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Laurel wilt (Lw) is a fatal disease. It is a vascular pathogen and is considered a major threat to the avocado industry in Florida. Many of the symptoms of Lw resemble those that are caused by other diseases or stress factors. In this study, the best wavelengths with which to discriminate plants affected by Lw from stress factors were determined and classified. Visible-near infrared (400–950 nm) spectral data from healthy trees and those with Lw, Phytophthora, or salinity damage were collected using a handheld spectroradiometer. The total number of wavelengths was averaged in two ranges: 10 nm and 40 nm. Three classification methods, stepwise discriminant (STEPDISC) analysis, multilayer perceptron (MLP), and radial basis function (RBF), were applied in the early stage of Lw infestation. The classification results obtained for MLP, with percent accuracy of classification as high as 98% were better than STEPDISC and RBF. The MLP neural network selected certain wavelengths that were crucial for correctly classifying healthy trees from those with stress trees. The results showed that there were sufficient spectral differences between laurel wilt, healthy trees, and trees that have other diseases; therefore, a remote sensing technique could diagnose Lw in the early stage of infestation., The author would like to thank the Florida Dept. of Agriculture and Consumer Services, USDA Specialty Block Grant No. 019730 for partially funding this study and the Ministry of Higher Education and Scientific Research of Republic of Iraq for supporting the graduate student working on this project.

The redbay ambrosia beetle Xyleborus glabratus is the vector of the symbiotic fungus, Raffaelea lauricola that causes laurel wilt, a highly lethal disease to members of the Lauraceae family. Pioneer X. glabratus beetles infect live trees with R. lauricola, and only when tree health starts declining more X. glabratus are attracted to the infected tree. Until now this sequence of events was not well understood. In this study, we investigated the temporal patterns of host volatiles and phytohormone production and vector attraction in relation to laurel wilt symptomology. Following inoculations with R. lauricola, volatile collections and behavioral tests were performed at different time points. Three days after infection (DAI), we found significant repellency of X. glabratus by leaf odors of infected swamp bay Persea palustris as compared with controls. However, at 10 and 20 DAI, X. glabratus were more attracted to leaf odors from infected than non-infected host plants. GC-MS analysis revealed an increase in methyl salicylate (MeSA) 3 DAI, whereas an increase of sesquiterpenes and leaf aldehydes was observed 10 and 20 DAI in leaf volatiles. MeSA was the only behaviorally active repellent of X. glabratus in laboratory bioassays. In contrast, X. glabratus did not prefer infected wood over healthy wood, and there was no associated significant difference in their volatile profiles. Analyses of phytohormone profiles revealed an initial increase in the amount of salicylic acid (SA) in leaf tissues following fungal infection, suggesting that the SA pathway was activated by R. lauricola infection, and this activation caused increased release of MeSA. Overall, our findings provide a better understanding of X. glabratus ecology and underline chemical interactions with its symbiotic fungus. Our work also demonstrates how the laurel wilt pathosystem alters host defenses to impact vector behavior and suggests manipulation of host odor by the fungus that attract more vectors.

We summarize the information available on ambrosia beetle species that have been associated in Florida with Raffaelea lauricola T.C. Harr., Fraedrich & Aghayeva, the primary symbiont of Xyleborus glabratus Eichhoff and cause of laurel wilt. In total, 14 species in Ambrosiodmus, Euwallacea, Premnobius, Xyleborus, Xyleborinus, and Xylosandrus were either reared from laurel wilt-affected host trees or trapped in laurel wilt-affected stands of the same, and assayed for R. lauricola. In six collections from native species in the southeastern United States [Persea borbonia (L.), Persea palustris (Raf.) Sarg., and Persea humilis Nash] and four from avocado (Persea americana Mill.), extracted mycangia or heads (taxa with mandibular mycangia) or intact bodies (taxa with mycangia in other locations) were surface-disinfested before assays on a semi-selective medium for the isolation of Raffaelea (CSMA+). Raffaelea lauricola was identified based on its characteristic phenotype on CSMA+, and the identity of a random subset of isolates was confirmed with taxon-specific microsatellite markers. The pathogen was recovered from 34% (246 of 726) of the individuals that were associated with the native Persea spp., but only 6% (58 of 931) of those that were associated with avocado. Over all studies, R. lauricola was recovered from 10 of the ambrosia beetle species, but it was most prevalent in Xyleborus congeners. This is the first record of R. lauricola in Ambrosiodmus lecontei Hopkins, Xyleborinus andrewesi (Blandford), and Xyleborus bispinatus Eichhoff. The potential effects of R. lauricola's promiscuity are discussed.

