Geology topics

Kylle Roy

Publications and source records attributed to Kylle Roy.

14 recordsLinked to original sources

USGS2025

Temporal associations between ambrosia beetles and ʻōhiʻa (Metrosideros polymorpha) artificially inoculated with Ceratocystis lukuohia

Wood boring ambrosia beetles play a central role in the spread of Ceratocystis wilt of ‘ōhi‘a, a fungal disease caused by Ceratocystis lukuohia that kills the bioculturally important ‘ōhiʻa ( Metrosideros polymorpha ) tree. Beetles contribute to the spread of the disease by extruding fungus-infected wood particles (frass). Disease mitigation can benefit from knowledge of ambrosia beetle life-history and fungal survival in affected ‘ōhi‘a. We investigated temporal associations among tree death, the timing and duration of beetle attacks, and the persistence of viable C. lukuohia within intentionally infected (inoculated) ʻōhiʻa at three sites that approximate the elevational range of the disease on the Island of Hawaiʻi. Beetles most frequently attacked inoculated trees at the time when foliage first showed symptoms of infection (yellow leaves; n = 9) although some attacks were observed during earlier (green leaf; n = 3) and later (brown leaf; n = 3) stages of symptom progression. On average, beetles initiated new attacks for nearly one year after trees were inoculated. We tracked active galleries of Xyleborinus saxesenii , Xyleborus ferrugineus and Xyleborus simillimus and found they produced frass with viable C. lukuohia propagules for 122.8 ± 40.0, 275.8 ± 32.7 and 304.2 ± 53.4 days, respectively. Infected ʻōhiʻa felled from our mid-elevation site at the end of the study revealed viable fungal propagules and the presence of X. ferrugineus over two years after trees first appeared symptomatic of infection, suggesting that Ceratocystis wilt of ʻōhiʻa remains a threat to spread from infected trees long after trees succumb to the disease.

Hawaii↗

USGS2024

The efficacy of the semiochemical repellent verbenone to reduce ambrosia beetle attack on healthy and Ceratocystis-infested ‘ōhiʻa trees

The Ceratocystis fungal disease complex, rapid ʻōhiʻa death (ROD), has killed over one million ʻōhiʻa ( Metrosideros polymorpha ), the keystone tree species of Hawaiʻi. The causal fungi can be spread by invasive ambrosia beetles (Coleoptera: Curculionidae) through fungal inoculum found on their bodies and in the frass they produce. Thus, there is a critical need to manage beetle attack on ʻōhiʻa trees to curtail subsequent pathogen spread and disease development. In this experiment at Waiākea Forest Reserve, we tested the potential of the semiochemical repellent, verbenone, in a commercial formulation, to protect healthy and ROD-affected ʻōhiʻa from ambrosia beetle attack in each of the 2022 and 2023 field seasons. Landing rates of ambrosia beetles on healthy and diseased trees were quantified over 16 weeks each year, using sticky traps on ethanol-baited trees that also received either a low (72 g) or high (108 g) dose of verbenone or untreated controls. In addition, we used gas-chromatography mass-spectrometry (GC–MS) to measure verbenone emission over 16 weeks in 2022. We found that the low dose of verbenone is the most effective and economical application to reduce beetle landing on healthy ʻōhiʻa trees and the high dose may be needed to reduce attraction to diseased ʻōhiʻa. Despite a large decrease in verbenone emission levels by week eight, the low dose effectively reduced beetle captures on healthy trees for 14 weeks and the high dose reduced landing rates on diseased trees for 10–14 weeks. Our results indicate verbenone may significantly lower ambrosia beetle attack on ʻōhiʻa, and thus, lead to reduction in the spread of ROD.

Hawaii↗

USGS2023

The use of semiochemicals for attracting and repelling invasive ambrosia beetles (Coleoptera: Curculionidae) in ʻōhiʻa (Metrosideros polymorpha) forests

