The role of host tree condition in attack of white oaks by the twolined chestnut borer, Agrilus bilineatus (Weber) (Coleoptera: Buprestidae)

Oecologia ◽  
1986 ◽  
Vol 70 (4) ◽  
pp. 596-600 ◽  
Author(s):  
James P. Dunn ◽  
Thomas W. Kimmerer ◽  
Gerald L. Nordin
Keyword(s):  
Host Tree ◽  
Tree Condition

scholarly journals Bark beetles locate fungal symbionts by detecting volatile fungal metabolites of host tree resin monoterpenes

2021 ◽  
Author(s):  
Dinesh Kandasamy ◽  
Rashaduz Zaman ◽  
Yoko Nakamura ◽  
Tao Zhao ◽  
Henrik Hartmann ◽  
...  
Keyword(s):  
Bark Beetles ◽  
De Novo ◽  
Host Tree ◽  
Bornyl Acetate ◽  
Conifer Forest ◽  
Mature Trees ◽  
Breeding Sites ◽  
Spruce Bark ◽  
Short Period

Outbreaks of bark beetles have decimated millions of hectares of conifer forest worldwide in recent years. The ability of these tiny 3-6 mm long insects to kill mature trees over a short period has been ascribed to two factors: (1) mass attacks on the host tree to overcome tree defenses and (2) the presence of fungal symbionts that support successful beetle development in the tree. While the role of pheromones in coordinating mass attacks has been well studied, the role of chemical communication in maintaining the fungal symbiosis is poorly understood. We previously demonstrated that Eurasian spruce bark beetles (Ips typographus) can recognize beneficial fungal symbionts of the genera Grosmannia, Endoconidiophora and Ophiostoma by their de novo synthesized volatile compounds. We hypothesized that the fungal symbionts of the bark beetles might metabolize spruce resin monoterpenes of the beetle host tree, Norway spruce (Picea abies), and that the volatile products could be used as cues by beetles for locating breeding sites with beneficial symbionts. Grosmannia penicillata and other fungal symbionts altered the profile of spruce bark volatiles by converting the major monoterpenes to oxygenated derivatives. Bornyl acetate was metabolized to camphor, and α- and β-pinene to trans-4-thujanol and other oxygenated products. Extensive electrophysiological measurements showed that bark beetles possess olfactory sensory neurons that are selective for these oxygenated symbiont metabolites. Compounds such as camphor and trans-4-thujanol attracted beetles at specific doses in olfactory experiments and stimulated the response of female beetles to a mixture of pheromones. Finally, the fungal symbiont was found to stimulate bark beetle tunneling on diets. Collectively, our results show that oxygenated metabolites of conifer monoterpenes produced by fungal symbionts are used by bark beetles as cues to find these essential microbial symbionts. The oxygenated metabolites may aid beetles in assessing the presence of the fungus, the defense status of the host tree and the density of conspecifics at potential feeding and breeding sites.

Influence of Host Tree Condition on the Performance ofTetropium fuscum(Coleoptera: Cerambycidae)

2011 ◽  
Vol 40 (5) ◽  
pp. 1200-1209 ◽  
Author(s):  
Leah Flaherty ◽  
Jon D. Sweeney ◽  
Deepa Pureswaran ◽  
Dan T. Quiring
Keyword(s):  
Host Tree ◽  
Tree Condition

Diapause and its regulation in the whitefly Trialeurodes lauri

2010 ◽  
Vol 101 (6) ◽  
pp. 741-747 ◽  
Author(s):  
D. Gerling ◽  
M. Guershon ◽  
E. Erel ◽  
M. Inbar
Keyword(s):  
Life Cycle ◽  
Host Plant ◽  
Fourth Instar ◽  
Host Tree ◽  
First Report ◽  
Laboratory Conditions

AbstractThis study focuses on the regulation of synchronization between the life cycle of the oligophagous whitefly, Trialeurodes lauri (Signoret), and its evergreen host tree Arbutus andrachne in Mediterranean chaparral. Whitefly infestations vary considerably among trees. The adults of the univoltine (one generation per year) whitefly emerge en masse during April and May and oviposit on the new spring foliage. Following approximately one month of development to the early fourth instar, the nymphs enter nine-month diapauses, terminating in February. This diapause is induced and maintained by the plant and can be experimentally avoided (in the case of developing young nymphs) or terminated (in the case of diapausing fourth instars), if whitefly-bearing branches are severed from the tree and placed in water under laboratory conditions. This study is the first report of a whitefly diapausing through both summer and winter seasons. The role of the host plant in the process is discussed.

