scholarly journals Shallow Genetic Structure among the European Populations of the Six-Toothed Bark Beetle Ips sexdentatus (Coleoptera, Curculionidae, Scolytinae)

Forests ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 136 ◽  
Author(s):  
Dimitrios N. Avtzis ◽  
Ferenc Lakatos ◽  
Diego Gallego ◽  
Milan Pernek ◽  
Massimo Faccoli ◽  
...  
Keyword(s):  
Bark Beetle ◽  
Host Preference ◽  
Glacial Refugia ◽  
Intraspecific Diversity ◽  
Biological Traits ◽  
Population Outbreaks ◽  
Ips Sexdentatus ◽  
Southern European Countries ◽  
Shallow Structure ◽  
Mtdna Marker

The six-toothed bark beetle, Ips sexdentatus, is one of the most abundant scolytid species of the central and southern European countries. It mostly feeds on Pinus sp., whereas during population outbreaks it can also attack Picea sp. In spite of its broad distribution, its phylogeography has never been studied before. To do that, we employed an mtDNA marker on 489 individuals that covered most of its native range in Europe. Geographic distribution of the 86 haplotypes showed that at least three glacial refugia have played a significant role in shaping the currently observed pattern of genetic divergence in Europe, without excluding the contribution of minor refugial areas that acted in a similar manner. The revealed shallow structure can be considered an artifact of factors that reduced intraspecific diversity, at the same time favoring gene flow. As such, biological traits of the species itself (flying ability and host preference) and even human-mediated transport of wood seem to be the most prevailing and probable reasons that gave rise to the observed pattern.

scholarly journals Effects of forest roads on Ips sexdentatus infestation in black pine forest

2018 ◽  
Vol 6 (7) ◽  
pp. 828
Author(s):  
Gonca Ece Özcan ◽  
Korhan Enez ◽  
Burak Arıcak
Keyword(s):  
Bark Beetle ◽  
Bark Beetles ◽  
Forest Ecosystems ◽  
Significant Risk ◽  
Pine Forests ◽  
Slope Aspect ◽  
Black Pine ◽  
Forest Roads ◽  
Forest Road ◽  
Ips Sexdentatus

Forest roads are important transportation equipment through forested areas in the rugged, mountainous terrain of northern Turkey. Forest roads harm forest ecosystems due to both the manner in which they are established and how they are used afterwards. Damage to trees that occur during road construction through forests stresses trees, which facilitates outbreaks of bark beetle populations. Bark beetles are significant risk to the health and productivity of Turkish pine forests and to pine forests worldwide. In particular, Ips sexdentatus (Boerner) (Coleoptera, Curculionidae, Scolytinae) is a particularly destructive species of bark beetle in Turkish forests. Their damage to coniferous trees threatens the sustainability of the forest ecosystems. This study primarily aims to assess the intensity of damage that I. sexdentatus inflicts on Pinus nigra J.F.Arnold stands relative to several parameters: the distance to the nearest forest road, aspect (shady - sunny), slope (0–15% or >15%), and other stand characteristics. In this study, we show how damage by an I. sexdentatus infestation in pure black pine stands varies with distance to forest roads and in situ edaphic factors. We sampled 45 plots (400 m2 each), slope, aspect and distances to the nearest forest road was determined using ArcGIS software and the region’s road network overlays. Results showed that trees located within 100 m from the nearest forest road were the most severely damaged ones. The intensity of I. sexdentatus damage was about 16% in a hectare. Trees that were in 16–20 cm diameter class were damaged more often. I. sexdentatus damage did not show any significant correlation with the slope, aspect or degree of canopy closure.

scholarly journals Phylogeographical structure of the pygmy shrew: revisiting the roles of southern and northern refugia in Europe

2020 ◽  
Vol 129 (4) ◽  
pp. 901-917 ◽  
Author(s):  
Rodrigo Vega ◽  
Allan D McDevitt ◽  
Joanna Stojak ◽  
Alina Mishta ◽  
Jan M Wójcik ◽  
...  
Keyword(s):  
Demographic History ◽  
Glacial Refugia ◽  
Intraspecific Diversity ◽  
Evolutionary Potential ◽  
Mountain Ranges ◽  
Early Diversification ◽  
Patterns And Processes ◽  
Sorex Minutus ◽  
Pygmy Shrew ◽  
The Last Glacial

