scholarly journals Fungal Diversity in Multiple Post-harvest Aged Red Pine Stumps and Their Potential Influence on Heterobasidion Root Rot in Managed Stands Across Minnesota

2021 ◽  
Vol 2 ◽  
Author(s):  
Eric C. Otto ◽  
Benjamin W. Held ◽  
Trevor J. Gould ◽  
Robert A. Blanchette
Keyword(s):  
Biological Control Agent ◽  
Illumina Miseq ◽  
Diversity Indices ◽  
Control Agent ◽  
Red Pine ◽  
Similar Species ◽  
Native Range ◽  
Change Over Time ◽  
Phlebiopsis Gigantea ◽  
Over Time

Thinning operations that occur in managed red pine (Pinus resinosa) stands, create tree stumps that can serve as a habitat for fungi, especially Heterobasidion irregulare, the cause of a serious root disease. Different fungi can colonize stumps early and the community of fungi can change over time as initial fungal species become replaced. Samples were collected from both the native and non-native range of red pine from stumps that were cut at different time periods. Stumps that were harvested at 0–1, 2–3, 5–6, and 10–12 years before sampling were used to provide data on the diversity of fungi that colonize tree stumps and how these communities can change over time as well as how they influence colonization of H. irregulare. Traditional culturing methods and Illumina MiSeq sequencing were used to identify the fungi in the samples. Of particular interest was Phlebiopsis gigantea, which can colonize cut stumps and prevent H. irregulare from becoming established. Overall, P. gigantea was the most abundant fungus isolated and sequenced via Illumina MiSeq. Results show that Phlebiopsis gigantea was isolated from 90% of all stumps sampled for sites harvested within 3 years of sampling in the native range of red pine compared to 33% in the non-native range. For Illumina MiSeq, 5,940 total amplicon sequence variants (ASVs) were detected. P. gigantea represented 14% of the total reads and composed 19% of the reads in the native range and 8% in non-native range of red pine. Furthermore, P. gigantea represented 38% of the reads for stumps that were harvested within 3 years of sampling in the native range of red pine compared to 14% in the non-native range. These results help demonstrate that a higher amount of P. gigantea is present in the native range of red pine and could be acting as a native biological control agent. Additional fungi, including Resinicium bicolor, Hypochnicium cremicolor, Leptographium spp., and others identified at different cutting times are also discussed. Finally, different diversity indices revealed similar, but slightly higher diversity for southern sites via Shannon and Simpson Diversity indices. Beta diversity demonstrated a similar species composition in stumps harvested at different times with these stumps being grouped together based on harvesting years.

scholarly journals Efficacy of two Phlebiopsis gigantea formulations in preventing Heterobasidion irregulare colonization of red pine stumps in eastern Canada

2013 ◽  
Vol 93 (1) ◽  
pp. 25-31 ◽  
Author(s):  
Michael T. Dumas ◽  
Gaston Laflamme
Keyword(s):  
Tree Mortality ◽  
Control Method ◽  
Biological Control Agent ◽  
Control Agent ◽  
Fungal Species ◽  
Red Pine ◽  
Pine Plantations ◽  
Eastern Canada ◽  
Phlebiopsis Gigantea ◽  
Heterobasidion Irregulare

Heterobasidion irregulare is the scientific name for the North American fungal species that was previously known as H. annosum (P-type) and Fomes annosus. In eastern Canada, the pathogen is found mainly in red pine plantations in southern Ontario and Quebec, where it causes tree mortality. There is no registered control method currently available for this disease in Canada. Phlebiopsis gigantea is a saprophytic basidiomycete successfully used and registered as a biological control agent in several European countries. In order to register a control product in Canada, its efficacy must be demonstrated under field conditions. Trials were performed with two Canadian isolates of P. gigantea in four red pine plantations in Ontario. The mean diameters of treated stumps ranged from 29 to 35 cm. After 2 mo, all 238 stumps treated were free of disease, while 12% of the 120 untreated stumps were colonized by the pathogen. The two formulations without P. gigantea did not prevent the colonization of the stumps by either P. gigantea or H. irregulare. These results show that the two Canadian isolates of P. gigantea can prevent colonization of red pine stumps by H. irregulare and provide support for the registration of P. gigantea as a biocontrol agent in eastern Canada.

