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.

scholarly journals Decline of pine forest in Ukraine with contribution from bark beetles: causes and trends

2019 ◽  
Author(s):  
В.Л. Мешкова
Keyword(s):  
Bark Beetle ◽  
Bark Beetles ◽  
Forest Health ◽  
Weather Conditions ◽  
Vegetation Period ◽  
Pine Forest ◽  
Laboratory Research ◽  
Natural Zones ◽  
Logging Residues ◽  
The Impact

Цель исследования обобщение опубликованных материалов и собственных данных об условиях возникновения очагов усыхания сосновых лесов и возможностях минимизации негативных последствий. Источники данных справочные материалы по структуре лесного фонда лесохозяйственных предприятий, состоянию лесов, характеристики погодных условий, результаты собственных полевых и лабораторных исследований (обследований насаждений, лабораторного выращивания короедов в отрезках ветвей, расчета популяционных показателей). За последние десятилетия изменились показатели тепла, влаги и континентальности, характеризующие лесоклиматические зоны, что влияет на состояние лесов и их восприимчивость к заселению короедами. Возрастание значения короедов рода Ips в комплексе стволовых вредителей сосновых лесов Украины связано с их поливольтинностью. Жуки отдельных поколений и фенологических групп вершинного короеда (Ips acuminatus) заселяют ослабленные деревья, ветровал и порубочные остатки в течение значительной части вегетационного периода. Доказана возможность развития трех поколений вершинного короеда в году в Харьковской области, однако быстрое высыхание порубочных остатков с повышением температуры может препятствовать завершению развития вредителя. Медленное высыхание заготовленной древесины и порубочных остатков в Полесье стало важной причиной интенсивного развития вспышек короедов в этом регионе. Предложено оценивать потенциальную площадь очагов усыхания в областях или природных зонах с учетом доли чистых сосновых насаждений и их возраста, а на уровне лесных массивов учитывать соседство выделов с вырубками. Отмечено несовершенство нормативной базы лесного хозяйства, препятствующее заготовке древесины в очагах короедного усыхания до того, как она превратится в дровяную. The goal of the research was integration of published and own data on the conditions for the occurrence of foci of pine forest decline and the prospects for mitigating this process. The data were obtained from reference materials on forest fund structure in forest enterprises, forest health, weather conditions, and the results of own field and laboratory research (forest inspections, laboratory rearing of the bark beetles in branches, and evaluation of population parameters). The main parameters of the forest climatic zones (heat, humidity, and continentality) have changed during the last decades. This affects forests health and their susceptibility to bark beetle colonization. The increase in the impact of Ips genus bark beetles in the complex of stem pests in pine forests of Ukraine is pertinent to their multivoltine development. Beetles of certain generations and phenological groups of pine engraver beetle (Ips acuminatus) colonize weakened and windthrown trees and logging residues during considerable part of vegetation period. A possibility of development of three generations per year has been proven for Ips acuminatus in Kharkov region (foreststeppe zone). However, quick drying of logging residues combined with increasing temperature may prevent the completion of pests development. Slow drying of harvested wood and logging residues in Polesie was an important reason for the intensive development of bark beetle outbreaks in the region. It was suggested to evaluate a potential area of drying forest in the regions or natural zones with consideration of the proportion of pure pine stands and their age. For certain forest stands, the proximity of every plot to clearcuts of the last two years must be taken into account. The flaws of forestry regulatory legislation are noted. These flaws prevent timely harvesting of timber in the bark beetles foci before this timber turns into firewood.

scholarly journals Fungal Communities Vectored by Ips sexdentatus in Declining Pinus sylvestris in Ukraine: Focus on Occurrence and Pathogenicity of Ophiostomatoid Species

Insects ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1119
Author(s):  
Kateryna Davydenko ◽  
Rimvydas Vasaitis ◽  
Malin Elfstrand ◽  
Denys Baturkin ◽  
Valentyna Meshkova ◽  
...  
Keyword(s):  
Pinus Sylvestris ◽  
Bark Beetle ◽  
Fungal Community ◽  
Direct Sequencing ◽  
Fungal Communities ◽  
Ophiostomatoid Fungi ◽  
Induced Stress ◽  
Tree Dieback ◽  
Pathogenicity Tests ◽  
Ips Sexdentatus