Abstract Southern and northern glacial refugia are considered paradigms that explain the complex phylogeographical patterns and processes of European biota. Here, we provide a revisited statistical phylogeographical analysis of the pygmy shrew Sorex minutus Linnaeus, 1766 (Eulipotyphla, Soricidae), examining its genetic diversity, genetic differentiation and demographic history in the Mediterranean peninsulas and in Western and Central Europe. The results showed support for genetically distinct and diverse phylogeographical groups consistent with southern and northern glacial refugia, as expected from previous studies. We also identified geographical barriers concordant with glaciated mountain ranges during the Last Glacial Maximum (LGM), early diversification events dated between the Late Pleistocene and Early Holocene for the main phylogeographical groups, and recent (post-LGM) patterns of demographic expansions. This study is the most comprehensive investigation of this species to date, and the results have implications for the conservation of intraspecific diversity and the preservation of the evolutionary potential of S. minutus.

Multiscale spatial variation of the bark beetle Ips sexdentatus damage in a pine plantation forest (Landes de Gascogne, Southwestern France)

2009 ◽  
Vol 257 (7) ◽  
pp. 1551-1557 ◽  
Author(s):  
J.-P. Rossi ◽  
J.-C. Samalens ◽  
D. Guyon ◽  
I. van Halder ◽  
H. Jactel ◽  
...  
Keyword(s):  
Spatial Variation ◽  
Bark Beetle ◽  
Pine Plantation ◽  
Plantation Forest ◽  
Ips Sexdentatus

scholarly journals Phylogeographic structure of the pygmy shrew: revisiting the roles of southern and northern refugia in Europe

2019 ◽  
Author(s):  
Rodrigo Vega ◽  
Allan D. McDevitt ◽  
Joanna Stojak ◽  
Alina Mishta ◽  
Jan M. Wójcik ◽  
...  
Keyword(s):  
Demographic History ◽  
Population Expansion ◽  
Glacial Refugia ◽  
Intraspecific Diversity ◽  
Phylogeographic Structure ◽  
Evolutionary Potential ◽  
Early Diversification ◽  
Patterns And Processes ◽  
Sorex Minutus ◽  
Pygmy Shrew

ABSTRACTSouthern and northern glacial refugia are considered paradigms that explain the complex phylogeographic patterns and processes of European biota. Although the Eurasian pygmy shrew Sorex minutus Linnaeus, 1766 (Eulipotyphla, Soricidae) has been used a model species to study geographic isolation and genetic diversification in Mediterranean peninsulas in the Last Glacial Maximum (LGM), and post-glacial population expansion from cryptic northern glacial refugia in Western and Central Europe, there has been incomplete knowledge about the phylogeographic structure, genetic differentiation and demographic history within these regions. Here, we provide a revisited statistical phylogeographic study of S. minutus with greater sampling coverage in terms of numbers of individuals and geographic range, making it the most comprehensive investigation of this species to date. The results showed support for genetically distinct and diverse phylogeographic groups consistent with southern and northern glacial refugia, as expected from previous studies, but also identified geographical barriers concordant with glaciated mountain ranges during the LGM, early diversification events dated between the Upper Pleistocene and Lower Holocene for the main phylogeographic groups, and recent (post-LGM) patterns of demographic expansions. The results have implications for the conservation of intraspecific diversity and the preservation of the evolutionary potential of S. minutus.

scholarly journals Natural and insecticide-free methods for protecting wood piles from bark beetles - using the example of the ash bark beetle (Hylesinus fraxini [Panzer, 1779]) on Common Ash (Fraxinus excelsior [L.])

2020 ◽  
Vol 5 (1) ◽  
pp. 1-13
Author(s):  
Robert Friedrich ◽  
Wehnert-Kohlenbrenner Michael ◽  
Marco Schneider
Keyword(s):  
Bark Beetle ◽  
Tree Species ◽  
Bark Beetles ◽  
Fraxinus Excelsior ◽  
Effective Protection ◽  
Application Method ◽  
Ips Sexdentatus ◽  
Test Treatments ◽  
Pheromone Dispensers