Population Cycles of the Larkspur Mirid (Heteroptera: Miridae)

2000 ◽  
Vol 35 (4) ◽  
pp. 483-489 ◽  
Author(s):  
Michael H. Ralphs ◽  
Walker A. Jones
Keyword(s):  
Biological Control Agent ◽  
Population Cycles ◽  
Control Agent ◽  
Feeding Damage ◽  
Delphinium Barbeyi ◽  
Weather Patterns ◽  
Tall Larkspur ◽  
Low Levels ◽  
Extent Of Damage ◽  
Over Time

The larkspur mirid, Hoplomachus affiguratus Uhler, has been proposed as a biological control agent to damage tall larkspur, Delphinium barbeyi (L.) Huth, to prevent cattle from grazing it and becoming poisoned. The objective of this study was to monitor mirid populations and feeding damage to larkspur over time and determine if its population cycles are related to specific weather patterns. Individual larkspur plants were marked and the extent of damage estimated at 5 locations on 3 National Forests in Utah and Colorado. In years when mirid populations were high, damage to larkspur leaves ranged from 50 to 100% and greater than 75% of flowering heads aborted. In years and locations when its population was down, damage was minimal. The amount of larkspur damage was negatively correlated with the previous year's total precipitation and the previous September precipitation (r = −0.68 to −83) and was positively correlated with July and August temperature the previous year (r = 0.61 to 0.75). When mirid populations are high, damage levels appear to be sufficient to deter cattle grazing, but low levels of damage at the bottom of the cycle will likely not deter grazing.

scholarly journals Diapause behaviour of Zygogramma bicolorata (Coleoptera: Chrysomelidae), a biological control agent for Parthenium hysterophorus (Asteraceae), in Bangalore, India

1993 ◽  
Vol 83 (3) ◽  
pp. 383-388 ◽  
Author(s):  
K. P. Jayanth ◽  
Geetha Bali
Keyword(s):  
Biological Control ◽  
Biological Control Agent ◽  
Extended Period ◽  
Control Agent ◽  
Parthenium Hysterophorus ◽  
Continuous Exposure ◽  
Zygogramma Bicolorata ◽  
Before And After ◽  
Summer Temperatures ◽  
Over Time

AbstractZygogramma bicolorata Pallister was introduced for biological control trials against the weed Parthenium hysterophorus (Asteraceae) in India. The insect entered diapause over an extended period of time between July and December in Bangalore. Diapausing adults burrowed into the soil, and emerged in May–June with the commencement of monsoon rains. Percentage diapause increased over time, peaking at 72% during November. Non-diapausing adults were capable of breeding, under laboratory conditions, during the winter. Some adults bred both before and after diapause, during two consecutive years. Soil moisture played an important role in providing the conditions for burrowing or emerging from the diapause chambers. The studies also showed that diapausing adults had to be exposed to the high summer temperatures, for termination of the diapause. It was possible to break diapause by continuous exposure to 30°C, 35°C and 40°C for 22 days, nine days and 10 hours, respectively, during February–March, about three months after its inception. This method can be used to initiate mass multiplication for carrying out releases early in the season.

‘Rhyzobius ventrails’ (Coleoptera: Coccinellidae), its constituent species, and their taxonomy and historical roles in biological control

1981 ◽  
Vol 71 (1) ◽  
pp. 19-32 ◽  
Author(s):  
R. D. Pope
Keyword(s):  
Nineteenth Century ◽  
Biological Control ◽  
Biological Control Agent ◽  
Scale Insect ◽  
Control Agent ◽  
Distribution Data ◽  
Similar Species ◽  
Control Scale ◽  
Constituent Species ◽  
Insect Infestations

AbstractThe Rhyzobius (or Lindorus) ventralis frequently referred to in the literature of biological control is shown to be a mixture of two distinct, though similar, species. The origin of the confusion is traced to the nineteenth century searches in Australia for insects to control scale insect infestations on citrus and other crops in California. Adults of the two species are defined and illustrated, and a key is provided for their separation. Lectotypes are designated for R. ventralis (Erichs.), its synonym Scymnus restitutor Sharp and for S. halli Broun, newly synonymised with R. ventralis. A lectotype is designated for Platyomus forestieri Muls., the second species of the complex, here transferred to Rhyzobius, and for S. circularis Sharp, newly synonymised with R. forestieri. Distribution data for both species, based on actual specimens examined, are listed, and their Australian distribution is summarised in a map. Past usages of ‘ R. ventralis’ as a biological control agent are reviewed in the light of the revised taxonomy. The taxonomy and nomenclature of Rhyzobius Stephens is discussed in order to establish the correct generic placement of and binomina for R. ventralis and R. forestieri.

scholarly journals Microbial Landscape of the Grapevine Endosphere in the Context of Pierce’s Disease