Drought-induced stress and attacks by bark beetle Ips sexdentatus currently result in a massive dieback of Pinus sylvestris in eastern Ukraine. Limited and fragmented knowledge is available on fungi vectored by the beetle and their roles in tree dieback. The aim was to investigate the fungal community vectored by I. sexdentatus and to test the pathogenicity of potentially aggressive species to P. sylvestris. Analysis of the fungal community was accomplished by combining different methods using insect, plant, and fungal material. The material consisted of 576 beetles and 96 infested wood samples collected from six sample plots within a 300 km radius in eastern Ukraine and subjected to fungal isolations and (beetles only) direct sequencing of ITS rDNA. Pathogenicity tests were undertaken by artificially inoculating three-to-four-year-old pine saplings with fungi. For the vector test, pine logs were exposed to pre-inoculated beetles. In all, 56 fungal taxa were detected, 8 exclusively by isolation, and 13 exclusively by direct sequencing. Those included nine ophiostomatoids, five of which are newly reported as I. sexdentatus associates. Two ophiostomatoid fungi, which exhibited the highest pathogenicity, causing 100% dieback and mortality, represented genera Graphium and Leptographium. Exposure of logs to beetles resulted in ophiostomatoid infections. In conclusion, the study revealed numerous I. sexdentatus-vectored fungi, several of which include aggressive tree pathogens.

scholarly journals The Lessons of Scots Pine Forest Decline in Ukraine

2020 ◽  
Vol 3 (1) ◽  
pp. 28
Author(s):  
Valentyna Meshkova
Keyword(s):  
Scots Pine ◽  
Bark Beetle ◽  
Bark Beetles ◽  
Forest Decline ◽  
Pine Forest ◽  
Control Measures ◽  
Laboratory Research ◽  
Forest Zone ◽  
Pine Stands ◽  
Scots Pine Forest

The condition of Ukraine’s forests has deteriorated sharply since the 2009 drought. The area of Scots pine stands decline has increased 2.3 times. The purpose of the research is integrating published and own data on Scots pine forest decline with the contribution of bark beetles and pointing the ways for mitigating this process. The reference materials regarding the forest stands characteristics, forest health, weather, as well as the results of own field and laboratory research were the data sources. Ips acuminatus (Gyllenhal, 1827): Coleoptera: Curculionidae: Scolytinae was the first bark beetle to infest weakened stands. The predominant development Scots pine decline in Polesie (Forest zone) is associated with a large proportion of pure pine stands of the same age, untimely thinning, and relatively slow drying of felling residues, in which the bark beetle has time to complete its development. The relative density of stocking by itself is a less important risk factor than its sudden decrease. The algorithm for prediction of bark beetles’ foci spread was developed. It will help to upgrade the accuracy of prediction, to evaluate the area of survey and control measures against insect pests. Recommendations for improving the forestry regulatory framework have been developed.

Fungal associates of five bark beetle species colonizing Norway spruce

1996 ◽  
Vol 26 (12) ◽  
pp. 2115-2122 ◽  
Author(s):  
Paal Krokene ◽  
Halvor Solheim
Keyword(s):  
Norway Spruce ◽  
Bark Beetle ◽  
Bark Beetles ◽  
Pathogenic Fungus ◽  
Pathogenic Fungi ◽  
Beetle Species ◽  
Low Frequencies ◽  
Blue Stain Fungi ◽  
Blue Stain ◽  
Fungal Associates

Fungi associated with five bark beetle species colonizing Norway spruce (Piceaabies (L.) Karst.) were isolated from beetle-inoculated logs. Ipstypographus L., an aggressive tree-killing bark beetle, was associated with a different range of blue-stain fungi than the nonaggressive Pityogeneschalcographus L., Polygraphuspoligraphus L., and Hylurgopspalliatus Gyll. The flora of the nonaggressive Ipsduplicatus Sahib. was similar to that of I. typographus. The pathogenic fungus Ceratocystispolonica (Siem.) C. Moreau, and other blue-stain fungi, were isolated in high frequency from inoculations with both Ips species. Pathogenic blue-stain fungi were absent, or isolated in low frequencies, from inoculations with the other nonaggressive beetle species. With the exception of I. duplicatus, these results support the hypothesis that aggressive bark beetles carry more pathogenic blue-stain fungi than other bark beetles and indicate that pathogenic fungi are important for aggressive bark beetles to kill trees.

scholarly journals Ophiostomatoid fungi vectored by bark beetles and colonizing trees of Pinus sylvestris in Sumy region (Ukraine)

2020 ◽  
pp. 22-29
Author(s):  
Kateryna Davydenko ◽  
Denys Baturkin
Keyword(s):  
Pinus Sylvestris ◽  
Scots Pine ◽  
Bark Beetle ◽  
Dna Sequences ◽  
Bark Beetles ◽  
Forest Damage ◽  
Ophiostomatoid Fungi ◽  
Primary Role ◽  
Pine Seedlings ◽  
Pine Trees