The redbay ambrosia beetle, Xyleborus glabratus Eichhoff, is the principal vector of laurel wilt disease in North America. Lures incorporating essential oils of manuka plants ( Leptospermum scoparium J. R. Forster & G. Forster) or cubeb seeds ( Piper cubeba L.f.) are the most effective in-flight attractants to date. Using grids of traps baited with these essential oil lures, we evaluated 1) the effect of trap distance from a source beetle population on beetle captures, 2) the feasibility of trapping out low-density beetle populations, and 3) the effect of trap spacing on beetle captures. In the first experiment, increasing trap distance up to 300 m from a source X. glabratus population had little effect on beetle captures. In a second experiment conducted in a study area with very low beetle densities, trapping for 5 mo prior to deploying freshly cut, uninfested redbay bolts had no effect on subsequent attack densities. In a third experiment, numbers of X. glabratus captured in traps in the center of a grid of nine traps spaced 1 or 5 m apart were compared with lone baited or unbaited traps 30 m away. Relative to the more distant traps, the grid of baited traps neither increased captures in the unbaited center trap nor decreased captures in the baited center trap, regardless of spacing. The results suggest that the effective trapping distance of essential oil lures for X. glabratus is

Invasive wood borers vectoring pathogenic fungi have nearly exterminated several North American tree species, and it is unclear whether landscape dominant trees, such as pines, will face similar threats in the future. This paper explores the economic impacts of a hypothetical arrival of a destructive ambrosia beetle “X” (Coleoptera: Curculionidae) that infests loblolly pine (Pinus taeda L.) forests in the Southeastern United States. We develop an economic framework for pre-invasion assessment that incorporates fluctuating economic and environmental conditions for a representative loblolly pine stand and biological assumptions from the ongoing laurel wilt epidemic. Assuming an initial annual probability of arrival of a pine infesting ambrosia beetle to be between 0.04 and 0.07, we determine that, on average, the timber economic benefits for a forest landowner are $5325.3 ha-1, with a harvest time of 17.8 years. Our results indicate that an increase in enforcement consistent with an international phytosanitary standard that partially prevents the arrival of ambrosia beetles (30% arrival reduction) would have a strong, positive impact for forest landowners. On average, economic revenues increase to $6116.4 ha-1 and the harvest age is extended to 19 years. On average, the economic losses for forest landowners with no control of ambrosia beetle X would be $791 ha−1, with a harvest time reduction of 1.2 years. The upper-bound regional cost savings from pine-dominated forestry would be roughly $4.6 billion dollars if invasion preventative measures are in place. These benefits vastly outweigh the cost of programs that reduce the expected arrival of exotic ambrosia beetles.

Xyleborus glabratus (Coleoptera: Curculionidae: Scolytinae) is a non-native pest that transmits the causal pathogen of laurel wilt disease to plants belonging to the Lauraceae. To improve the current monitoring and survey techniques of X. glabratus, various trapping and flight behavior studies were conducted in natural areas with host species in Alachua County, Florida. Daylight flight rhythm studied at Austin Cary Memorial Forest twice in Sep 2010 using sticky traps baited with manuka lures showed that X. glabratus flies mostly between 1600 and 1800 h daylight saving time. Flight height of the beetle was determined in a trapping study using ladder-like traps. The largest number of beetles was trapped at heights of 35–100 cm above the ground. Seasonality of X. glabratus was studied in Florida from Mar 2010–Dec 2011. Three peaks of trap catches occurred during Apr 2010, Oct 2010 and Mar 2011. To find the optimal Lindgren funnel trap design for X. glabratus, a study was conducted using 4, 8, 12 and...

