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Stephen W Fraedrich - One of the best experts on this subject based on the ideXlab platform.

  • first report of laurel wilt disease caused by raffaelea lauricola on spicebush in louisiana
    Plant Disease, 2019
    Co-Authors: Rabiu Olatinwo, Wood Johnson, J. Hwang, Stephen W Fraedrich
    Abstract:

    In the past two decades, laurel wilt disease has significantly affected members of the Lauraceae in the southeast United States, causing widespread mortality of native redbay (Persea borbonia (L.) Spreng), and incidence of infections in avocado (Persea americana Mill.), Sassafras (Sassafras albidum L.) and swamp bay (Persea palustris [Raf.] Sarg.) (Fraedrich et al., 2008, 2015, Olatinwo, et al. 2019). Laurel wilt is a vascular disease caused by Raffaelea lauricola (T.C. Harr., Fraedrich & Aghayeva), a fungus vectored by a non-native ambrosia beetle Xyleborus glabratus Eichhoff (Fraedrich et al. 2008). In August 2020, we investigated the mortality of a spicebush shrub (Lindera benzoin L.) (3.8 cm diameter at root collar, two m height) located ca. 17 mi northeast of Colfax, Grant Parish, Louisiana (31.750263° N, -92.643694° W). Evaluation of the dead shrub revealed brown, persistent foliage, and black vascular discoloration of the sapwood, typical symptoms of laurel wilt (Fig. S1). Although, beetle holes were observed on the sapwood, no beetle was found in galleries at the time. In the laboratory, a fungus consistently isolated from surface-sterilized sapwood tissues plated on potato dextrose agar (PDA) was identified as R. lauricola based on the morphological characteristics of the isolate (i.e., mucoid growth, conidiophores, and oblong/ovoid shape conidia [Harrington et al. 2008]). The fungal isolate was denoted as SB1. The identity of the fungus was confirmed by positive PCR amplification of the large subunit ribosomal RNA gene region using species-specific primers; rab-lsu-rl_F: CCCTCGCGGCGTATTATAG and rab-lsu-rl_R: GCGGGGCTCCTACTCAAA (Olatinwo, unpublished). The sequence of the isolate SB1 (GenBank Accession no. MW207371) showed 100% homology to the R. lauricola strain CBS 127349 sequence (GenBank Accession no. MH877933). The pathogenicity of SB1 on spicebush was evaluated on four healthy shrubs (average: 1 m height and 40 mm in diameter) at the location from which the original detection was made. Stems of two spicebush shrubs were inoculated with SB1 agar plugs from a 14-day old culture on PDA, while plain PDA plugs were used on the remaining two shrubs as non-inoculated controls. Agar plugs were placed in 5 mm (0.2 in) diameter hole punched on the bark with cork-borer as described by Mayfield et al (2008). After six weeks, the R. lauricola inoculated shrubs were wilted with noticeable blackened tissue discoloration in the sapwood, while the control trees remained healthy (Fig. S2). Raffaelea lauricola was re-isolated from tissue of the two inoculated, symptomatic shrubs, but not from the control trees. The sequence of the re-isolated R. lauricola isolate, denoted as SB3 (GenBank Accession no. MW207372), showed 100% homology to the R. lauricola strain CBS 127349 and isolate SB1. This first documentation of laurel wilt on spicebush in Louisiana is significant because, spicebush berries, leaves, and twigs are food sources for forest animals, birds, and insects including whitetail deer and spicebush swallowtail (Papilio troilus L.). Since its first report on Sassafras in 2014 (Fraedrich et al. 2015), laurel wilt has spread across Louisiana on Sassafras and swamp bay (Olatinwo et al. 2019) and has been confirmed in14 parishes. This report shows the relentless nature of the disease, as the pathogen moves from one vulnerable host to the next, expanding into new locations and threatening forest ecosystems across the southern United States.

  • first report of laurel wilt caused by raffaelea lauricola on Sassafras Sassafras albidum in alabama
    Plant Disease, 2013
    Co-Authors: C A Bates, Thomas C. Harrington, Stephen W Fraedrich, Roger D Menard, R S Cameron, G S Best
    Abstract:

    Laurel wilt, caused by Raffaelea lauricola, a fungal symbiont of the redbay ambrosia beetle, Xyleborus glabratus, is responsible for extensive mortality of native redbays (Persea borbonia and P. palustris) in the coastal plains of the southeastern United States (1). The wilt also affects the more widespread Sassafras, Sassafras albidum, particularly in areas where diseased redbays are common and populations of X. glabratus are high. Because Sassafras stems were thought to lack chemicals that are attractive to the beetle, and Sassafras tends to be widely scattered in forests, it was believed that the advance of the laurel wilt epidemic front might slow once it reached the edge of the natural range of redbay, which is restricted to the coastal plains of the Gulf and Atlantic Coasts (2). In July and August of 2011, wilt-like symptoms (i.e., wilted and dead leaves, and streaks of black discoloration in the xylem) were observed on 1 to 10 Sassafras trees (15 to 23 cm diameter; 6 to 9 m height) at each of three locations, which were approximately 6 km from one another in Marengo Co., Alabama. Samples of the discolored wood from five trees were plated on malt agar amended with cycloheximide and streptomycin (CSMA), and a fungus morphologically identical to R. lauricola was isolated from each tree (1). For confirmation, a portion of the large subunit (28S) of the rDNA region of three of the isolates was sequenced (3); in each case, the sequence matched exactly that of other isolates of R. lauricola (EU123077) from the United States. Symptomatic trees were found at all three sites when revisited in April 2012, and approximately 20 Sassafras trees in various stages of wilt were observed at one location, where only one diseased tree had been noted in 2011. Bolts were cut from the main stem of a symptomatic tree, and eggs, larvae, and adults of X. glabratus were commonly found in tunnels, and R. lauricola was isolated from the discolored xylem. Three container-grown Sassafras saplings (mean height 193 cm, mean diameter 2.1 cm at groundline) were inoculated as previously described (1) with conidia (~600,000) from an isolate of R. lauricola. Three additional Sassafras saplings were inoculated with sterile, deionized water, and all plants were placed in a growth chamber at 25°C with a 15-h photoperiod. Inoculated plants began to exhibit wilt symptoms within 14 days, and at 30 days all inoculated plants were dead and xylem discoloration was observed. Control plants appeared healthy and did not exhibit xylem discoloration. Pieces of sapwood from 15 cm above the inoculation points were plated on CSMA, and R. lauricola was recovered from all wilted plants but not from control plants. This is the first record of laurel wilt in Alabama and is significant because the disease appears to be spreading on Sassafras in an area where redbays have not been recorded (see http://www.floraofalabama.org ). The nearest previously documented case of laurel wilt is on redbay and Sassafras in Jackson Co., Mississippi (4), approximately 160 km to the south. The exact source of the introduction of X. glabratus and R. lauricola into Marengo Co. is not known. The vector may have been transported into the area with storms, moved with infested firewood, or shipped with infested timber by companies that supply mills in the area. References: (1) S. Fraedrich et al. Plant Dis. 92:215, 2008. (2) J. Hanula et al. Econ. Ent. 101:1276, 2008. (3) T. Harrington et al. Mycotaxon 111:337, 2010. (4) J. Riggins et al. Plant Dis. 95:1479, 2011.