Early detection of invasive species is critical for preventing ecological and economic damage and maintaining ecosystem health. In Hawaiʻi, a complex of generalist ambrosia beetle species in the tribe Xyleborini (Coleoptera: Scolytinae) are threatening the health and productivity of forests and crops due to their association with tree diseases such as rapid ʻōhiʻa death (ROD) and key agricultural commodities including coffee and macadamia. We conducted trapping experiments to determine the efficacy of semiochemicals to attract and repel Xyleborini ambrosia beetles within two ʻōhiʻa ( Metrosideros polymorpha ) forests on the Island of Hawaiʻi. We compared the attraction of beetles to 100% ethanol and a 1:1 mixture of ethanol: methanol at Waiākea Forest Reserve and ʻŌlaʻa Forest in Hawaiʻi Volcanoes National Park. In addition, we tested the extent to which verbenone and verbenone + methyl salicylate repellents (SPLAT® Verb and SPLAT® Beetle Guard, respectively) deterred beetles from baited traps at Waiākea Forest Reserve in two separate experiments. For all invasive ambrosia beetle species, including Xyleborinus saxesenii , Xyleborus affinis , Xyleborus ferrugineus , Xyleborus perforans, Xylosandrus compactus , and Xylosandrus crassiusculus , more beetles were captured in traps baited with 100% ethanol than 1:1 ethanol: methanol. Across all species, both repellents were effective, with fewer beetles captured in traps equipped with repellents. Our research demonstrates the utility of semiochemicals for attracting and repelling invasive ambrosia beetle species in Hawaiʻi, and the potential use of these tools for early detection and management strategies.

Hawaii↗

USGS2023

Ambrosia beetles (Coleoptera: Curculionidae) can directly transmit the fungal pathogens responsible for Rapid ʻŌhiʻa Death

The ecologically and culturally vital tree species, ʻōhiʻa lehua ( Metrosideros polymorpha ), is threatened by the fungal pathogens Ceratocystis lukuohia and Ceratocystis huliohia , the causal agents of the disease complex called Rapid ʻŌhiʻa Death (ROD). Four invasive ambrosia beetle (Coleoptera: Curculionidae: Scolytinae) species in the Xyleborini tribe colonize ROD Ceratocystis -infested ‘ōhiʻa and produce inoculum through their frass; however, the potential for direct transmission of the ROD fungi by these beetles was unknown. We fulfilled Leach's rules to support insect transmission of ROD by documenting the visitation of these ambrosia beetles to healthy ‘ōhiʻa trees, culturing C. lukuohia and C. huliohia from the ROD-associated beetles using three different collection methods at multiple study sites, and challenging healthy ʻōhiʻa seedlings with beetles that were exposed to both C. lukuohia and C. huliohia cultures. We documented all four invasive ROD-associated ambrosia beetle species including Xyleborinus saxesenii , Xyleborus affinis , Xyleborus ferrugineus , and Xyleborus perforans to regularly visit healthy ʻōhiʻa trees on sticky traps. Viable Ceratocystis propagules were isolated from all species, and C. lukuohia was most commonly isolated of the two ROD-causing fungi. Consistently across all collection techniques, ROD Ceratocystis spp. were detected on just under 3% of all assayed beetles, with the highest detection rate from X. affinis . All four beetle species were capable of directly transmitting both pathogens to healthy ʻōhiʻa seedlings with a high rate of transfer. Ceratocystis spp. are highly virulent pathogens in trees, and a single inoculation can result in tree death, therefore any direct transmission is a cause for concern. After meeting the criteria of Leach's rules, we propose that Xi. saxesenii , X. affinis , X. ferrugineus , and X. perforans are vectors of C. lukuohia and C. huliohia , particularly in areas of high ROD pressure and tree stress.

Hawaii↗

USGS2023

Ambrosia beetles (Coleoptera: Curculionidae: Scolytinae and Platypodinae) associated with rapid ohia death and mixed Metrosideros polymorpha forests on the Island of Kauai, Hawaii

Xyleborini (Coleoptera: Curculionidae) beetles on the island of Kauaʻi, Hawaiʻi, are of interest due to their role in the fungal disease complex, rapid ʻōhiʻa death (ROD), and the unique radiation of endemic ambrosia beetles found across the Hawaiian archipelago. We investigated the status of RODassociated and native ambrosia beetles on Kauaʻi by rearing beetles from bolts collected from ROD-Ceratocystis infested ʻōhiʻa lehua (ʻōhiʻa; Metrosideros polymorpha) trees and trapping in mixed ʻōhiʻa forests. Beetles associated with ROD on Kauaʻi include Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xyleborus perforans, Xylosandrus crassiusculus, and Crossotarsus externedentatus. Xyleborus perforans was most abundant in ʻōhiʻa bolts followed by Xyleborus ferrugineus. From trap captures, we identified new island records of the native Xyleborus beetles including Xyleborus dubiosus, Xyleborus oahuensis, and Xyleborus tantalus. Xylosandrus crassiusculus was most abundant in traps. Additional work could contribute to understanding and mitigating the spread of ROD on Kauaʻi and to documenting the endemic Xyleborus beetles.