Redbay ambrosia beetle (RAB), Xyleborus gla bratus Eichhoff (Coleoptera: Curculionidae: Sco lytinae), a native of Asia, was first discovered in the USA near Savannah, Georgia in 2002 (Haack 2001; Rabaglia et al. 2006). RAB is an effective vector of Raffaelea lauricola T.C. Harr., Fraedrich & Aghayeva (Harrington et al. 2008) that causes laurel wilt (LW), a lethal disease of several trees in the Lauraceae in the southeastern USA (Crane et al. 2008; Mayfield et al. 2008). Ambrosia beetle adults bore through the bark and into the xy lem (wood) where they lay eggs, then adults and larvae cultivate and feed on symbiotic ambrosia fungi that grow in the galleries. Native Persea (Laurales: Lauraceae) species appear to be pre ferred hosts. LW is responsible for high mortality of redbay [P borbonia (L.) Spreng.], swampbay [P palustris (Raf.) Sarg.], and sassafras [Sassa fras albidum (Nuttall) Nees] in Alabama, Flor ida, Georgia, Mississippi, North Carolina and South Carolina (Fraedrich et al. 2008; Hanula et al. 2008; Gramling 2010). As LW encroaches upon the Lake Wales Ridge ecosystem in south central Florida, silkbay (P. humilis Nash) is also showing susceptibility to LW and is dying. Addi tional species affected by LW include avocado (P. americana Mill.), spicebush [Lindera benzoin (L.) Blume], and other woody Lauraceae (Fraedrich et al. 2008) (Table 1). The susceptibility of 5 avocado cultivars of Mexican, Guatemalan or West Indian origin to RAB and LW was demonstrated by Mayfield et al. (2008). However, with more than 23 West In dian cultivars grown in Florida, it is necessary to determine their susceptibility. Moreover, as an adventive species to the North American conti nent, RAB might affect other valuable New World species. Most Persea species are of Mexican, Cen tral American, or South American origin. These Persea may have significant value in germplasm collections, some have been discovered recently, and some have resistance to diseases that afflict their commercial relative, the avocado (Skutch et l. 1992; Scora & Bergh 1992; Zentmyer & Schieber 1992). Thus, their susceptibility to RAB and LW warrants evaluation. Another member of the Lauraceae of much concern is the California bay laurel [Umbellularia californica (Hook. & Arn.) Nutt.], a dominant hardwood species of the U.S. Pacific Coast. Through inoculation experi ments, Fraedrich (2008) demonstrated that U. californica is susceptible to LW. With continued westward spread of LW, the host status of U. cali fornica needs to be confirmed. The 3 studies presented here evaluate sus ceptibility to RAB and LW in: 1) 13 West Indian avocado cultivars; 2) 10 non-commercial Persea spp., 1 Beilschmidia sp. (a genus related to Per sea), and 3) U. californica. First, no-choice ex periments were conducted to determine if RAB would bore into avocado cultivars not screened previously by Mayfield et al. (2008) and follow ing similar methodology. Avocado cultivars 'Ber necker', 'Beta', 'Brooks late', 'Choquette', 'Don nie', 'Dupuis', 'Hall', 'Loretta', 'Lula', 'Monroe', 'Simmonds', 'Tower 2' and 'Waldin' (4 plants each) were planted in 10-gallon pots in a screenhouse at he Plant Sciences Research and Education Unit, University of Florida (UF), Citra, Florida in VI 2008. Two plants of each cultivar were infested by enclosing 4 newly emerged 9 RAB (UF colony reared) within a mesh sleeve on the lower trunk. Two plants per cultivar were uninfested controls. Entrance holes and perseitol (white exudate from wounds) were monitored for 4 wk. Severity of wilt symptoms was scored using the following LW in dex: 0 = no wilt; 1 = wilt, no leaf necrosis; 2 = wilt, 10% necrosis or defoliation; 3 = wilt, 30% necrosis/ defoliation; 4 = 50% necrosis/defoliation; 5 = 75% necrosis/defoliation; 6 = 100% necrosis/defoliation

Laurel wilt is a destructive disease caused by the fungus Raffaelea lauricola, which is transmitted by the invasive redbay ambrosia beetle, Xyleborus glabratus. Here we document ambrosia beetles that emerged from wilted avocado trees throughout Florida. In addition, the ambrosia beetle fauna associated with wilted swampbay trees in Miami-Dade was studied. Fourteen species of scolytine beetles were found associated with avocado wood from different parts of Florida. Multiple species of ambrosia beetles were found breeding in avocado and swampbay wood infected by R. lauricola with or without the presence of its primary vector, X. glabratus. Work is under way to determine whether other ambrosia beetle species can carry R. lauricola and transmit this pathogen to healthy avocado and swampbay trees. Resumen: La marchitez del laurel es una enfermedad destructiva causada por el hongo Raffaelea lauricola, el cual es transmitido por el escarabajo de ambrosia, Xyleborus glabratus. Se presenta un registro de las especies de escarabajos de ambrosia que emergieron de arboles de aguacate marchitos, colectados en diferentes partes de Florida. Tambien se estudio la fauna de escarabajos de ambrosia asociados a Persea palustris en el condado de Miami-Dade. Catorce especies de escarabajos de ambrosia fueron encontradas reproduciendose en madera de aguacate en diferentes partes de Florida. Varias especies de escarabajos de ambrosia se encontraron en arboles infectados con R. lauricola. Sin embargo, su principal vector, X. glabratus, no se encontro en todos los arboles infectados. Se esta trabajando para determinar si otras especies de escarabajos de ambrosia pueden transmitir este patogeno a plantas sanas de aguacate y P. palustris.View this article in BioOne