  • first report of laurel wilt caused by raffaelea lauricola on Sassafras Sassafras albidum in alabama
    Plant Disease, 2013
    Co-Authors: Rabiu Olatinwo, C Barton, Wood Johnson, Stephen W Fraedrich, J. Hwang
    Abstract:

    Laurel wilt, caused by Raffaelea lauricola, a fungal symbiont of the redbay ambrosia beetle, Xyleborus glabratus, is responsible for extensive mortality of native redbays (Persea borbonia and P. palustris) in the coastal plains of the southeastern United States (1). The wilt also affects the more widespread Sassafras, Sassafras albidum, particularly in areas where diseased redbays are common and populations of X. glabratus are high. Because Sassafras stems were thought to lack chemicals that are attractive to the beetle, and Sassafras tends to be widely scattered in forests, it was believed that the advance of the laurel wilt epidemic front might slow once it reached the edge of the natural range of redbay, which is restricted to the coastal plains of the Gulf and Atlantic Coasts (2). In July and August of 2011, wilt-like symptoms (i.e., wilted and dead leaves, and streaks of black discoloration in the xylem) were observed on 1 to 10 Sassafras trees (15 to 23 cm diameter; 6 to 9 m height) at each of three...

  • first report of laurel wilt caused by raffaelea lauricola on Sassafras in mississippi
    Plant Disease, 2011
    Co-Authors: John J. Riggins, Stephen W Fraedrich, Thomas C. Harrington
    Abstract:

    Laurel wilt is caused by the fungus Raffaelea lauricola T.C. Harrin., Aghayeva & Fraedrich and is lethal to redbay (Persea borbonia (L.) Spreng.), Sassafras (Sassafras albidum (Nutt.) Nees), and other species in the Lauraceae (1). The fungus is carried by the redbay ambrosia beetle (Xyleborus glabratus Eichh.), which is native to Asia. After being discovered in Georgia in 2002 (1), X. glabratus and R. lauricola have spread rapidly, causing extensive redbay mortality in South Carolina, Georgia, Florida, and Mississippi (1,4). The disease has also been confirmed on Sassafras in Florida, South Carolina (1), and Georgia. Questions remain as to whether laurel wilt will continue to spread on Sassafras, which often occurs as scattered trees in the eastern United States. In June 2010, a homeowner reported that a Sassafras tree north of Van Cleave, MS (30.668°N, 88.686°W) had begun wilting in late May. This landscape tree had three 10-m high stems (~20 cm in diameter at breast height). Dark staining in the xylem was observed around the entire circumference of all three stems and nearly all leaves were bronze colored and wilted. No ambrosia beetle tunnels were observed in the stems. No other symptomatic Lauraceae were encountered in the wooded area within 300 m. The nearest known location with laurel wilt on redbay was ~15 km away (4). A Lindgren funnel trap baited with manuka oil (2) was placed at the site in June and monitored biweekly until November, but no X. glabratus adults were captured. Chips from discolored xylem of the Sassafras were surface sterilized, plated on cycloheximide-streptomycin malt agar, and R. lauricola was readily isolated (1). Identity of the fungus (isolate C2792 in collection of T. Harrington) was confirmed by using partial sequences of the 28S rDNA (3). The Sassafras sequence was identical to that of all known sequences of R. lauricola in the United States, including GenBank No. EU123076 (the holotype isolate from redbay). To confirm pathogenicity, isolate C2792 was grown on malt extract agar and three redbay (average: 141 cm high and 12 mm in diameter at soil interface) and three Sassafras (average: 170 cm high and 17 mm in diameter at soil interface) potted plants were wound inoculated with 0.2 ml of a spore suspension (4.9 × 106 conidia/ml) (1). Three control plants of each species were inoculated with sterile deionized water. After 8 weeks in a growth chamber at 26°C, all inoculated redbay and Sassafras plants exhibited xylem discoloration above and below the inoculation point, two of the redbay and two of the Sassafras had died, and the other plant of each species exhibited partial wilt (the main terminal or one or more branches). All control plants were asymptomatic. R. lauricola was reisolated from all inoculated symptomatic plants but not from controls. To our knowledge, this is the first report of laurel wilt on Sassafras in Mississippi. Both redbay (4) and Sassafras appear to be highly susceptible to the disease as it moves westward. Sassafras is less attractive than redbay to X. glabratus and it was thought that this might contribute to slowing the spread of laurel wilt once outside the range of redbay (2). Nonetheless, our observations confirm that Sassafras can be infected where laurel wilt on redbay is not in the immediate vicinity. References: (1) S. W. Fraedrich et al. Plant Dis. 92:215, 2008. (2) J. L. Hanula et al. J. Econ. Entomol. 101:1276, 2008. (3) T. C. Harrington et al. Mycotaxon 111:337, 2010. (4) J. J. Riggins et al. Plant Dis. 94:634, 2010.

