scholarly journals Pine engraver beetle Ips acuminatus as a potential vector of Sphaeropsis sapinea

2020 ◽  
pp. 149-156
Author(s):  
K. V. Davydenko ◽  
D. O. Baturkin
Keyword(s):  
Bark Beetle ◽  
Pathogenic Fungus ◽  
Opportunistic Pathogen ◽  
Potential Vector ◽  
Pine Engraver ◽  
Sphaeropsis Sapinea ◽  
Pine Engraver Beetle

The pine engraver beetle Ips acuminatus Gyll. is a potential vector of the Sphaeropsis tip blight pathogen according to Leach’s postulates. The specimens of I. acuminatus were associated with numerous fungi species, namely Sphaeropsis sapinea (Fr.) Dyko & B. Sutton and ophiostomatoid species. The association between opportunistic pathogen S. sapinea and I. acuminatus has been confirmed for 62.9 % of all branches (44 % of needle samples and 82 % of wood samples). The presence of S. sapinea in the galleries and on the surface of the beetle indicates that I. acuminatus may transport the pathogen and later introduce it into healthy trees. The bark beetle can transfer pathogenic fungus during maturation feeding on the shoots of healthy pine crowns and into the branches during making galleries.

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.

scholarly journals Life cycle of the pathogenic fungus Sphaeropsis sapinea Dyko & Sutton

2003 ◽  
pp. 141-156 ◽  
Author(s):  
Tanja Milijasevic
Keyword(s):  
Life Cycle ◽  
Pathogenic Fungus ◽  
Critical Time ◽  
Parasitic Fungus ◽  
Male And Female ◽  
Time Of Infection ◽  
Sphaeropsis Sapinea ◽  
Second Year ◽  
Female Flowers

The study of the parasitic fungus Sphaeropsis sapinea life cycle shows that the conidia disseminate most massively during the period April-May, i. e. during the critical time of infection, but also during the period June-August. Infection can occur through the buds in the spring, before their flushing, but also in the summer of the year of their development. Infection occurs most frequently through the bark of the young shoots, because of which they die while needle infections mostly lead to the so-called localized infections. Both male and female flowers can be infected, as well as the current-year and second-year cones. In some cases this fungus can behave as a latent parasite, i. e. endophyte.

scholarly journals Loss of Allergen 1 Confers a Hypervirulent Phenotype That Resembles Mucoid Switch Variants of Cryptococcus neoformans

2008 ◽  
Vol 77 (1) ◽  
pp. 128-140 ◽  
Author(s):  
Neena Jain ◽  
Li Li ◽  
Ye-Ping Hsueh ◽  
Abraham Guerrero ◽  
Joseph Heitman ◽  
...  
Keyword(s):  
Intracranial Pressure ◽  
Cryptococcus Neoformans ◽  
Gene Function ◽  
Pathogenic Fungus ◽  
Opportunistic Pathogen ◽  
Phenotypic Switching ◽  
Elevated Intracranial Pressure ◽  
Macrophage Phagocytosis ◽  
Switch Variant

ABSTRACT Microbial survival in a host is usually dependent on the ability of a pathogen to undergo changes that promote escape from host defense mechanisms. The human-pathogenic fungus Cryptococcus neoformans undergoes phenotypic switching in vivo that promotes persistence in tissue. By microarray and real-time PCR analyses, the allergen 1 gene (ALL1) was found to be downregulated in the hypervirulent mucoid switch variant, both during logarithmic growth and during intracellular growth in macrophages. The ALL1 gene encodes a small cytoplasmic protein that is involved in capsule formation. Growth of an all1Δ gene deletion mutant was normal. Similar to cells of the mucoid switch variant, all1Δ cells produced a larger polysaccharide capsule than cells of the smooth parent and the complemented strain produced, and the enlarged capsule inhibited macrophage phagocytosis. The mutant exhibited a modest defect in capsule induction compared to all of the other variants. In animal models the phenotype of the all1Δ mutant mimicked the hypervirulent phenotype of the mucoid switch variant, which is characterized by decreased host survival and elevated intracranial pressure. Decreased survival is likely the result of both an ineffective cell-mediated immune response and impaired phagocytosis by macrophages. Consequently, we concluded that, unlike loss of most virulence-associated genes, where loss of gene function results in attenuated virulence, loss of the ALL1 gene enhances virulence by altering the host-pathogen interaction and thereby impairing clearance. Our data identified the first cryptococcal gene associated with elevated intracranial pressure and support the hypothesis that an environmental opportunistic pathogen has modified its virulence in vivo by epigenetic downregulation of gene function.

Gut microbiota in an invasive bark beetle infected by a pathogenic fungus accelerates beetle mortality

2018 ◽  
Vol 92 (1) ◽  
pp. 343-351 ◽  
Author(s):  
Letian Xu ◽  
Jundan Deng ◽  
Fangyuan Zhou ◽  
Chihang Cheng ◽  
Longwa Zhang ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Bark Beetle ◽  
Pathogenic Fungus

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.

Responses of Ips pini (Say), Pityogenes knechteli Swaine and Associated Beetles (Coleoptera) to Host Monoterpenes in Stands of Lodgepole Pine

2003 ◽  
Vol 38 (4) ◽  
pp. 602-611 ◽  
Author(s):  
Daniel R. Miller ◽  
John H. Borden
Keyword(s):  
Bark Beetle ◽  
Bark Beetles ◽  
Mountain Pine Beetle ◽  
Lodgepole Pine ◽  
Behavioral Responses ◽  
Ips Pini ◽  
Host Volatiles ◽  
Pine Engraver ◽  
Pine Beetle

We conducted seven experiments in stands of mature lodgepole pine in southern British Columbia to elucidate the role of host volatiles in the semiochemical ecology of the pine engraver, Ips pini (Say) (Coleoptera: Scolytidae), with particular reference to the behavioral responses of predators and competing species of bark beetles. Our results demonstrated that the attraction of Ips pini and the bark beetle predators Lasconotus complex LeConte (Colydiidae), Thanasimus undatulus (Say) (Cleridae) and a Corticeus sp. (Tenebrionidae) were increased by 3-carene. In contrast, attraction of the bark beetle Pityogenes knechteli Swaine (Scolytidae) to ipsdienol was interrupted by 3-carene and α-pinene. Attraction of L. complex to ipsdienol was increased by γ-terpinene, a compound attractive to the mountain pine beetle, Dendroctonus ponderosae Hopkins (Scolytidae). Terpinolene interrupted the attraction of I. pini to ipsdienol.

Acoustic communication in the pine engraver bark beetle: do signals vary between behavioural contexts?

2017 ◽  
Vol 43 (1) ◽  
pp. 30-41 ◽  
Author(s):  
Andras Dobai ◽  
Senthurran Sivalinghem ◽  
Raul N.C. Guedes ◽  
Jayne E. Yack
Keyword(s):  
Bark Beetle ◽  
Acoustic Communication ◽  
Pine Engraver
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