Diagnostic Accuracy of ACR/EULAR 2010 Criteria for Rheumatoid Arthritis in a 2-Year Cohort

2011 ◽  
Vol 38 (7) ◽  
pp. 1250-1257 ◽  
Author(s):  
SOPHIE VARACHE ◽  
DIVI CORNEC ◽  
JOHANNE MORVAN ◽  
VALÉRIE DEVAUCHELLE-PENSEC ◽  
JEAN-MARIE BERTHELOT ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Diagnostic Accuracy ◽  
Predictive Value ◽  
Exclusion Criteria ◽  
Recent Onset ◽  
American College Of Rheumatology ◽  
European League Against Rheumatism ◽  
Sensitivity Specificity ◽  
Tree Condition

Objective.To evaluate the diagnostic accuracy of the 2010 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) and 1987 ACR criteria for rheumatoid arthritis (RA), and the respective role of the algorithm and scoring of the ACR/EULAR.Methods.In total, 270 patients with recent-onset arthritis of < 1 year duration were included prospectively between 1995 and 1997 and followed for 2 years. RA was defined as the combination, at completion of followup, of RA diagnosed by an office-based rheumatologist and treatment with a disease-modifying antirheumatic drug or glucocorticoid. We compared the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the criteria sets in the overall population, in the subgroup meeting the tree condition for ACR/EULAR scoring, and in the overall population classified according the full tree.Results.At baseline, 111 of the 270 patients had better alternative diagnoses and 16 had erosions typical for RA; of the 143 remaining patients, 52 had more than 6 ACR/EULAR 2010 points (indicating definite RA) and 91 had fewer than 6 points. After 2 years, 11/16 patients with erosions and 40/52 with more than 6 points had RA. 100 of the 270 patients met the reference standard for RA. Sensitivity, specificity, PPV, and NPV of the ACR/EULAR (full tree) were 51/100 (51%), 153/170 (90%), 51/68 (75.4%), and 153/202 (75.7%), respectively. Diagnostic accuracies of the ACR/EULAR score and ACR 1987 criteria were not statistically different.Conclusion.Much of the improvement of the ACR/EULAR criteria was ascribable to the use of exclusion criteria in the algorithm.

Attraction of Adult Plum Curculios (Coleoptera: Curculionidae) to Host-Tree Odor and Visual Stimuli in the Field

1997 ◽  
Vol 32 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Susan L. Butkewich ◽  
Ronald J. Prokopy
Keyword(s):  
Visual Cues ◽  
Field Tests ◽  
Host Tree ◽  
Conotrachelus Nenuphar ◽  
Small Tree ◽  
Plum Curculio ◽  
Host Trees ◽  
Maple Leaves ◽  
Host Odor

Field tests were conducted to determine if plum curculios, Conotrachelus nenuphar (Herbst), responded to host odor and/or visual cues to locate host trees. Experiment 1 investigated the role of odor in host location. Host branchlets (apple leaves and fruit) were compared with non-host branchlets (maple leaves). Significantly more released color-marked plum curculios arrived on screen cages containing apple branchlets than on screen cages containing maple branchlets. Experiment 2 investigated the role of visual cues, with or without host odor, in host tree location. Plum curculios arrived preferentially on 60 cm wide × 130 cm tall sticky green rectangles (intended to mimic the canopy of a small tree) with associated caged apple branchlets than on sticky clear Plexiglas rectangles with caged apple branchlets or on sticky green or clear Plexiglas rectangles with caged maple branchlets. These data suggest that plum curculio adults may use both odor and visual cues to locate host trees during spring migration from overwintering sites.

scholarly journals Which trees die during drought? The key role of insect host‐tree selection

2019 ◽  
Vol 107 (5) ◽  
pp. 2383-2401 ◽  
Author(s):  
Nathan L. Stephenson ◽  
Adrian J. Das ◽  
Nicholas J. Ampersee ◽  
Beverly M. Bulaon ◽  
Julie L. Yee
Keyword(s):  
Host Tree ◽  
Insect Host

Diversity of xylariaceous symbionts in Xiphydria woodwasps: role of vector and a host tree

2010 ◽  
Vol 3 (4) ◽  
pp. 392-401 ◽  
Author(s):  
Sylvie Pažoutová ◽  
Petr Šrůtka ◽  
Jaroslav Holuša ◽  
Milada Chudíčková ◽  
Miroslav Kolařík
Keyword(s):  
Host Tree
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