  • first report of laurel wilt disease caused by raffaelea lauricola on Sassafras in florida and south carolina
    Plant Disease, 2009
    Co-Authors: Jason A Smith, Stephen W Fraedrich, Albert E Mayfield, T J Dreaden, A Boone, C Bates
    Abstract:

    Laurel wilt disease, caused by Raffaelea lauricola (T.C. Harr., Fraedrich & Aghayeva sp. nov.), which is a fungal symbiont of the nonnative redbay ambrosia beetle (Xyleborus glabratus Eichhoff), has caused widespread mortality of native redbay (Persea borbonia (L.) Spreng) in Georgia, South Carolina, and Florida since 2002. The disease has been noted on other species in the Lauraceae including Sassafras in Georgia (1), and more recently, on avocado and camphor in Florida (4). Since 2005, wilted shoots, branch dieback, and tree death have been observed in Sassafras trees (Sassafras albidum (L.)) in Liberty, McIntosh, Chatham, Effingham, Bulloch, Evans, and Screven counties in Georgia; Bamberg, Beaufort, Charleston, Colleton, Hampton, and Orangeburg counties in South Carolina; and Putnam County in Florida. Symptomatic Sassafras trees ranged from 1 to 12 m high and 2.5 to 25 cm in diameter at breast height. In contrast to red bay trees that retain wilted foliage, symptomatic Sassafras defoliate rapidly as trees wilt and die. Multiple symptomatic ramets originating from a common root system have been observed. Removal of bark from stem and root sections from wilted trees revealed black-to-brownish staining in the sapwood, characteristic of laurel wilt. Wood chips from symptomatic areas of branches and roots were surface sterilized and plated on cycloheximide-streptomycin malt agar as previously described (1) and R. lauricola was routinely isolated. Small subunit (18S) sequences from rDNA were amplified by PCR and sequenced using primers NS1 and NS4 (3) for isolates from Sassafras from Florida and South Carolina. BLASTn searches revealed homology to Raffaelea sp. C2203 (GenBank Accession No. EU123076, 100% similarity) described by Fraedrich et al. (1) from redbay and later named R. lauricola (2). The small subunit rDNA sequences for these isolates have been deposited into GenBank ( http://www.ncbi.nlm.nih.gov/Genbank/index.html ) and assigned Accession Nos. EU980448 (Florida) and GQ329704 (South Carolina). Koch's postulates have been completed with R. lauricola on this host previously (1). Laurel wilt on Sassafras often was geographically isolated from other symptomatic hosts in Georgia and South Carolina and appears to occur on this host independently of proximity to redbay. Further studies to determine the epidemiology of laurel wilt on Sassafras, potential resistance, and impact on Sassafras life history and distribution are needed. Given the clonal nature of Sassafras, the disease would appear to have the potential to move through roots of trees once established in a stand. References: (1) S. W Fraedrich et al. Plant Dis. 92:215, 2008. (2) T. C. Harrington et al. Mycotaxon 104:399, 2008. (3) M. A. Innis et al. PCR Protocols, A Guide to Methods and Applications. Academic Press, San Diego, CA, 1990. (4) J. A. Smith et al. Plant Dis. 93:198, 2009.

John J. Riggins - One of the best experts on this subject based on the ideXlab platform.

  • cold tolerance and invasive potential of the redbay ambrosia beetle xyleborus glabratus in the eastern united states
    Biological Invasions, 2018
    Co-Authors: John P Formby, John C Rodgers, Frank H Koch, Natraj Krishnan, Donald A Duerr, John J. Riggins
    Abstract:

    Native Lauraceae (e.g. Sassafras, redbay) in the southeastern USA are being severely impacted by laurel wilt disease, which is caused by the pathogen Raffaelea lauricola T. C. Harr., Fraedrich and Aghayeva, and its symbiotic vector, the redbay ambrosia beetle (Xyleborus glabratus Eichhoff). Cold temperatures are currently the only viable limitation to the establishment of X. glabratus in northern populations of Sassafras. The observed lower lethal temperature of X. glabratus (− 10.0 °C) is warmer than its supercooling point (− 22.0 °C), indicating the beetle is a freeze intolerant and chill susceptible species. Empirically derived X. glabratus lower lethal temperature thresholds were combined with host distribution and microhabitat-corrected climate data to produce species distribution models for X. glabratus in the eastern USA. Macroclimate data (30-year mean annual minimum temperature) were corrected (− 1.2 °C) to account for thermal buffering afforded to X. glabratus while living inside Sassafras trees. Only 0.1% of the current US Sassafras spatial extent experiences sufficiently harsh winters (locales where mean annual minimum winter temperatures ≤ − 6.2 °C for ≥ 12 h) to exclude X. glabratus establishment in our species distribution model. Minimum winter temperatures will likely cause some X. glabratus mortality in ~ 52% of the current spatial extent of Sassafras, although current data do not allow a quantification of X. glabratus mortality in this zone. Conversely, ~ 48% of the current spatial extent of Sassafras is unlikely to experience sufficiently cold winter temperatures to cause any significant impediment to X. glabratus spread or establishment. A modest climate change scenario (RCP4.5) of + 1.4 °C would result in 91% of the current spatial extent of Sassafras in the eastern USA occurring where winter minimum temperatures are unlikely to cause any mortality to X. glabratus.