This paper is investigating the insecticide-free protection of ash wood piles through the use of semiochemical dispensers with allochthonous kairomones to control ash bark beetle populations. For this purpose, borehole counts and brood gallery analyses were carried out on log piles of ash wood stored in the forest. Studies have shown that Hylesinus fraxini is repelled by the attractant dispenser with the substance mixture Sexowit, which was actually developed to catch Ips sexdentatus. In addition, the substance mixture has an aggregating effect on various bark beetle antagonists. This causality should be used to find a form of application to protect freshly stacked ash wood from H. fraxini infestation. A recommended form of application should be transferable to other bark beetle- and tree species and substances. In adaptation to the so-called Island Method of bark beetle traps, the wood piles of the five test variants were also arranged like islands. Commercially available Sexowit pheromone dispensers were used, which were attached to the piles. Besides a control without Sexowit dispenser there were test treatments with one, two, four and nine Sexowit dispensers.Within the scope of the investigation, effects between the tested variants could be determined and a recommended application method derived. Compared to control most effective protection of ash log piles was reached with variants treated with four or nine lures of Sexowit. In relation to control infestation was reduced by 78.1% on 4-dispenser variant Sexowit and 88.9% on 9-dispenser variant Sexowit.

STRUCTURES IMPLICATED IN THE TRANSPORTATION OF PATHOGENIC FUNGI BY THE EUROPEAN BARK BEETLE, IPS SEXDENTATUS BOERNER: ULTRASTRUCTURE OF A MYCANGIUM

1991 ◽  
Vol 123 (2) ◽  
pp. 245-254 ◽  
Author(s):  
J. Lévieux ◽  
P. Cassier ◽  
D. Guillaumin ◽  
A. Roques
Keyword(s):  
Bark Beetle ◽  
Pathogenic Fungi ◽  
Proximal Part ◽  
Simple System ◽  
Type Iii ◽  
Gland Cells ◽  
Ips Sexdentatus ◽  
General Organization

AbstractThe European bark beetle, Ips sexdentatus Boerner, carries fungi in puncture pits located on the proximal part of each mandible, the sides of the pronotum, and the elytra.On the pronotum, each mycangium corresponds to the cup-shaped depression surrounding each seta. Several type III gland cells are associated with each mycangium. The general organization of these cells, commonly found in the epidermis, corresponds to those described by other authors. Their finely granular secretions probably protect the fungi, assure spore adhesion, and also may temporarily inhibit their germination. Similar gland cells were scattered under unspecialized pronotal integument where fungi were not detected.Thus, it appears that this beetle has evolved a mechanism for the protection or dissemination, or both, of yeasts and fungi such as Ceratocystis sp. This relatively simple system seems to be as efficient as the more evolved mycangia of other species.

Effects of drought stress and severe pruning on the reaction zone induced by single inoculations with a bark beetle associated fungus (Ophiostoma ips) in the phloem of young Scots pines

1998 ◽  
Vol 28 (12) ◽  
pp. 1814-1824 ◽  
Author(s):  
Luc Croisé ◽  
Erwin Dreyer ◽  
François Lieutier
Keyword(s):  
Water Stress ◽  
Reaction Zone ◽  
Bark Beetle ◽  
Severe Water Stress ◽  
Reaction Zones ◽  
Maximum Water ◽  
Ips Sexdentatus ◽  
Effects Of Drought ◽  
Two Parameters ◽  
Needle Water Potential

The objective of this study was to test the effect of water stress and pruning on the resistance of young Scots pines (Pinus sylvestris L.) to a bark beetle associated fungus. Six-year-old potted trees were either pruned (70% of needles removed) or subjected to several successive episodes of severe water stress, prior to inoculation of inner bark with the fungus Ophiostoma ips (Rumb.) Nannf., which is usually associated with the bark beetle Ips sexdentatus Boern. Well-watered, nonpruned trees served as controls. Predawn needle water potential reached -2.5 MPa and net CO2 assimilation rates were reduced to almost zero during each water stress episode. The length of the reaction zones around inoculation points reached 3-4 cm after 3 weeks. It was higher during Spring than during Autumn. Impact of water stress on the length of the reaction zone was very limited and independent of the number of drought episodes that had been imposed prior to inoculation. The only visible change was a slight decrease when the inoculation was done during the period of maximum water stress intensity. Growth of the pathogen in the phloem was not affected by water stress. Correspondingly, pruning had no effect on either of these two parameters. Induced reaction zones accumulated monophenolic compounds that were undetectable in unwounded phloem. These included pinocembrin and pinosylvin and its monomethylether known to contribute to the defence against the fungus. Neither drought nor severe pruning induced any change in the nature or concentrations of these compounds in the unwounded phloem or in the reaction zone.

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