Avocado, Persea americana, is an important fruit crop in the tropics and warm subtropics. Laurel wilt, caused by Raffaelea lauricola, is a systemic vascular wilt of avocado that spread recently to Florida, an important producing state in the USA. As fruit and seed of avocado produced in Florida are sold in other states and countries where this crop is produced, there is concern that commerce in these commodities might spread this disease. Potted, fruit-bearing trees were artificially inoculated with R. lauricola, and plants were systemically colonized by the fungus. In no instance did infection progress further than the hilum (87 total fruit), as determined by re-isolation of R. lauricola on a semi-selective medium or its detection, with qPCR and high fidelity PCR, of diagnostic small subunit (SSU) 18s rDNA. Thus, it would apparently be safe to propagate avocado with seed from trees affected by this disease. Pedicels/peduncles and hila associated with these fruit were colonized by the pathogen. The latter tissues would be associated with/attached to marketed fruit, but they do not harbour the pathogen’s ambrosia beetle vector, Xyleborus glabratus. Thus, commerce in avocado fruit appears to be a negligible risk for expanding the geographic range of laurel wilt.

Raffaelea lauricola causes laurel wilt of avocado, Persea americana. Host × pathogen interactions were examined with light and scanning electron microscopy. The susceptible avocado cultivar ‘Simmonds’ was inoculated and examined 5 cm above the inoculation site 3, 7, 14, 21, and 42 days after inoculation (dai). No external symptoms were observed at 3 and 7 dai, and there were no anatomical differences when compared with the mock-inoculated plants. By 14 dai, external symptoms were present and dark discoloration had developed in sapwood. Tylose development increased significantly by 14 dai, and was positivity correlated with disease severity (P < 0.05). By 14 dai, gels formed in xylem vessels, fibers, and adjacent parenchyma cells; they were associated with xylem blockage and composed of phenols, pectin, and lipids, as suggested by, respectively, toluidine blue O, ruthenium red, and Sudan III stains. With a chitin-specific stain, fluorescein-conjugated wheat germ agglutinin, infrequent mycelia, and conidia of R. lauricola were visualized within xylem lumena and fibers, regardless of sample date. Understanding how avocado responds to the presence of this pathogen could assist the development of laurel wilt-resistant avocado genotypes and inform efforts to manage this disease with other measures.

Redbay ambrosia beetle, Xyleborus glabratus Eichhoff, is an exotic wood-borer that vectors the fungal agent (Raffaelea lauricola) responsible for laurel wilt. Laurel wilt has had severe impact on forest ecosystems in the southeastern United States, killing a large proportion of native Persea trees, particularly redbay (P. borbonia) and swampbay (P. palustris), and currently poses an economic threat to avocado (P. americana) in Florida. To control the spread of this lethal disease, effective attractants are needed for early detection of the vector. Two 12-wk field tests were conducted in Florida to evaluate efficacy and longevity of manuka and phoebe oil lures, and to relate captures of X. glabratus to release rates of putative sesquiterpene attractants. Two trap types were also evaluated, Lindgren funnel traps and sticky panel traps. To document lure emissions over time, a separate set of lures was aged outdoors for 12 wk and sampled periodically to quantify volatile sesquiterpenes using super-Q adsorbant and gas chromatography-mass spectroscopy analysis. Phoebe lures captured significantly more X. glabratus than manuka lures, and sticky traps captured more beetles than funnel traps. Phoebe lures captured X. glabratus for 10-12 wk, but field life of manuka lures was 2-3 wk. Emissions of alpha-copaene, alpha-humulene, and cadinene were consistently higher from phoebe lures, particularly during the 2-3 wk window when manuka lures lost efficacy, suggesting that these sesquiterpenes are primary kairomones used by host-seeking females. Results indicate that the current monitoring system is suboptimal for early detection of X. glabratus because of rapid depletion of sesquiterpenes from manuka lures.

The redbay ambrosia beetle, Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae: Scolytinae), is an exotic wood-boring insect that vectors Raffaelea lauricola, the fungal pathogen responsible for laurel wilt, a lethal disease of trees in the Lauraceae. First detected in the U.S. near Savannah, GA in 2002, X. glabratus has since spread throughout the southeastern coastal plain causing high mortality in native Persea species, particularly redbay (P. borbonia) and swampbay (P. palustris). Currently, breeding populations of X. glabratus pose an imminent threat to the avocado (P. americana) industry in south Florida. There is a critical need for effective attractants to detect, monitor, and control the spread of this invasive pest. In an effort to identify host-based attractants for dispersing female X. glabratus, we conducted a comparative study of the volatile chemicals emitted from wood of six species of Lauraceae found in Florida: avocado (Persea americana), redbay (P. borbonia), swampbay (P. ...