  • First Records of Xyleborus glabratus (Coleoptera: Curculionidae) in Alabama and in Harrison County, Mississippi
    Florida Entomologist, 2012
    Co-Authors: John P Formby, Terence L. Schiefer, John J. Riggins
    Abstract:

    family Lauraceae (Fraedrich et al. 2008). Known hosts include, but are not limited to redbay (Per sea borbonia (L.) Spreng.), avocado (Persea ameri cana Mill.), Sassafras (Sassafras albidum (Nutt.) Nees), camphor (Cinnamomum camphora (L.) J. Presl), and swampbay (Persea palustris (Raf.) Sarg.) (Fraedrich et al. 2008). While the direct feeding damage caused by X. glabratus may not be significant, the beetle carries various species of fungal symbionts within mycangia at the base of its mandibles. As the female beetle bores into

  • first report of laurel wilt caused by raffaelea lauricola on Sassafras in mississippi
    Plant Disease, 2011
    Co-Authors: John J. Riggins, Stephen W Fraedrich, Thomas C. Harrington
    Abstract:

    Laurel wilt is caused by the fungus Raffaelea lauricola T.C. Harrin., Aghayeva & Fraedrich and is lethal to redbay (Persea borbonia (L.) Spreng.), Sassafras (Sassafras albidum (Nutt.) Nees), and other species in the Lauraceae (1). The fungus is carried by the redbay ambrosia beetle (Xyleborus glabratus Eichh.), which is native to Asia. After being discovered in Georgia in 2002 (1), X. glabratus and R. lauricola have spread rapidly, causing extensive redbay mortality in South Carolina, Georgia, Florida, and Mississippi (1,4). The disease has also been confirmed on Sassafras in Florida, South Carolina (1), and Georgia. Questions remain as to whether laurel wilt will continue to spread on Sassafras, which often occurs as scattered trees in the eastern United States. In June 2010, a homeowner reported that a Sassafras tree north of Van Cleave, MS (30.668°N, 88.686°W) had begun wilting in late May. This landscape tree had three 10-m high stems (~20 cm in diameter at breast height). Dark staining in the xylem was observed around the entire circumference of all three stems and nearly all leaves were bronze colored and wilted. No ambrosia beetle tunnels were observed in the stems. No other symptomatic Lauraceae were encountered in the wooded area within 300 m. The nearest known location with laurel wilt on redbay was ~15 km away (4). A Lindgren funnel trap baited with manuka oil (2) was placed at the site in June and monitored biweekly until November, but no X. glabratus adults were captured. Chips from discolored xylem of the Sassafras were surface sterilized, plated on cycloheximide-streptomycin malt agar, and R. lauricola was readily isolated (1). Identity of the fungus (isolate C2792 in collection of T. Harrington) was confirmed by using partial sequences of the 28S rDNA (3). The Sassafras sequence was identical to that of all known sequences of R. lauricola in the United States, including GenBank No. EU123076 (the holotype isolate from redbay). To confirm pathogenicity, isolate C2792 was grown on malt extract agar and three redbay (average: 141 cm high and 12 mm in diameter at soil interface) and three Sassafras (average: 170 cm high and 17 mm in diameter at soil interface) potted plants were wound inoculated with 0.2 ml of a spore suspension (4.9 × 106 conidia/ml) (1). Three control plants of each species were inoculated with sterile deionized water. After 8 weeks in a growth chamber at 26°C, all inoculated redbay and Sassafras plants exhibited xylem discoloration above and below the inoculation point, two of the redbay and two of the Sassafras had died, and the other plant of each species exhibited partial wilt (the main terminal or one or more branches). All control plants were asymptomatic. R. lauricola was reisolated from all inoculated symptomatic plants but not from controls. To our knowledge, this is the first report of laurel wilt on Sassafras in Mississippi. Both redbay (4) and Sassafras appear to be highly susceptible to the disease as it moves westward. Sassafras is less attractive than redbay to X. glabratus and it was thought that this might contribute to slowing the spread of laurel wilt once outside the range of redbay (2). Nonetheless, our observations confirm that Sassafras can be infected where laurel wilt on redbay is not in the immediate vicinity. References: (1) S. W. Fraedrich et al. Plant Dis. 92:215, 2008. (2) J. L. Hanula et al. J. Econ. Entomol. 101:1276, 2008. (3) T. C. Harrington et al. Mycotaxon 111:337, 2010. (4) J. J. Riggins et al. Plant Dis. 94:634, 2010.

Thomas C. Harrington - One of the best experts on this subject based on the ideXlab platform.

  • first report of xyleborus glabratus coleoptera curculionidae scolytinae and laurel wilt in louisiana usa the disease continues westward on Sassafras
    Florida Entomologist, 2015
    Co-Authors: Wood C Johnson, Rabiu Olatinwo, Thomas C. Harrington, Roger D Menard, Susan G Best
    Abstract:

    Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae: Scolytinae) and Sassafras trees that died from laurel wilt were discovered in a 3-parish area of northern Louisiana, USA, in Sep 2014. Redbay, a species that has been severely affected by the disease in the coastal plains forests of the southeastern USA, is not found in this area of northern Louisiana, suggesting that Sassafras is attractive to X. glabratus and an adequate reproductive host for the beetle. This is the first report of X. glabratus and laurel wilt in Louisiana and the first report of the beetle and disease west of the Mississippi River. Sumario En septiembre del 2014, Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae: Scolytinae) y arboles de sasafras que murieron a causa de la marchitez del laurel fueron descubiertos en un area de 3 municipios del norte de Louisiana, EE.UU. El aguacatillo ( Persea borbonia ), una especie que se ha visto gravemente afectada por la enfermedad en los bosques de la llanura costero del sudeste de EE.UU., no se encuentra en esta zona del norte de Louisiana, lo que sugiere que el sasafras es atractivo para X. glabratus y un hospedero reproductivo adecuado para el escarabajo. Este es el primer informe de X. glabratus y la marchitez del laurel en Louisiana y el primer informe del escarabajo y la enfermedad al oeste del rio Mississippi. View this article in BioOne