K. Davydenko[1], D. Baturkin[2] Intensive mortality of Pinus sylvestris trees has recently been observed in the Sumy region in eastern Ukraine. There are two pine bark beetle species (Ips acuminatus and Ips sexdentatus), which spread resulted in considerable forest damage in Ukraine. The study of ophiostomatoid fungi vectored by bark beetles is very important to assess total harm of these insects. Therefore, the aim of our research was i) to identify ophiostomatoid fungi associated with weakened and dying Scots pine trees infested by bark beetles in the Sumy region; ii) to test the pathogenicity of these ophiostomatoid fungi to evaluate their potential threat to Scots pine. The fungi were isolated from bark beetle galleries and identified based on morphological properties and DNA sequences. In total, eight ophiostomatoid fungi (Graphium sp., Grosmannia sp.1, Ophiostoma bicolor, O. ips, O. canum, O. piceae, O. minus, Ophiostoma sp.1) were isolated from Scots pine trees infested by bark beetles. Scots pine seedlings were inoculated with eight fungi and sterile medium (control) to evaluate their pathogenicity. The inoculated seedlings were examined finally in 6 month after inoculation. Inoculation with O. minus produced significantly largest lesions and only this fungus caused mortality of pine seedlings. In total, all eight fungal species inoculated caused resin exudation and staining the bark around inoculations in Scots pine seedlings and five fungi caused different rate of seedlings decline. The size of stained sapwood was also greater following O. minus inoculations than other fungi or the control. All ophiostomatoid fungi caused significantly longer necrotic lesions and more occlusions in the sapwood than the controls. Therefore, based on the ability of various ophiostomatoid fungi to weaken and kill pine seedlings and stain sapwood, O. minus was the most dangerous species for Scots pine trees, followed by Graphium sp. and Ophiostoma sp.1. The occurrence of ophiostmatoid fungi in the sapwood of Scots pine is consistent with the concept of their primary role in the colonization of the fresh sapwood of trees in the succession of microorganisms during wood decay.    

scholarly journals What Happens to Wood after a Tree Is Attacked by a Bark Beetle?

Forests ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1163
Author(s):  
Štěpán Hýsek ◽  
Radim Löwe ◽  
Marek Turčáni
Keyword(s):  
Mechanical Properties ◽  
Bark Beetle ◽  
Bark Beetles ◽  
Wood Decay ◽  
Physical And Mechanical Properties ◽  
Brown Rot ◽  
White Rot ◽  
Modulus Of Rupture ◽  
Tree Bark ◽  
Decay Fungi

Advancing climate change is affecting the health and vitality of forests in many parts of the world. Europe is currently facing spruce bark beetle outbreaks, which are most often caused by wind disturbances, hot summers, or lack of rainfall and are having a massive economic impact on the forestry sector. The aim of this research article was to summarize current scientific knowledge about the structure and physical and mechanical properties of wood from bark beetle-attacked trees. Spruce stands are attacked by a number of beetles, of which Ips typographus is the most common and widespread in Central Europe. When attacking a tree, bark beetles introduce ophiostomatoid fungi into the tree, which then have a greater effect on the properties of the wood than the beetles themselves. Fungal hyphae grow through the lumina of wood cells and spread between individual cells through pits. Both white rot and brown rot fungi are associated with enzymatic degradation of lignin or holocellulose, which is subsequently reflected in the change of the physical and mechanical properties of wood. Wood-decay fungi that colonize wood after infestation of a tree with bark beetles can cause significant changes in the structure and properties of the wood, and these changes are predominantly negative, in the form of reducing modulus of rupture, modulus of elasticity, discolouration, or, over time, weight loss. In certain specific examples, a reduction in energy consumption for the production of wood particles from beetle-attacked trees, or an increase in surface free energy due to wood infestation by staining fungi in order to achieve better adhesion of paints or glues, can be evaluated positively.

scholarly journals Fungal Communities Associated with Bark Beetles in Pinus radiata Plantations in Northern Spain Affected by Pine Pitch Canker, with Special Focus on Fusarium Species

Forests ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 698 ◽  
Author(s):  
Diana Bezos ◽  
Pablo Martínez-Álvarez ◽  
Antonio Sanz-Ros ◽  
Jorge Martín-García ◽  
M. Fernandez ◽  
...  
Keyword(s):  
Bark Beetle ◽  
Pinus Radiata ◽  
Bark Beetles ◽  
Fusarium Species ◽  
Pathogenic Fungi ◽  
Fungal Communities ◽  
Special Focus ◽  
Pitch Canker ◽  
Fusarium Circinatum ◽  
Northern Spain