2017 ◽  
Vol 1 (3) ◽  
pp. 138-149 ◽  
Author(s):  
Elizabeth Deyett ◽  
M. Caroline Roper ◽  
Paul Ruegger ◽  
Jiue-In Yang ◽  
James Borneman ◽  
...  
Keyword(s):  
Microbial Community ◽  
Biological Control Agent ◽  
Vascular Diseases ◽  
Illumina Miseq ◽  
Control Agent ◽  
Pierce's Disease ◽  
Achromobacter Xylosoxidans ◽  
Pierce’S Disease ◽  
Fungal Microbiome ◽  
Disease Pressure

Microbial community structure and composition in the plant vascular endosphere has not been studied extensively especially in the context of vascular diseases. Pierce’s disease (PD) of grapevine is caused by Xylella fastidiosa, a xylem-limited bacterium. In PD-impacted vineyards, there are observations of vines that remain asymptomatic despite being under high disease pressure. Because these vines are clonal, we hypothesized that the microbial community inhabiting the grapevine vascular endosphere is a major contributor to the disease escape phenotype. We used a next-generation sequencing Illumina MiSeq-based platform to characterize the bacterial and fungal microbiome residing in the cane endosphere of grapevine that displayed severely symptomatic, to mildly symptomatic or asymptomatic disease phenotypes. Our results provide evidence that the endophytic grapevine microbial community is composed primarily of Proteobacteria and Ascomycota with Pseudomonodales and Pleosporales as the main bacterial and fungal orders, respectively. Endophytic Pseudomonas fluorescens and Achromobacter xylosoxidans showed significant negative correlations with X. fastidiosa titer. Our data suggest that the clustering of bacterial communities appeared to be driven by the abundance of both P. fluorescens and X. fastidiosa. P. fluorescens emerged as a potential driver of the disease-escape phenotype and a promising biological control agent of PD.

scholarly journals Comparative Efficacy of State-of-the-Art and New Biological Stump Treatments in Forests Infested by the Native and the Alien Invasive Heterobasidion Species Present in Europe

Pathogens ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1272
Author(s):  
Martina Pellicciaro ◽  
Guglielmo Lione ◽  
Silvia Ongaro ◽  
Paolo Gonthier
Keyword(s):  
North American ◽  
Fungal Pathogens ◽  
State Of The Art ◽  
Biological Control Agent ◽  
Abies Alba ◽  
Control Agent ◽  
Heterobasidion Annosum ◽  
The North ◽  
Phlebiopsis Gigantea ◽  
New Treatments

The Heterobasidion annosum species complex includes major fungal pathogens of conifers worldwide. State-of-the-art preventative stump treatments with urea or with commercial formulations of the fungal biological control agent Phlebiopsis gigantea (i.e., Rotstop®) may become no longer available or are not approved for use in many areas of Europe infested by the three native Heterobasidion species and by the North American invasive H. irregulare, making the development of new treatments timely. The efficacy of Proradix® (based on Pseudomonas protegens strain DSMZ 13134), the cell-free filtrate (CFF) of the same bacterium, a strain of P. gigantea (MUT 6212) collected in the invasion area of H. irregulare in Italy, Rotstop®, and urea was comparatively investigated on a total of 542 stumps of Abies alba, Picea abies, Pinus pinea, and P. sylvestris in forest stands infested by the host-associated Heterobasidion species. Additionally, 139 logs of P. pinea were also treated. Results support the good performances of Rotstop®, and especially of urea against the native Heterobasidion species on stumps of their preferential hosts and, for the first time, towards the invasive North American H. irregulare on stumps of P. pinea. In some experiments, the effectiveness of Proradix® and of the strain of P. gigantea was weak, whereas the CFF of P. protegens strain DSMZ 13134 performed as a valid alternative to urea and Rotstop®. The mechanism of action of this treatment hinges on antibiosis; therefore, further improvements could be possible by identifying the active molecules and/or by optimizing their production. Generally, the performance of the tested treatments is not correlated with the stump size.

Molecular comparisons of native range collections of Gadirtha fusca, a potential biological control agent of Chinese tallowtree

2018 ◽  
Vol 28 (8) ◽  
pp. 796-804 ◽  
Author(s):  
G. S. Wheeler ◽  
K. Dyer ◽  
E. Broggi ◽  
Jianqing Ding ◽  
Matthew Purcell ◽  
...  
Keyword(s):  
Biological Control ◽  
Biological Control Agent ◽  
Control Agent ◽  
Native Range
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