The redbay ambrosia beetle (RAB), Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae: Scolytinae), is an adventive pest of Lauraceae in the southeastern U.S. This wood-boring insect vectors a lethal fungus, Raffaelea lauricola T. C. Harr., Fraedrich & Aghayeva, the causal agent of laurel wilt (LW) disease. The vector-pathogen complex is responsible for extensive mortality of native Persea trees in South Carolina, Georgia, and northern Florida, and now poses an imminent threat to the avocado (Persea americana Mill.) industry in south Florida. While chemical control of the vector is not viewed as the primary solution, control tactics should be made available to Florida avocado growers. Field and laboratory tests were conducted using avocado bolts, potted avocado trees, and field grown swampbay trees (Persea palustris (Raf.) Sarg.) treated with contact and systemic insecticides. Zeta-cypermethrin + bifenthrin and lambda-cyhalothrin + thiamethoxam provided the most consistent control of Scolytin...

The laurel wilt pathogen Raffaelea lauricola was hypothesized to have been introduced to the southeastern USA in the mycangium of the redbay ambrosia beetle, Xyleborus glabratus, which is native to Asia. To test this hypothesis adult X. glabratus were trapped in Taiwan and on Kyushu Island, Japan, in 2009, and dead beetles were sent to USA for isolation of fungal symbionts. Individual X. glabratus were macerated in glass tissue grinders, and the slurry was serially diluted and plated onto malt agar medium amended with cycloheximide, a medium semiselective for Ophiostoma species and their anamorphs, including members of Raffaelea. R. lauricola was isolated from 56 of 85 beetles in Taiwan and 10 of 16 beetles in Japan at up to an estimated 10 000 CFUs per beetle. The next most commonly isolated species was R. ellipticospora, which also has been recovered from X. glabratus trapped in the USA, as were two other fungi isolated from beetles in Taiwan, R. fusca and R. subfusca. Three unidentified Raffaelea spp. and three unidentified Ophiostoma spp. were isolated rarely from X. glabratus collected in Taiwan. Isolations from beetles similarly trapped in Georgia, USA, yielded R. lauricola and R. ellipticospora in numbers similar to those from beetles trapped in Taiwan and Japan. The results support the hypothesis that R. lauricola was introduced into the USA in mycangia of X. glabratus shipped to USA in solid wood packing material from Asia. However differences in the mycangial mycoflora of X. glabratus in Taiwan, Japan and USA suggest that the X. glabratus population established in USA originated in another part of Asia.

The redbay ambrosia beetle, Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae: Scolytinae), is an exotic wood-boring insect that vectors laurel wilt, a lethal vascular disease of trees in the Lauraceae, including avocado (Persea americana) and native Persea species (redbay, swampbay). As part of research to identify host-based attractants for X. glabratus, we discovered that a diverse array of non-target ambrosia beetles was attracted to the same substrates as X. glabratus. During Sep–Dec 2009, several field tests were conducted in north Florida (in woodlands with advanced stages of laurel wilt) with traps baited with commercial lures of the essential oils, manuka and phoebe, and with freshly-cut wood bolts of avocado (a known host) and lychee (Litchi chinensis, a non-host high in the sesquiterpene αcopaene, a putative host attractant). In addition, manuka-baited traps were deployed in avocado groves in south Florida to monitor for potential spread of X. glabratus. The combined trapping res...

Xyleborus volvulus is a polyphagous beetle that can carry Raffaelea lauricola, a phytopathogenic fungus that causes laurel wilt disease. In Mexico, the insect has been associated with damage to cedar, cacao, and avocado plantations. Here, we report mango trees infested by X. volvulus in a mango orchard with a history of having avocado trees were removed due to infestation by X. volvulus.

Laurel Wilt is caused by a recently identified fungal pathogen infecting plants in the Lauraceae. Laurel Wilt is transmitted by Xyleborus glabratus (Redbay Ambrosia Beetle), which was recently introduced to the southeastern United States from Asia. As the insect expands its range in the US, so too has the disease. A query of the NatureServe Explorer database was used to identify the conservation status of native plant species and recognized plant communities that may be affected by Laurel Wilt. Laurel Wilt affects at least nine plant species, and all fifteen species in the Lauraceae currently found in North America may ultimately prove to be hosts for the disease. Four of the twelve native lauraceous species had been identified as vulnerable to extirpation or extinction, prior to the introduction of Laurel Wilt. There are 55 plant communities in the US and Canada that have a member of the Lauraceae as a dominant or diagnostic species. The majority of these plant communities have been identified a...