Fusarium spp., as well as other endophytic or pathogenic fungi that form communities, have been reported to be phoretically associated with bark beetles (Coleoptera; Scolytinae) worldwide. This applies to Fusarium circinatum Nirenberg and O’Donnell, the causal agent of pine pitch canker (PPC), which threatens Pinus radiata D. Don plantations in northern Spain. The main objective of this study was to study the fungal communities associated with bark beetles and their galleries in stands affected by PPC, with special attention given to Fusarium species. Funnel traps and logs were placed in a P. radiata plot known to be affected by F. circinatum. The traps were baited with different attractants: four with (E)-pityol and six with ethanol and α-Pinene. In addition, fresh green shoots with Tomicus piniperda L. feeding galleries were collected from the ground in 25 P. radiata plots affected by PPC. Extracts of whole insects and gallery tissues were plated on agar medium to isolate and identify the associated fungi. A total of 24 different fungal species were isolated from the bark beetle galleries constructed in logs and shoots, while 18 were isolated from the insect exoskeletons. Ten different Fusarium species were isolated from tissue and insects. Fusarium circinatum was isolated from bark beetle exoskeletons (1.05% of the Pityophthorus pubescens Marsham specimens harboured F. circinatum) and from the galleries (3.5% of the T. piniperda feeding galleries harboured the pathogen). The findings provide information about the fungal communities associated with bark beetles in P. radiata stands in northern Spain.

Two new Ophiostoma species lacking conidial states isolated from bark beetles and bark beetle-infested Abies species in Japan

2006 ◽  
Vol 84 (2) ◽  
pp. 282-293 ◽  
Author(s):  
Nobuaki Ohtaka ◽  
Hayato Masuya ◽  
Yuichi Yamaoka ◽  
Shigeru Kaneko
Keyword(s):  
Molecular Analysis ◽  
Bark Beetle ◽  
Dna Sequences ◽  
Bark Beetles ◽  
Ophiostomatoid Fungi ◽  
Conidial Stage

Two ophiostomatoid fungi without conidiophores and conidia were isolated from bark beetles and bark beetle-infested Abies spp. The teleomorph characters were similar to species of Ophiostoma, but the absence of the conidial stage hampered their exact generic assignment. Detailed morphological observations and molecular analysis clarified their generic affiliation. Consequently, they were placed in the genus Ophiostoma , but their morphology and DNA sequences did not coincide with any other species of Ophiostoma. Here, we propose these two species as Ophiostoma aoshimae sp. nov. and Ophiostoma rectangulosporium sp. nov. The former species is characterized by perithecial necks ornamented with projections and ellipsoid to oblong ascospores, and the latter species is characterized by perithecial necks ornamented with rectangular ascospores and white colonies.

scholarly journals Diversity and Biocontrol Potential of Cultivable Endophytic Bacteria Associated with Halophytes from the West Aral Sea Basin

2021 ◽  
Vol 9 (7) ◽  
pp. 1448
Author(s):  
Lei Gao ◽  
Jinbiao Ma ◽  
Yonghong Liu ◽  
Yin Huang ◽  
Osama Abdalla Abdelshafy Mohamad ◽  
...  
Keyword(s):  
Endophytic Bacteria ◽  
Diversity Index ◽  
Pathogenic Fungi ◽  
Significant Inhibition ◽  
Isolation Effect ◽  
Aral Sea ◽  
Rrna Gene ◽  
Bacterial Isolates ◽  
Aral Sea Basin ◽  
Soil Borne Pathogens

Endophytes associated with halophytes may contribute to the host’s adaptation to adverse environmental conditions through improving their stress tolerance and protecting them from various soil-borne pathogens. In this study, the diversity and antifungal activity of endophytic bacteria associated with halophytic samples growing on the shore of the western Aral Sea in Uzbekistan were investigated. The endophytic bacteria were isolated from the nine halophytic samples by using the culture-dependent method and identified according to their 16S rRNA gene sequences. The screening of endophytic bacterial isolates with the ability to inhibit pathogenic fungi was completed by the plate confrontation method. A total of 289 endophytic bacterial isolates were isolated from the nine halophytes, and they belong to Firmicutes, Actinobacteria, and Proteobacteria. The predominant genera of the isolated endophytic bacteria were Bacillus, Staphylococcus, and Streptomyces, accounting for 38.5%, 24.7%, and 12.5% of the total number of isolates, respectively. The comparative analysis indicated that the isolation effect was better for the sample S8, with the highest diversity and richness indices. The diversity index of the sample S7 was the lowest, while the richness index of samples S5 and S6 was the lowest. By comparing the isolation effect of 12 different media, it was found that the M7 medium had the best performance for isolating endophytic bacteria associated with halophytes in the western Aral Sea Basin. In addition, the results showed that only a few isolates have the ability to produce ex-enzymes, and eight and four endophytic bacterial isolates exhibited significant inhibition to the growth of Valsa mali and Verticillium dahlia, respectively. The results of this study indicated that halophytes are an important source for the selection of microbes that may protect plant from soil-borne pathogens.

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