  • first report of laurel wilt caused by raffaelea lauricola on Sassafras Sassafras albidum in alabama
    Plant Disease, 2013
    Co-Authors: C A Bates, Thomas C. Harrington, Stephen W Fraedrich, Roger D Menard, R S Cameron, G S Best
    Abstract:

    Laurel wilt, caused by Raffaelea lauricola, a fungal symbiont of the redbay ambrosia beetle, Xyleborus glabratus, is responsible for extensive mortality of native redbays (Persea borbonia and P. palustris) in the coastal plains of the southeastern United States (1). The wilt also affects the more widespread Sassafras, Sassafras albidum, particularly in areas where diseased redbays are common and populations of X. glabratus are high. Because Sassafras stems were thought to lack chemicals that are attractive to the beetle, and Sassafras tends to be widely scattered in forests, it was believed that the advance of the laurel wilt epidemic front might slow once it reached the edge of the natural range of redbay, which is restricted to the coastal plains of the Gulf and Atlantic Coasts (2). In July and August of 2011, wilt-like symptoms (i.e., wilted and dead leaves, and streaks of black discoloration in the xylem) were observed on 1 to 10 Sassafras trees (15 to 23 cm diameter; 6 to 9 m height) at each of three locations, which were approximately 6 km from one another in Marengo Co., Alabama. Samples of the discolored wood from five trees were plated on malt agar amended with cycloheximide and streptomycin (CSMA), and a fungus morphologically identical to R. lauricola was isolated from each tree (1). For confirmation, a portion of the large subunit (28S) of the rDNA region of three of the isolates was sequenced (3); in each case, the sequence matched exactly that of other isolates of R. lauricola (EU123077) from the United States. Symptomatic trees were found at all three sites when revisited in April 2012, and approximately 20 Sassafras trees in various stages of wilt were observed at one location, where only one diseased tree had been noted in 2011. Bolts were cut from the main stem of a symptomatic tree, and eggs, larvae, and adults of X. glabratus were commonly found in tunnels, and R. lauricola was isolated from the discolored xylem. Three container-grown Sassafras saplings (mean height 193 cm, mean diameter 2.1 cm at groundline) were inoculated as previously described (1) with conidia (~600,000) from an isolate of R. lauricola. Three additional Sassafras saplings were inoculated with sterile, deionized water, and all plants were placed in a growth chamber at 25°C with a 15-h photoperiod. Inoculated plants began to exhibit wilt symptoms within 14 days, and at 30 days all inoculated plants were dead and xylem discoloration was observed. Control plants appeared healthy and did not exhibit xylem discoloration. Pieces of sapwood from 15 cm above the inoculation points were plated on CSMA, and R. lauricola was recovered from all wilted plants but not from control plants. This is the first record of laurel wilt in Alabama and is significant because the disease appears to be spreading on Sassafras in an area where redbays have not been recorded (see http://www.floraofalabama.org ). The nearest previously documented case of laurel wilt is on redbay and Sassafras in Jackson Co., Mississippi (4), approximately 160 km to the south. The exact source of the introduction of X. glabratus and R. lauricola into Marengo Co. is not known. The vector may have been transported into the area with storms, moved with infested firewood, or shipped with infested timber by companies that supply mills in the area. References: (1) S. Fraedrich et al. Plant Dis. 92:215, 2008. (2) J. Hanula et al. Econ. Ent. 101:1276, 2008. (3) T. Harrington et al. Mycotaxon 111:337, 2010. (4) J. Riggins et al. Plant Dis. 95:1479, 2011.

  • first report of laurel wilt caused by raffaelea lauricola on Sassafras in mississippi
    Plant Disease, 2011
    Co-Authors: John J. Riggins, Stephen W Fraedrich, Thomas C. Harrington
    Abstract:

    Laurel wilt is caused by the fungus Raffaelea lauricola T.C. Harrin., Aghayeva & Fraedrich and is lethal to redbay (Persea borbonia (L.) Spreng.), Sassafras (Sassafras albidum (Nutt.) Nees), and other species in the Lauraceae (1). The fungus is carried by the redbay ambrosia beetle (Xyleborus glabratus Eichh.), which is native to Asia. After being discovered in Georgia in 2002 (1), X. glabratus and R. lauricola have spread rapidly, causing extensive redbay mortality in South Carolina, Georgia, Florida, and Mississippi (1,4). The disease has also been confirmed on Sassafras in Florida, South Carolina (1), and Georgia. Questions remain as to whether laurel wilt will continue to spread on Sassafras, which often occurs as scattered trees in the eastern United States. In June 2010, a homeowner reported that a Sassafras tree north of Van Cleave, MS (30.668°N, 88.686°W) had begun wilting in late May. This landscape tree had three 10-m high stems (~20 cm in diameter at breast height). Dark staining in the xylem was observed around the entire circumference of all three stems and nearly all leaves were bronze colored and wilted. No ambrosia beetle tunnels were observed in the stems. No other symptomatic Lauraceae were encountered in the wooded area within 300 m. The nearest known location with laurel wilt on redbay was ~15 km away (4). A Lindgren funnel trap baited with manuka oil (2) was placed at the site in June and monitored biweekly until November, but no X. glabratus adults were captured. Chips from discolored xylem of the Sassafras were surface sterilized, plated on cycloheximide-streptomycin malt agar, and R. lauricola was readily isolated (1). Identity of the fungus (isolate C2792 in collection of T. Harrington) was confirmed by using partial sequences of the 28S rDNA (3). The Sassafras sequence was identical to that of all known sequences of R. lauricola in the United States, including GenBank No. EU123076 (the holotype isolate from redbay). To confirm pathogenicity, isolate C2792 was grown on malt extract agar and three redbay (average: 141 cm high and 12 mm in diameter at soil interface) and three Sassafras (average: 170 cm high and 17 mm in diameter at soil interface) potted plants were wound inoculated with 0.2 ml of a spore suspension (4.9 × 106 conidia/ml) (1). Three control plants of each species were inoculated with sterile deionized water. After 8 weeks in a growth chamber at 26°C, all inoculated redbay and Sassafras plants exhibited xylem discoloration above and below the inoculation point, two of the redbay and two of the Sassafras had died, and the other plant of each species exhibited partial wilt (the main terminal or one or more branches). All control plants were asymptomatic. R. lauricola was reisolated from all inoculated symptomatic plants but not from controls. To our knowledge, this is the first report of laurel wilt on Sassafras in Mississippi. Both redbay (4) and Sassafras appear to be highly susceptible to the disease as it moves westward. Sassafras is less attractive than redbay to X. glabratus and it was thought that this might contribute to slowing the spread of laurel wilt once outside the range of redbay (2). Nonetheless, our observations confirm that Sassafras can be infected where laurel wilt on redbay is not in the immediate vicinity. References: (1) S. W. Fraedrich et al. Plant Dis. 92:215, 2008. (2) J. L. Hanula et al. J. Econ. Entomol. 101:1276, 2008. (3) T. C. Harrington et al. Mycotaxon 111:337, 2010. (4) J. J. Riggins et al. Plant Dis. 94:634, 2010.