Harrington, T. C., and Fraedrich, S. W. 2010. Quantification of propagules of the laurel wilt fungus and other mycangial fungi from the redbay ambrosia beetle, Xyleborus glabratus. Phytopathology 100:11181123. The laurel wilt pathogen, Raffaelea lauricola, is a fungal symbiont of the redbay ambrosia beetle, Xyleborus glabratus, which is native to Asia and was believed to have brought R. lauricola with it to the southeastern United States. Individual X. glabratus beetles from six populations in South Carolina and Georgia were individually macerated in glass tissue grinders and serially diluted to quantify the CFU of fungal symbionts. Six species of Raffaelea were isolated, with up to four species from an individual adult beetle. The Raffaelea spp. were apparently within the protected, paired, mandibular mycangia because they were as numerous in heads as in whole beetles, and surface-sterilized heads or whole bodies yielded as many or more CFU as did nonsterilized heads or whole beetles. R. lauricola was isolated from 40 of the 41 beetles sampled, and it was isolated in the highest numbers, up to 30,000 CFU/beetle. Depending on the population sampled, R. subalba or R. ellipticospora was the next most frequently isolated species. R. arxii, R. fusca, and R. subfusca were only occasionally isolated. The laurel wilt pathogen apparently grows in a yeast phase within the mycangia in competition with other Raffaelea spp.

Like other members of the tribe Xyleborini, Xyleborus bispinatus Eichhoff can cause economic damage in the Neotropics. X. bispinatus has been found to acquire the laurel wilt pathogen Raffaelea lauricola (T. C. Harr., Fraedrich & Aghayeva) when breeding in a host affected by the pathogen. Its role as a potential vector of R. lauricola is under investigation. The main objective of this study was to evaluate three artificial media, containing sawdust of avocado (Persea americana Mill.) and silkbay (Persea humilis Nash.), for rearing X. bispinatus under laboratory conditions. In addition, the media were inoculated with R. lauricola to evaluate its effect on the biology of X. bispinatus. There was a significant interaction between sawdust species and R. lauricola for all media. Two of the media supported the prolific reproduction of X. bispinatus, but the avocado-based medium was generally more effective than the silkbay-based medium, regardless whether or not it was inoculated with R. lauricola. R. lauricola had a neutral or positive effect on beetle reproduction. The pathogen was frequently recovered from beetle galleries, but only from a few individuals which were reared on inoculated media, and showed limited colonization of the beetle’s mycangia. Two media with lower water content were most effective for rearing X. bispinatus.

The avocado (Persea americana Miller) brings in an estimated $100 million annually to the state of Florida. While its largest threat in recent years continues to be laurel wilt, caused by Raffaelea lauricola, there is a myriad of other diseases affecting avocado. Although powdery mildew on avocadoes is rare, the novel species Podosphaera perseae-americanae has been recently reported in Indonesia (Siahaan et al. 2016). In April 2017, leaf samples from P. americana cv. ‘Waldin’ grown in a greenhouse exhibiting symptoms typical of powdery mildew were submitted to the Florida Extension Plant Diagnostic Clinic in Homestead, FL. Symptoms included white powdery colonies growing on abaxial surfaces of younger leaves, while older damage included veiny, chlorotic lesions. Other cultivars in the same greenhouse including ‘Toro Canyon’, ‘Duke 7’ and ‘Dusa’ did not appear to be susceptible to powdery mildew. Microscopic observations revealed hyaline, ellipsoid to cylindrical conidia measuring 25 to 40 × 15 to 40 μm (a...

This article describes and provides preliminary estimates of the potential economic losses that could result from an incursion of the recently discovered exotic laurel wilt disease caused by Raffaelea lauricola, in the main avocado (Persea americana) growing area of Florida. Estimates are provided for the direct losses as well as the indirect or “spillover” losses that could occur across the rest of the regional economy. The Impact Analysis for Planning (IMPLAN) input-output multipliers were used in assessing the regional impacts. The results of the investigation indicate that the direct loss to the industry in terms of lost sales, property damage, and increased management costs could range from $356 million in a do-nothing situation to about $183 million if damage control measure were 50% effective. If increased management costs and decreased property values are ignored, the adverse impact on the regional economy could range from $54 million in a do-nothing situation to $27 million in a case in which the treatments result in only a 50% reduction in avocado production.