Hawaii↗

USGS2022

Environmental monitoring for invasive fungal pathogens of ʽŌhiʽa (Metrosideros polymorpha) on the Island of Hawaiʽi

The invasive rust Austropuccina psidii was detected in the Hawaiian Islands in 2005 and has become widely established throughout the archipelago in both native and introduced species of Myrtaceae. Initial predictions about the impacts of the fungus on native ʽōhiʽa lehua ( Metrosideros polymorpha ), a keystone native tree, have not materialized, but there is ongoing concern that introductions of new genotypes of the fungus could lead to widespread mortality with catastrophic effects on native ecosystems. By contrast, two recently emergent Ascomycete pathogens, Ceratocystis lukuohia ( Ceratocystis wilt of ‘ōhi‘a) and C. huliohia ( Ceratocystis canker of ‘ōhi‘a), collectively known to cause Rapid ʽŌhiʽa Death (ROD), are causing significant mortality in native forests on Hawaiʻi and Kauaʻi Islands, but pathways of spread are still incompletely understood. We used a network of passive environmental samplers for collecting windblown urediniospores of Austropuccina to evaluate the effectiveness of environmental monitoring to detect seasonal and landscape-scale differences in airborne propagules of this rust on Hawai`i Island. The samplers were also used to determine if windborn ambrosia beetle frass or spores of Ceratocystis can spread long distances. We found frequent detections and regional and seasonal differences in numbers of samplers that were positive for urediniospores of Austropuccinia , but little evidence of long-distance airborne dispersal of the ROD-causing fungi. The simple, inexpensive platform for sampling airborne fungal spores that we used may have value as a monitoring tool for detecting spread of airborne fungal pathogens, evaluating habitats for suitability for restoration efforts, and for detecting new pathogen introductions, particularly new Austropuccinia genotypes both in Hawaiʻi and other parts of the world.

Hawaii↗

USGS2022

Ceratocystis lukuohia-infested ambrosia beetle frass as inoculum for Ceratocystis wilt of ʻōhiʻa (Metrosideros polymorpha)

Metrosideros polymorpha (‘ōhi‘a) trees in Hawaiʻi are dying from two distinct diseases, collectively referred to as rapid ‘ōhi‘a death (ROD), caused by Ceratocystis lukuohia and Ceratocystis huliohia . Boring dust (frass) released when ambrosia beetles attack and colonize infected trees has been suspected as a transmission source. We sampled ambrosia beetle frass from six locations on Hawaiʻi Island and screened samples for Ceratocystis DNA and fungal viability. Ceratocystis DNA was detected in 79% of frass samples and 61% were viable. To assess the infectivity of C . lukuohia -colonized frass, M . polymorpha seedlings were wound-inoculated with frass in growth chamber trials. Wilt incidence was 40% in the first trial and 15% in the second. Frass particles naturally infested with C . lukuohia were treated with a cytoplasmic stain and microscopically examined; thick-walled chlamydospores were found in all samples. The chlamydospores appeared to be derived from aleurioconidia. Ceratocystis survival in frass was assessed in a baiting experiment conducted under varying environmental regimes; viability decreased with increasing temperature, frass age and decreasing humidity. After 6 months, 90% of the samples exhibited viable C . lukuohia at the lowest temperatures. Results confirmed that C . lukuohia chlamydospores are the fungal inoculum within ambrosia beetle frass and can induce wilt when introduced to M . polymorpha wounds. Although ambrosia beetles or other insects may serve as vectors, the present work supports the hypothesis that Ceratocystis species may be dispersed in frass, which can inform ongoing efforts to manage ROD across Hawaiʻi's native forests.