  • a fungal symbiont of the redbay ambrosia beetle causes a lethal wilt in redbay and other lauraceae in the southeastern united states
    Plant Disease, 2008
    Co-Authors: Stephen W Fraedrich, Thomas C. Harrington, Robert J Rabaglia, James L. Hanula, Michael D Ulyshen, J M Eickwort, Daniel R Miller
    Abstract:

    Fraedrich, S. W., Harrington, T. C., Rabaglia, R. J., Ulyshen, M. D., Mayfield, A. E., III, Hanula, J. L., Eickwort, J. M., and Miller, D. R. 2008. A fungal symbiont of the redbay ambrosia beetle causes a lethal wilt in redbay and other Lauraceae in the southeastern United States. Plant Dis. 92:215-224. Extensive mortality of redbay has been observed in the coastal plain counties of Georgia and southeastern South Carolina since 2003 and northeastern Florida since 2005. We show that the redbay mortality is due to a vascular wilt disease caused by an undescribed Raffaelea sp. that is a fungal symbiont of Xyleborus glabratus, an exotic ambrosia beetle. Trees affected by the disease exhibit wilt symptoms that include a black discoloration of the sapwood. Redbay trees and containerized seedlings died within 5 to 12 weeks after inoculation with the Raffaelea sp. When redbay seedlings were challenged with X. glabratus, the beetles tunneled into 96% of the plants, 70% died, and the Raffaelea sp. was recovered from 91%. X. glabratus and the Raffaelea sp. have also been associated with mortality of Sassafras, and the Raffaelea sp. has been isolated from wilted pondberry and pondspice. Additional inoculation studies have shown that the Raffaelea sp. is pathogenic to Sassafras, spicebush, and avocado, but not to red maple. Female adults of X. glabratus have paired mycangia near the mandibles, and the Raffaelea sp. is routinely isolated from the heads of beetles. The fungus is apparently introduced into healthy redbay during beetle attacks on stems and branches. The wilt currently affecting redbay and Sassafras represents a major threat to other members of the Lauraceae indigenous to the Americas, including avocado in commercial production.

Rabiu Olatinwo - One of the best experts on this subject based on the ideXlab platform.

  • first report of laurel wilt disease caused by raffaelea lauricola on spicebush in louisiana
    Plant Disease, 2019
    Co-Authors: Rabiu Olatinwo, Wood Johnson, J. Hwang, Stephen W Fraedrich
    Abstract:

    In the past two decades, laurel wilt disease has significantly affected members of the Lauraceae in the southeast United States, causing widespread mortality of native redbay (Persea borbonia (L.) Spreng), and incidence of infections in avocado (Persea americana Mill.), Sassafras (Sassafras albidum L.) and swamp bay (Persea palustris [Raf.] Sarg.) (Fraedrich et al., 2008, 2015, Olatinwo, et al. 2019). Laurel wilt is a vascular disease caused by Raffaelea lauricola (T.C. Harr., Fraedrich & Aghayeva), a fungus vectored by a non-native ambrosia beetle Xyleborus glabratus Eichhoff (Fraedrich et al. 2008). In August 2020, we investigated the mortality of a spicebush shrub (Lindera benzoin L.) (3.8 cm diameter at root collar, two m height) located ca. 17 mi northeast of Colfax, Grant Parish, Louisiana (31.750263° N, -92.643694° W). Evaluation of the dead shrub revealed brown, persistent foliage, and black vascular discoloration of the sapwood, typical symptoms of laurel wilt (Fig. S1). Although, beetle holes were observed on the sapwood, no beetle was found in galleries at the time. In the laboratory, a fungus consistently isolated from surface-sterilized sapwood tissues plated on potato dextrose agar (PDA) was identified as R. lauricola based on the morphological characteristics of the isolate (i.e., mucoid growth, conidiophores, and oblong/ovoid shape conidia [Harrington et al. 2008]). The fungal isolate was denoted as SB1. The identity of the fungus was confirmed by positive PCR amplification of the large subunit ribosomal RNA gene region using species-specific primers; rab-lsu-rl_F: CCCTCGCGGCGTATTATAG and rab-lsu-rl_R: GCGGGGCTCCTACTCAAA (Olatinwo, unpublished). The sequence of the isolate SB1 (GenBank Accession no. MW207371) showed 100% homology to the R. lauricola strain CBS 127349 sequence (GenBank Accession no. MH877933). The pathogenicity of SB1 on spicebush was evaluated on four healthy shrubs (average: 1 m height and 40 mm in diameter) at the location from which the original detection was made. Stems of two spicebush shrubs were inoculated with SB1 agar plugs from a 14-day old culture on PDA, while plain PDA plugs were used on the remaining two shrubs as non-inoculated controls. Agar plugs were placed in 5 mm (0.2 in) diameter hole punched on the bark with cork-borer as described by Mayfield et al (2008). After six weeks, the R. lauricola inoculated shrubs were wilted with noticeable blackened tissue discoloration in the sapwood, while the control trees remained healthy (Fig. S2). Raffaelea lauricola was re-isolated from tissue of the two inoculated, symptomatic shrubs, but not from the control trees. The sequence of the re-isolated R. lauricola isolate, denoted as SB3 (GenBank Accession no. MW207372), showed 100% homology to the R. lauricola strain CBS 127349 and isolate SB1. This first documentation of laurel wilt on spicebush in Louisiana is significant because, spicebush berries, leaves, and twigs are food sources for forest animals, birds, and insects including whitetail deer and spicebush swallowtail (Papilio troilus L.). Since its first report on Sassafras in 2014 (Fraedrich et al. 2015), laurel wilt has spread across Louisiana on Sassafras and swamp bay (Olatinwo et al. 2019) and has been confirmed in14 parishes. This report shows the relentless nature of the disease, as the pathogen moves from one vulnerable host to the next, expanding into new locations and threatening forest ecosystems across the southern United States.

