preserved remains of tree-killing bark beetles are rare in the fossil record. However, by retrieving bulk material from new and existing sites and combining data from identified bark beetle remains with pollen, charcoal, tree rings, and geochemistry, the occurrence and dominance of bark beetles, their outbreaks, and other disturbance events can be reconstructed.

DIFFERENTIAL BIOACTIVITY OF CONOPHTHORIN ON FOUR SPECIES OF NORTH AMERICAN BARK BEETLES (COLEOPTERA: SCOLYTIDAE)

2000 ◽  
Vol 132 (5) ◽  
pp. 649-653 ◽  
Author(s):  
Dezene P.W. Huber ◽  
John H. Borden ◽  
Nicole L. Jeans-Williams ◽  
Regine Gries
Keyword(s):  
Bark Beetle ◽  
Bark Beetles ◽  
Dependent Manner ◽  
Dendroctonus Pseudotsugae ◽  
Dendroctonus Rufipennis ◽  
Pine Engraver ◽  
Dryocoetes Confusus ◽  
Baited Traps ◽  
Spruce Beetle ◽  
Dose Dependent

AbstractThe angiosperm bark volatile, conophthorin, was tested at release rates of 3.0 and 0.3 mg/24 h against the Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins, the spruce beetle, Dendroctonus rufipennis (Kirby), the pine engraver, Ips pint (Say), and the western balsam bark beetle, Dryocoetes confusus Swaine (all Coleoptera: Scolytidae). The responses of D. pseudotsugae, I. pini, and (in one of two experiments) female D. confusus to attractant-baited traps were disrupted by conophthorin in a dose-dependent manner. Dendroctonus rufipennis was not disrupted by conophthorin. Our results extend the repellent bioactivity of conophthorin to Ips DeGeer spp. and confirm earlier experiments with D. pseudotsugae. Conophthorin may have some utility in protecting susceptible timber from bark beetle attack.

PATHOGENIC FUNGI ASSOCIATED WITH A BARK BEETLE ON ALPINE FIR

1965 ◽  
Vol 43 (5) ◽  
pp. 563-570 ◽  
Author(s):  
A. C. Molnar
Keyword(s):  
Bark Beetle ◽  
Pathogenic Fungi ◽  
The Other ◽  
Blue Staining ◽  
Abies Lasiocarpa ◽  
Decay Fungi ◽  
Inner Bark ◽  
Dryocoetes Confusus

Unexplained mortality associated with attacks of the western balsam bark beetle (Dryocoetes confusus Sw.) in alpine fir (Abies lasiocarpa (Hook.) Nutt.) was found to be caused by a beetle–fungus complex. Not all trees attacked were killed, but surviving trees were left with lesions which provided potential entrance courts for decay fungi. Four closely related fungi, isolated from necrotic lesions centered at beetle bore holes, were shown by inoculation to be pathogenic. Ceratocystis dryocoetidis Kendrick and Molnar was the most virulent of these fungi on the basis of the size of lesions produced. C. dryocoetidis caused cambial and inner bark necrosis, while the other three fungi produced necrosis and blue staining of the sapwood.

RESPONSE OF THE WESTERN BALSAM BARK BEETLE, DRYOCOETES CONFUSUS SWAINE (COLEOPTERA: SCOLYTIDAE), TO HOST TREES BAITED WITH ENANTIOSPECIFIC BLENDS OF EXO- AND ENDO-BREVICOMIN

1994 ◽  
Vol 126 (1) ◽  
pp. 43-48 ◽  
Author(s):  
Alejandro D. Camacho ◽  
John H. Borden
Keyword(s):  
British Columbia ◽  
Bark Beetle ◽  
Abies Lasiocarpa ◽  
Dryocoetes Confusus ◽  
Host Trees

AbstractThe response of the western balsam bark beetle, Dryocoetes confusus Swaine, to subalpine firs, Abies lasiocarpa (Hook.) Nutt., baited with (±)-exo-brevicomin (EXOB) or 9:1 blends of EXOB and endo-brevicomin (ENDOB), in two chiral combinations: (+):(±) and (+):(+), was assessed in a heavily infested stand in British Columbia. Unbaited control trees were not attacked, and the proportion of mass-attacked baited trees was similar for all other treatments. However, trees baited with the (+):(+) blend had the highest number of attacks per square metre, and they were also surrounded by the most attacked trees. The (+):(±) blend was intermediate in attractancy, and (±)EXOB was the least attractive bait. Pheromone-based management of D. confusus infestations may be more effective with the 9:1 blend of (+)EXOB:(+)ENDOB than with the previously used (±)EXOB baits.