Hawaii↗

USGS2022

Rapid ʻŌhiʻa Death in Hawaiʻi

Ceratocystis lukuohia and Ceratocystis huliohia are two newly recognized fungi that have arrived in Hawai‘i and are causing a serious vascular wilt and canker disease, respectively, of ‘ōhi‘a trees ( Metrosideros polymorpha ), the most common and important tree species in Hawai‘i. Management of these diseases has presented challenges due to unique etiological aspects and the exceptionally pathogenic nature of one of these fungi ( C. lukuohia ) once it gains access to the tree’s vascular tissue. Careful study of the spread of the pathogens has resulted in an understanding of the role of ambrosia beetles and the frass they produce that carries the pathogen, as well as the wounding of trees by many different agents by which the pathogen can access and infect the vascular tissue. A variety control measures are being used. These include a state-of-the-art monitoring program to detect diseased and recently killed trees and molecular biology approaches that can confirm if a given tree was infected by Ceratocystis . Based on monitoring more than one million trees have been estimated as killed by the diseases to date. A major part of the program includes the deployment of a field crew that seeks out and fells large infected ‘ōhi‘a trees as these trees are the main source of most of the infective Ceratocystis -laden frass. Long-term control measures also include fencing of some forests to reduce the amount of wounding to ‘ōhi‘a trees by feral cattle and pigs that allows entry of the fungi and quarantine restrictions to ensure there will be no inter-island movement of the pathogens in ‘ōhi‘a products. Finally, methods are also being developed to restore ‘ōhi‘a forests affected by these diseases by determining effective regeneration practices and developing genetically resistant ‘ōhi‘a stock. Hawai‘i has an active extension program dedicated to providing information on how residents and visitors can contribute to protecting ‘ōhi‘a trees from these diseases. More than 500,000 people have participated in this program. Hawai‘i residents have a very deep appreciation for this tree species and do what they can to help prevent these diseases from destroying more of their most treasured tree species.

Hawai'i↗

USGS2021

Effectiveness of rapid 'ōhi'a death management strategies at a focal disease outbreak on Hawai'i Island

The ongoing spread of rapid ‘ōhi‘a death (ROD) in the Hawaiian Islands threatens the long-term sustainability of ‘ōhi‘a lehua (Metrosideros polymorpha) forests throughout the state. First identified in the Puna district of Hawai‘i Island in 2014, the disease caused by the novel fungi Ceratocystis lukuohia and Ceratocystis huliohia has now spread island-wide and was recently detected on Kaua‘i, O‘ahu, and Maui. The leading hypothesis for the spread of ROD is through airborne ambrosia beetle frass particles that contain viable Ceratocystis propagules, thus management efforts focus on containing this frass. At the time of this study (2017–2018), the Waipunalei site was the northernmost outbreak of ROD on Hawai‘i Island. The focal nature of the outbreak and accessibility of the location provided the opportunity to monitor the effectiveness of two types of proposed management methods to reduce the airborne spread of potentially infective ambrosia beetle frass: tree felling and insecticide treatments. We placed 23 passive environmental samplers (PES), which monitored for airborne frass and wood particles containing C. lukuohia and C. huliohia in a grid that spanned the outbreak area over 22 weeks. Cross-vane panel traps with 1:1 methanol:ethanol lures were attached to nine of the PES to document wood-boring ambrosia and cerambycid beetle populations during the latter three months of the study. Monitoring with PES began three weeks before management and continued for one month after the last infected trees were felled. Glass microscope slides from the 23 PES were examined for airborne ambrosia beetle frass and wood particles by microscopy. DNA was extracted from the slides and tested by qPCR (quantitative polymerase chain reaction) for C. lukuohia and C. huliohia. We also investigated the correlation of beetle gallery counts with tree height and tested the efficacy of Bifen I/T insecticide (active ingredient: bifenthrin 7.9%) for preventing beetle attacks on the cut surface of ‘ōhi‘a bolts (tree stem sections). Beetle trapping data revealed that the area supports a diverse community of wood-boring beetles, some of which likely attack ‘ōhi‘a and may facilitate the spread of ROD. The number of beetle galleries on felled ‘ōhi‘a trees decreased linearly as tree height increased. We also observed significantly fewer beetle attacks on Bifen I/T treated ‘ōhi‘a bolts than non-treated bolts, but gallery formation nearly ceased in both treated and control bolts by week three. Ceratocystis lukuohia DNA was detected twenty-six times and C. huliohia was detected five times in the PES throughout this study. DNA detections were correlated to frass and wood counts, and the number of felled trees were correlated to wood particle counts but not frass counts. Both the timing and distribution of detections across the sampling grid indicate that tree felling may have reduced airborne detections of Ceratocystis DNA soon after tree felling was completed. A subsequent increase in detections after tree felling ceased may indicate that incomplete removal of infected trees and the appearance of new infections in previously asymptomatic trees could have allowed airborne detections of potentially infectious fungal propagules to once again increase.