Lindera melissifolia (Pondberry) is a federally endangered shrub that reproduces primarily by ramets from rhizomes and occurs in scattered clonal populations in bottomland forests of the southeastern US. Like other members of the Lauraceae indigenous to the US, Pondberry is susceptible to laurel wilt, a lethal disease caused by the fungal pathogen, Raffaelea lauricola. We conducted studies to determine the impact of laurel wilt on Pondberry colonies. We grew Pondberry in pots and in raised beds for 2–5 y; during this time, multiple ramets developed around the original plants. We subsequently inoculated single Pondberry stems in colonies with R. lauricola, or mock-inoculated stems with sterile deionized water. Stems inoculated with R. lauricola began to show symptoms within 2 weeks and completely wilted in ∼4 weeks. In pot studies, R. lauricola spread through rhizomes and caused wilt in an average of 77% of ramets in one experiment and 59% in another. The wilt also spread rapidly through connecting rhizomes in field experiments, killing as many as 59 ramets at distances of up to 4 m from the inoculated stems. Although laurel wilt has been rarely documented in Pondberry, our study demonstrates that when infections by R. lauricola occur, they can have detrimental effects to Pondberry colonies.

Redbay ambrosia beetle, Xyleborus glabratus Eichhoff, is a native of Southeast Asia recently established in coastal forests of Georgia, SC and Florida. It vectors a wilt fungus, Raffaelea sp., lethal to redbay trees, Persea borbonia L. Spreng, and certain other Lauraceae. No practical monitoring system exists for this beetle so we conducted studies to identify host attractants and develop lures. Volatiles were collected from redbay wood and bark by steam distillation, direct solvent extraction, and dynamic headspace sampling with a Poropak Q cartridge. Steam, methanol, and pentane extracts were tested as baits in trapping trials but were not attractive to X. glabratus. Major constituents in Poropak aerations identified by gas chromatography-mass spectrometry included α-pinene, β-pinene, δ-3-carene, eucalyptol, p-cymene, α-copaene, terpinene-4-ol, linalool, calamenene, and nonanoic acid. We assayed several of these compounds (including eucalyptol, p-cymene, terpinene-4-ol, linalool, nonanoic acid,...

The non-native redbay ambrosia beetle, Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae: Scolytinae), has recently emerged as a significant pest of southeastern U.S. coastal forests. Specifically, a fungal symbiont (Raffaelea sp.) of X. glabratus has caused mortality of redbay (Persea borbonia) and sassafras (Sassafras albidum) trees in the region; several other Lauraceae species also seem susceptible. Although the range of X. glabratus continues to expand rapidly, little is known about the species' biology and behavior. In turn, there has been no broad-scale assessment of the threat it poses to eastern U.S. forests. To provide a basic information framework, we performed analyses exploiting relevant spatio-temporal data available for X. glabratus. First, we mapped the densities of redbay and sassafras from forest inventory data. Second, we used climate matching to delineate potential geographic limits for X. glabratus. Third, we used county infestation data to estimate the rate of spread and modeled spread through time, incorporating host density as a weighting factor. Our results suggest that (1) key areas with high concentrations of redbay have yet to be invaded, but some are immediately threatened; (2) climatic conditions may serve to constrain X. glabratus to the southeastern U.S. coastal region; and (3) if unchecked, X. glabratus may spread throughout the range of redbay in

Laurel wilt (Lw) disease is a fatal disease caused by the fungus Raffaelea lauricola. It is a vascular pathogen which clogs the xylem, blocking the flow of water and nutrients in infected plants, and it is considered as a major threat to the commercial avocado production in Florida. Many of these symptoms are similar to those that are caused by other diseases or factors, such as nutrient deficiency, and thus can be difficult to recognize in a proper time in order to eliminate the infected trees. The standard method for detection of Lw is the polymerase chain reaction technique which is destructive and time-consuming. Remote sensing using multi-spectral imagery has shown promising results for rapid detection of Lw in the field, but the challenge is to differentiate between Lw and trees with nutrient deficiency symptoms. A visible-near infrared (Vis-NIR) portable spectrophotometer was used to collect spectral data from LWD trees, as well as iron-(Fe) and nitrogen-(N) deficient trees and healthy (H) trees grown in greenhouses. Spectral data were collected during the early, and late stages of each symptom and averaged every 10 nm and 40 nm. Two classification methods: multilayer perceptron (MLP) neural network and decision tree (DT) were used to classify healthy, Lw, and stressed trees. MLP classification was more accurate than DT, reaching 99-100% classification accuracy. The best spectral bands for differentiating those classes, regardless to the stage, were mostly in red edge and near infrared. The results indicated that using the selected spectral bands it is possible to separate Lw from nutrient-deficient trees.