scholarly journals Effects of Western Balsam Bark Beetle on Spruce-Fir Forests of North-Central Wyoming

2003 ◽  
Vol 18 (4) ◽  
pp. 259-266 ◽  
Author(s):  
Joel D. McMillin ◽  
Kurt K. Allen ◽  
Daniel F. Long ◽  
Jeri Lyn Harris ◽  
José F. Negrón
Keyword(s):  
Bark Beetle ◽  
Basal Area ◽  
Stand Density ◽  
Herbaceous Plant ◽  
North Central ◽  
Subalpine Fir ◽  
Dryocoetes Confusus ◽  
Density Index ◽  
Stand Density Index ◽  
Stand Conditions

Abstract Western balsam bark beetle, Dryocoetes confusus (Coleoptera: Scolytidae), has caused widespread mortality of subalpine fir (Abies lasiocarpa) in western North America throughout the past decade. The objectives of this study were to document the effects of this mortality, relate mortality to pre-existing stand conditions, and investigate the role of storm-damaged fir in beetle population dynamics in north-central Wyoming. Transect cruise lines and pairs of infested and uninfested plots were installed to detect changes in the forest overstory and understory and to determine associations between stand conditions and beetle-caused fir mortality. On average, beetles killed more than 70 trees/ac over the last several years. This mortality resulted in significant decreases in: subalpine fir basal area, trees per acre, stand density index, and the percentage of subalpine fir stems in the overstory. Small, but significant increases were detected in the understory; herbaceous plant abundance increased in the infested plots compared with the noninfested plots. Moreover, significant positive linear relationships were found between the amount of fir mortality and the percentage of subalpine fir trees in a stand, subalpine fir basal area, and subalpine fir stand density index. In addition, a significant positive linear relationship was found between the percentage of wind-caused downed fir logs in an area and the percentage of logs utilized by western balsam bark beetle. The blowdown events that occurred in the mid-1990s in combination with a high percentage of fir component has provided ideal conditions for continued beetle expansion. West. J. Appl. For. 18(4):259–266.

OCCURRENCE OF MYCANGIA IN THE BARK BEETLE DRYOCOETES CONFUSUS (COLEOPTERA: SCOLYTIDAE)

1969 ◽  
Vol 101 (5) ◽  
pp. 527-532 ◽  
Author(s):  
S. H. Farris
Keyword(s):  
Bark Beetle ◽  
Dryocoetes Confusus ◽  
Dryocoetes Affaber

AbstractPaired mandibular mycangia are present in both sexes of the bark beetle Dryocoetes confusus Sw. These fungus repositories were not found in either sex of another bark beetle of the same genus, Dryocoetes affaber Mann.

ENANTIOMERIC COMPOSITION AND RELEASE RATES OF exo-BREVICOMIN INFLUENCE AGGREGATION OF THE WESTERN BALSAM BARK BEETLE, DRYOCOETES CONFUSUS SWAINE (COLEOPTERA: SCOLYTIDAE)

1995 ◽  
Vol 127 (4) ◽  
pp. 449-456 ◽  
Author(s):  
Arthur J. Stock ◽  
J.H. Borden ◽  
T.L. Pratt ◽  
H.D. Pierce ◽  
B.D. Johnston
Keyword(s):  
Bark Beetle ◽  
Field Experiments ◽  
Enantiomeric Composition ◽  
Release Rates ◽  
Dryocoetes Confusus ◽  
Better Than

AbstractField experiments demonstrated that the western balsam bark beetle, Dryocoetes confusus, responded best to multiple-funnel traps baited with mixtures of (+)- and (−)-exo-brevicomin. (±)-exo-Brevicomin released at 0.8 mg per 24 h performed as well as or better than release rates of from 0.2 to 1.0 mg per 24 h in terms of the number of baited trees which were mass attacked (80%), average attack density, and average number of trees attacked within a 10-m radius of baited trees. Baiting more than one tree in a spot resulted in an intensification of attack on baited trees and increased the number of trees attacked within 10 m of each spot.

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