Hawaii↗

USGS2020

Successful restoration of Metrosideros polymorpha (ʻōhiʻa) is possible in forest sites with active Rapid ‘Ōhiʻa Death infections

Rapid ʻŌhiʻa Death (ROD), caused by the fungal pathogen Ceratocystis , is killing large numbers of ʻōhiʻa trees ( Metrosideros polymorpha ) in Hawaiʻi. ʻŌhiʻa are a dominant tree in Hawaiian forests, have a range that goes from arid to wet forest climates, and are important for endangered species habitat and ecosystem function. To test whether actively planting ʻōhiʻa seedlings is a viable restoration strategy in areas with high ROD mortality, we planted ʻōhiʻa in a ROD‐affected forest and crossed this with weeding and fencing treatments to compare ROD mortality to other stressors. We also tested for viable Ceratocystis spores in soils around planting areas. We found that seedlings were more likely to die in unweeded and unfenced treatments than controls. Although viable Ceratocystis spores were found in soil, none of the 41 dead seedlings tested positive for Ceratocystis . This indicates that competition from exotic plants and exotic feral ungulate damage are more likely to kill seedlings than ROD within the first year after planting.

Hawaii↗

USGS2020

Ambrosia beetle (Coleoptera: Curculionidae) communities and frass production in ʻŌhiʻa (Myrtales: Myrtaceae) infected with Ceratocystis (Microascales: Ceratocystidaceae) fungi responsible for Rapid ʻŌhiʻa Death

Rapid ʻŌhiʻa Death (ROD) is a deadly disease that is threatening the native Hawaiian keystone tree species, ʻōhiʻa lehua ( Metrosideros polymorpha Gaudich). Ambrosia beetles (Curculionidae: Scolytinae) and their frass are hypothesized to play a major role in the spread of ROD, although their ecological niches and frass production within trees and across the landscape are not well understood. We characterized the beetle communities and associated frass production from bolts (tree stem sections) representative of entire individual ʻōhiʻa trees from multiple locations across Hawaiʻi Island by rearing beetles and testing their frass for viable ROD-causing fungi. Additionally, we estimated frass production for three beetle species by weighing their frass over time. We found that Xyleborinus saxesenii (Ratzburg), Xyleborus affinis Eichhoff, Xyleborus ferrugineus (Fabricius), Xyleborus perforans (Wollaston), and Xyleborus simillimus Perkins were commonly found on ROD-infected ʻōhiʻa and each produced frass containing viable Ceratocystis propagules. The Hawaiʻi Island endemic beetle and the only native ambrosia beetle associated with ʻōhiʻa, X. simillimus , was limited to high elevations and appeared to utilize similar tree heights or niche dimensions as the invasive X. ferrugineus . Viable Ceratocystis propagules expelled in frass were found throughout entire tree bole sections as high as 13 m. Additionally, we found that X. ferrugineus produced over 4× more frass than X. simillimus . Our results indicate the ambrosia beetle community and their frass play an important role in the ROD pathosystem. This information may help with the development and implementation of management strategies to control the spread of the disease.

Hawaii↗

USGS2020

Decontamination of Ceratocystis pathogens responsible for rapid ʻŌhiʻa Death

Rapid ʻōhiʻa death (ROD) is caused by two recently described species of Ceratocystis , C. lukuohia and C . huliohia . These fungi are decimating ʻōhiʻa lehua ( Metrosideros polymorpha ), the keystone native tree species of Hawaiʻi. Viable Ceratocystis propagules can persist in ambrosia beetle frass (Coleoptera: Scolytinae), and movement of the frass may play a key role in the spread of the disease. In order to prevent the spread of ROD, we developed effective and practical surface (e.g., tools and shoes) decontamination methods to be used by researchers, managers, and the public alike. We first tested different household and laboratory disinfectants on the Ceratocystis fungi in culture, and then we applied the effective culture disinfectants to contaminated ambrosia beetle frass. Laboratory-grade ethanol (70, 80, and 95%), Clorox bleach (10%, 0.825% active ingredient [a.i.]), and isopropanol (70 and 91%), were all equally effective at decontaminating cultured C. lukuohia and C. huliohia. Although all concentrations of isopropanol (50, 70, and 90%) and ethanol (50, 70, and 90%) were effective disinfectants of Ceratocystis -contaminated frass, treatments of frass with up to 20% Clorox bleach (1.2% a.i.) were not completely adequate at killing the fungus. These data reveal that bleach is not a sufficient ROD disinfectant when frass is present, and isopropanol or ethanol are the more reliable options.