  • first report of xyleborus glabratus coleoptera curculionidae scolytinae and laurel wilt in louisiana usa the disease continues westward on Sassafras
    Florida Entomologist, 2015
    Co-Authors: Wood C Johnson, Rabiu Olatinwo, Thomas C. Harrington, Roger D Menard, Susan G Best
    Abstract:

    Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae: Scolytinae) and Sassafras trees that died from laurel wilt were discovered in a 3-parish area of northern Louisiana, USA, in Sep 2014. Redbay, a species that has been severely affected by the disease in the coastal plains forests of the southeastern USA, is not found in this area of northern Louisiana, suggesting that Sassafras is attractive to X. glabratus and an adequate reproductive host for the beetle. This is the first report of X. glabratus and laurel wilt in Louisiana and the first report of the beetle and disease west of the Mississippi River. Sumario En septiembre del 2014, Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae: Scolytinae) y arboles de sasafras que murieron a causa de la marchitez del laurel fueron descubiertos en un area de 3 municipios del norte de Louisiana, EE.UU. El aguacatillo ( Persea borbonia ), una especie que se ha visto gravemente afectada por la enfermedad en los bosques de la llanura costero del sudeste de EE.UU., no se encuentra en esta zona del norte de Louisiana, lo que sugiere que el sasafras es atractivo para X. glabratus y un hospedero reproductivo adecuado para el escarabajo. Este es el primer informe de X. glabratus y la marchitez del laurel en Louisiana y el primer informe del escarabajo y la enfermedad al oeste del rio Mississippi. View this article in BioOne

  • first report of laurel wilt caused by raffaelea lauricola on Sassafras Sassafras albidum in alabama
    Plant Disease, 2013
    Co-Authors: Rabiu Olatinwo, C Barton, Wood Johnson, Stephen W Fraedrich, J. Hwang
    Abstract:

    Laurel wilt, caused by Raffaelea lauricola, a fungal symbiont of the redbay ambrosia beetle, Xyleborus glabratus, is responsible for extensive mortality of native redbays (Persea borbonia and P. palustris) in the coastal plains of the southeastern United States (1). The wilt also affects the more widespread Sassafras, Sassafras albidum, particularly in areas where diseased redbays are common and populations of X. glabratus are high. Because Sassafras stems were thought to lack chemicals that are attractive to the beetle, and Sassafras tends to be widely scattered in forests, it was believed that the advance of the laurel wilt epidemic front might slow once it reached the edge of the natural range of redbay, which is restricted to the coastal plains of the Gulf and Atlantic Coasts (2). In July and August of 2011, wilt-like symptoms (i.e., wilted and dead leaves, and streaks of black discoloration in the xylem) were observed on 1 to 10 Sassafras trees (15 to 23 cm diameter; 6 to 9 m height) at each of three...

James L. Hanula - One of the best experts on this subject based on the ideXlab platform.

  • Variation in Manuka Oil Lure Efficacy for Capturing Xyleborus glabratus (Coleoptera: Curculionidae: Scolytinae), and Cubeb Oil as an Alternative Attractant
    Environmental Entomology, 2013
    Co-Authors: James L. Hanula, Brian T Sullivan, David Wakarchuk
    Abstract:

    Redbay ambrosia beetle, Xyleborus glabratus Eichoff, is an exotic species to North America vectoring a deadly vascular wilt disease of redbay (Persea borbonia (L.) Spreng), swampbay (P. palustris (Raf.) Sarg.), avocado (P. americana Mill.), and Sassafras (Sassafras albidum (Nutt.) Nees). Xyleborus glabratus is attracted to manuka oil lures, which are commercially available, and phoebe oil. Variable efÞcacy of manuka oil lures and insufÞcient availability of phoebe oil prompted us to investigate the reasons behind changes in manuka oil lure efÞcacy and to test cubeb oil, a readily available essential oil from Piper cubeba L. seeds, as an alternative attractant. Attraction, release rates and durations, and volatile composition of manuka oil lures manufactured in 2008 were compared with manuka oil lures manufactured in 2012, and to whole and a distilled fraction of cubeb oil. Manuka oil lures from 2008 were more attractive to X. glabratus than controls for 8 wk, whereas lures from 2012 were attractive for only 2 wk. Cubeb oil and the distilled fraction of it were as attractive as or more attractive than manuka oil in three trials. In gravimetric studies, manuka oil lures from 2008 and cubeb oil lures continued to release volatiles for 57 d, whereas lures from 2012 stopped after 16 d. The chemical composition of volatiles released from new manuka oil lures from 2008 was similar to 2012; however, a preservative (butylated hydroxytoluene) was detected in the 2008 lures. Cubeb oil was an effective attractant for X. glabratus that lasted 8 Ð9 wk when released from bubble lures.

