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.

The fine structure of the alimentary tract of third-stage larvae of Haemonchus placei and Trichostrongylus colubriformis

Parasitology ◽  
1971 ◽  
Vol 62 (3) ◽  
pp. 355-360 ◽  
Author(s):  
Kenneth Smith ◽  
Eric Harness
Keyword(s):  
Alimentary Tract ◽  
Buccal Cavity ◽  
Secretory Granules ◽  
Intestinal Cells ◽  
Similar Morphology ◽  
Gland Cells ◽  
Dense Bodies ◽  
Third Stage ◽  
General Organization ◽  
Haemonchus Placei

A comparative study was made of defined regions of the alimentary tract of third-stage larvae of T. colubriformis and H. placei. The general organization of the tract was similar in both nematodes. The mouth, buccal cavity and oesophagus were lined with cuticle. Muscle cells, apical cells and gland cells were present in the oesophagus. In both species the gland cells contained secretory granules of similar morphology. The lumen of the intestine was ill-defined and apparently nonfunctional. Dense bodies observed in the intestinal cells differed in the two species.We are grateful to Dr D. W. Brocklesby for his help and advice. We would also like to thank Dr D. L. Lee and Dr W. G. MacMillan for helpful discussions.

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 A comparative characteristic of fungal communities associated with Ips acuminatus in different regions of Ukraine

2019 ◽  
pp. 118-128
Author(s):  
Kateryna Davydenko
Keyword(s):  
Bark Beetle ◽  
Fungal Community ◽  
Bark Beetles ◽  
Diversity Index ◽  
Pathogenic Fungi ◽  
Pine Forest ◽  
Comparative Characteristic ◽  
Ophiostomatoid Fungi ◽  
Decay Fungi ◽  
Sphaeropsis Sapinea

Pine bark beetles are typically associated with complexes of fungi that could reveal different functional interaction. Thus, previously nonaggressive bark beetle Ips acuminatus is considering now to be among the most serious pests of pine forest in Ukraine and other European countries and vectored fungal community is very important to assess total harm of this bark beetle. The aim of this study was to reveal the vectored fungal community associated with the pine engraver beetle, I. acuminatus with special emphasis on pathogenic fungi for further evaluation of harm bark-beetle - fungi association for Ukrainian forest. In total, 288 adult beetles were collected from Scots pine trees at six different sites through Ukraine. DNA sequencing as fungal culturing from all beetles resulted in 1681 isolates and amplicons representing 42 fungal taxa. NCBI BLAST search revealed that the overall fungal community was composed of 94 species, of which 80.85% were Ascomycota, followed by Basidiomycota and unidentified fungal group, which accounted for 10.6% and 8.5 % of the total sequences, respectively. Among these, the most commonly detected fungi for pooling dataset were Sphaeropsis sapinea (23.6%), Cladosporium pini-ponderosae (19.44%), Ophiostoma ips (19.1%), Ophiostoma canum (19.1%) and Cladobotryum mycophilum (18.06%). In the pooled dataset of isolates and amplicons for each site, Shannon diversity indices ranged between 1.9 and 2.9 while Simpson diversity index varied between 0.69 and 0.89 indicating rich species diversity. In total twelve ophiostomatoid species were detected. All ophiostomatoid fungi were showing varying degrees of virulence and O. minus was the most aggressive fungus in previous studies. It is concluded that I. acuminatus vectors a species-rich fungal community including pathogens such as ophiostomatoid fungi, Sphaeropsis sapinea, different needle pathogens and wood decay fungi that seems to be very important for the assessment of threat of I. acuminatus to the pine forest in Ukraine.

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.

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 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.

scholarly journals Bacteria Belonging to Pseudomonas typographi sp. nov. from the Bark Beetle Ips typographus Have Genomic Potential to Aid in the Host Ecology

Insects ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 593
Author(s):  
Ezequiel Peral-Aranega ◽  
Zaki Saati-Santamaría ◽  
Miroslav Kolařik ◽  
Raúl Rivas ◽  
Paula García-Fraile
Keyword(s):  
Bark Beetle ◽  
Fungal Pathogens ◽  
Pathogenic Fungi ◽  
Gene Clusters ◽  
Ips Typographus ◽  
In Vitro Tests ◽  
Defense Compounds ◽  
Genes Encoding ◽  
Host Ecology

European Bark Beetle Ips typographus is a secondary pest that affects dead and weakened spruce trees (Picea genus). Under certain environmental conditions, it has massive outbreaks, resulting in the attacks of healthy trees, becoming a forest pest. It has been proposed that the bark beetle’s microbiome plays a key role in the insect’s ecology, providing nutrients, inhibiting pathogens, and degrading tree defense compounds, among other probable traits yet to be discovered. During a study of bacterial associates from I. typographus, we isolated three strains identified as Pseudomonas from different beetle life stages. A polyphasic taxonomical approach showed that they belong to a new species for which the name Pseudomonas typographi sp nov. is proposed. Genome sequences show their potential to hydrolyze wood compounds and synthesize several vitamins; screening for enzymes production was verified using PNP substrates. Assays in Petri dishes confirmed cellulose and xylan hydrolysis. Moreover, the genomes harbor genes encoding chitinases and gene clusters involved in the synthesis of secondary metabolites with antimicrobial potential. In vitro tests confirmed the capability of the three P. typographi strains to inhibit several Ips beetles’ pathogenic fungi. Altogether, these results suggest that P. typographi aids I. typographi nutrition and resistance to fungal pathogens.

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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