Hawaii↗

USGS2019

Economical environmental sampler designs for detecting airborne spread of fungi responsible for Rapid `Ōhi`a Death

We designed two new samplers for monitoring airborne particulates that rely on either natural wind currents (Passive Environmental Sampler) or a battery-operated fan (Active Environmental Sampler). Both samplers are significantly less expensive than commercial devices such as Rotorod® and Burkard Samplers that are used in the agricultural and health science industries. They are economical enough to be deployed in large numbers across broad landscapes. We evaluated their use for detecting airborne spread of ambrosia beetle frass that may contain infective spores of the fungi (Ceratocystis lukuohia and C. huliohia) that are responsible for Rapid `Ōhi`a Death (ROD), a newly documented pathosystem on Hawai`i Island. We compared performance of the new samplers to Rotorod® Model 20 Samplers by releasing synthetic polyethylene spheres (12–160 µm in diameter) and also Xyleborus spp. frass known to contain C. lukuohia and C. huliohia propagules under controlled laboratory and field conditions. Overall, the Active Environmental Sampler proved to be 3–4 times more effective in capturing polyethylene spheres and 2–3 times more effective in capturing frass than either the Passive or Rotorod® Samplers. Significant differences between the Passive and Rotorod® Samplers were not detected. For the frass release experiment, C. lukuohia DNA was detected once by qPCR in an Active Environmental Sampler and C. huliohia DNA was detected during two different trials, once with an Active Environmental Sampler and once with a Passive Environmental Sampler. No detections were made with Rotorod® Samplers. Both Active and Passive Samplers were used in the field for detection of airborne dispersal of C. lukuohia and C. huliohia at Orchidlands Estates in the Puna District of Hawai`i Island. We found that airborne dispersal of potentially infective beetle frass was uncommon over short distances with qPCR detections in up to 10% of weekly sampler collections.

Hawai`i Cooperative Studies Unit Technical Report↗

USGS2017

A rapid diagnostic test and mobile "lab in a suitcase" platform for detecting Ceratocystis spp. responsible for Rapid ‘Ōhi‘a Death

We describe a field compatible molecular diagnostic test for two new species of Ceratocystis that infect `ōhi`a (Metrosideros polymorpha) and cause the disease commonly known as Rapid `Ōhi`a Death. The diagnostic is based on amplification of a DNA locus within the internal transcribed spacer region that separates fungal 5.8S ribosomal genes. The assay uses forward and reverse primers, recombinase polymerase, and a fluorescent probe that allows isothermal (40oC) amplification and simultaneous quantification of a 115 base pair product with a battery operated fluorometer. DNA extractions are field compatible and can be done by heating wood drill shavings to 100oC in Instagene® solution containing Chelex® resin to bind potential amplification inhibitors. The initial heat treatment is followed by a short bead beating step with steel ball bearings and zirconium beads to release DNA. DNA is subsequently purified with a magnetic bead based extraction method that does not require silica columns or centrifugation. The assay is designed around a portable “lab-in-a-suitcase” platform that includes a portable fluorometer, miniature centrifuge, and heat block that operate off either 120V AC power sources or a 12 volt battery with a portable inverter, a magnetic rack designed for 1.5 ml tubes and magnetic bead DNA purification, pipettes and consumable reagents and tubes. The entire assay from DNA extraction to results can be performed in less than 90 minutes on up to six independent samples plus a positive and negative control. Sensitivity based on suspensions of Ceratocystis endoconidia (spores) that were added to wood shavings and processed under field conditions by Instagene® magnetic bead DNA extraction was up to 163 spores/mg wood for Species A and 55 spores/mg wood for Species B in 95% of replicates as determined by probit analysis. Sensitivity increased 5–10 fold to 19 spores/mg wood for Species A and 9 spores/mg wood for Species B when extractions were performed with a commercial, silica column based DNA purification kit. The test did not cross react with other common fungi that have been isolated from `ōhi`a.

Technical Report↗