  • biology and host associations of redbay ambrosia beetle coleoptera curculionidae scolytinae exotic vector of laurel wilt killing redbay trees in the southeastern united states
    Journal of Economic Entomology, 2008
    Co-Authors: James L. Hanula, Stephen W Fraedrich, Robert J Rabaglia
    Abstract:

    Abstract The redbay ambrosia beetle, Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae: Scolytinae), and its fungal symbiont, Raffaelea sp., are new introductions to the southeastern United States responsible for the wilt of mature redbay, Persea borbonia (L.) Spreng., trees. In 2006 and 2007, we investigated the seasonal flight activity of X. glabratus, its host associations, and population levels at eight locations in South Carolina and Georgia where infestations ranged from very recent to at least several years old. Adults were active throughout the year with peak activity in early September. Brood development seems to take 50–60 d. Wood infested with beetles and infected with the Raffaelea sp. was similar in attraction to uninfested redbay wood, whereas both were more attractive than a nonhost species. Sassafras, Sassafras albidium (Nutt.) Nees, another species of Lauraceae, was not attractive to X. glabratus and very few beetle entrance holes were found in Sassafras wood compared with redbay. C...

  • biology and host associations of redbay ambrosia beetle coleoptera curculionidae scolytinae exotic vector of laurel wilt killing redbay trees in the southeastern united states
    Journal of Economic Entomology, 2008
    Co-Authors: James L. Hanula, Stephen W Fraedrich, Robert J Rabaglia
    Abstract:

    The redbay ambrosia beetle, Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae: Scolytinae), and its fungal symbiont, Raffaelea sp., are new introductions to the southeastern United States responsible for the wilt of mature redbay, Persea borbonia (L.) Spreng., trees. In 2006 and 2007, we investigated the seasonal flight activity of X. glabratus, its host associations, and population levels at eight locations in South Carolina and Georgia where infestations ranged from very recent to at least several years old. Adults were active throughout the year with peak activity in early September. Brood development seems to take 50-60 d. Wood infested with beetles and infected with the Raffaelea sp. was similar in attraction to uninfested redbay wood, whereas both were more attractive than a nonhost species. Sassafras, Sassafras albidium (Nutt.) Nees, another species of Lauraceae, was not attractive to X. glabratus and very few beetle entrance holes were found in Sassafras wood compared with redbay. Conversely, avocado, Persea americana Mill., was as attractive to X. glabratus as swampbay, P. palustris (Raf.) Sarg., and both were more attractive than the nonhost red maple, Acer rubrum L. However, avocado had relatively few entrance holes in the wood. In 2007, we compared X. glabratus populations in areas where all mature redbay have died to areas where infestations were very active and more recent. Trap catches of X. glabratus and numbers of entrance holes in trap bolts of redbay were correlated with the number of dead trees with leaves attached. Older infestations where mature host trees had been eliminated by the wilt had low numbers of beetles resulting in trap catches ranging from 0.04 to 0.12 beetles per trap per d compared with 4-7 beetles per trap per d in areas with numerous recently dead trees. Our results indicate beetle populations drop dramatically after suitable host material is gone and provide hope that management strategies can be developed to restore redbay trees. The lack of attraction of X. glabratus to Sassafras suggests that spread of X. glabratus may slow once it is outside the range of redbay.

  • a fungal symbiont of the redbay ambrosia beetle causes a lethal wilt in redbay and other lauraceae in the southeastern united states
    Plant Disease, 2008
    Co-Authors: Stephen W Fraedrich, Thomas C. Harrington, Robert J Rabaglia, James L. Hanula, Michael D Ulyshen, J M Eickwort, Daniel R Miller
    Abstract:

    Fraedrich, S. W., Harrington, T. C., Rabaglia, R. J., Ulyshen, M. D., Mayfield, A. E., III, Hanula, J. L., Eickwort, J. M., and Miller, D. R. 2008. A fungal symbiont of the redbay ambrosia beetle causes a lethal wilt in redbay and other Lauraceae in the southeastern United States. Plant Dis. 92:215-224. Extensive mortality of redbay has been observed in the coastal plain counties of Georgia and southeastern South Carolina since 2003 and northeastern Florida since 2005. We show that the redbay mortality is due to a vascular wilt disease caused by an undescribed Raffaelea sp. that is a fungal symbiont of Xyleborus glabratus, an exotic ambrosia beetle. Trees affected by the disease exhibit wilt symptoms that include a black discoloration of the sapwood. Redbay trees and containerized seedlings died within 5 to 12 weeks after inoculation with the Raffaelea sp. When redbay seedlings were challenged with X. glabratus, the beetles tunneled into 96% of the plants, 70% died, and the Raffaelea sp. was recovered from 91%. X. glabratus and the Raffaelea sp. have also been associated with mortality of Sassafras, and the Raffaelea sp. has been isolated from wilted pondberry and pondspice. Additional inoculation studies have shown that the Raffaelea sp. is pathogenic to Sassafras, spicebush, and avocado, but not to red maple. Female adults of X. glabratus have paired mycangia near the mandibles, and the Raffaelea sp. is routinely isolated from the heads of beetles. The fungus is apparently introduced into healthy redbay during beetle attacks on stems and branches. The wilt currently affecting redbay and Sassafras represents a major threat to other members of the Lauraceae indigenous to the Americas, including avocado in commercial production.