The redbay ambrosia beetle, Xyleborus glabratus, is an important pest of redbay (Persea borbonia) and swamp bay (P. palustris) trees in forests of the southeastern USA. It is also a threat to commercially grown avocado. The beetle is attracted to host wood volatiles, particularly sesquiterpenes. Contrary to other ambrosia beetles that attack stressed, possibly pathogen-infected, and dying trees, X. glabratus readily attacks healthy trees. To date little is known about the role of leaf volatiles in the host selection behavior and ecology of X. glabratus. To address this question, an olfactometer bioassay was developed to test the behavioral response of X. glabratus to plant leaf volatiles. We found that X. glabratus was attracted to the leaf odors of their hosts, redbay and swamp bay, with no attraction to a non-host tree tested (live oak, Quercus virginiana), which served as a negative control. Gas chromatography-mass spectrometry (GS/MS) analysis of leaves revealed the absence of sesquiterpenes known to be attractive to X. glabratus and present in host wood, suggesting that additional leaf-derived semiochemicals may serve as attractants for this beetle. An artificial blend of chemicals was developed based on GC/MS analyses of leaf volatiles and behavioral assays. This blend was attractive to X. glabratus at a level that rivaled currently used lures for practical monitoring of this pest. This synthetic redbay leaf blend also was tested in the field. Baited traps captured more X. glabratus than unbaited controls and equivalently to manuka oil lures. We hypothesize that leaf volatiles may be used by X. glabratus as an additional cue for host location.

Laurel wilt is a lethal disease of plants in the Lauraceae plant family, including avocado (Persea americana). This devastating disease has spread rapidly along the southeastern seaboard of the United States and has begun to affect commercial avocado production in Florida. The main objective of this study was to evaluate the potential to discriminate laurel wilt-affected avocado trees using aerial images taken with a modified camera during helicopter surveys at low-altitude in the commercial avocado production area. The ability to distinguish laurel wilt-affected trees from other factors that produce similar external symptoms was also studied. RmodGB digital values of healthy trees and laurel wilt-affected trees, as well as fruit stress and vines covering trees were used to calculate several vegetation indices (VIs), band ratios, and VI combinations. These indices were subjected to analysis of variance (ANOVA) and an M-statistic was performed in order to quantify the separability of those classes. Significant differences in spectral values among laurel wilt affected and healthy trees were observed in all vegetation indices calculated, although the best results were achieved with Excess Red (ExR), (Red–Green) and Combination 1 (COMB1) in all locations. B/G showed a very good potential for separate the other factors with symptoms similar to laurel wilt-affected trees, such as fruit stress and vines covering trees, from laurel wilt-affected trees. These consistent results prove the usefulness of using a modified camera (RmodGB) to discriminate laurel wilt-affected avocado trees from healthy trees, as well as from other factors that cause the same symptoms and suggest performing the classification in further research. According to our results, ExR and B/G should be utilized to develop an algorithm or decision rules to classify aerial images, since they showed the highest capacity to discriminate laurel wilt-affected trees. This methodology may allow the rapid detection of laurel wilt-affected trees using low altitude aerial images and be a valuable tool in mitigating this important threat to Florida avocado production.

Ambrosia-feeding scolytids in the Xyleborina are the most abundant exotic bark beetles in North America. Many new species discoveries and taxonomic changes have occurred since their last review in 1982. The need for a worldwide revision of this tribe hampers the ability to identify species. To remedy this situation, an illustrated key is constructed and Xyleborus glabratus Eichhoff, Xyleborus similis Ferrari, and Euwallacea fornicatus (Eichhoff), which are new to North America, are reported and diagnosed. In addition the key is presented in electronic format with additional illustration (http://scolytid.msu.edu) to increase worldwide availability and accommodate future taxonomic revision.

Ploetz, R. C., Schaffer, B., Vargas, A. I., Konkol, J. L., Salvatierra, J., and Wideman, R. 2015. Impact of laurel wilt, caused by Raffaelea lauricola ,o n leaf gas exchange and xylem sap flow in avocado, Persea americana. Phytopathology 105:433-440. Laurel wilt, caused by Raffaelea lauricola, is a destructive disease of avocado (Persea americana). The susceptibility of different cultivars and races was examined previously but more information is needed on how this host responds to the disease. In the present study, net CO2 assimilation (A), stomatal conductance of H2 O( gs), transpiration (E), water use efficiency (WUE), and xylem sap flow rates were assessed in cultivars that differed in susceptibility. After artificial inoculation with R. lauricola, there was a close relationship between symptom development and reductions in A, gs, E, WUE, and mean daily sap flow in the most susceptible cultivar, ‘Russell’, and significantly greater disease and lower A, gs, E ,W UE, and sap flow rates were usually detected after 15 days compared with the more tolerant ‘Brogdon’ and ‘Marcus Pumpkin’. Significant differences in preinoculation A, gs, E, and WUE were generally not detected among the cultivars but preinoculation sap flow rates were greater in Russell than in Brogdon and Marcus Pumpkin. Preinoculation sap flow rates and symptom severity for individual trees were correlated at the end of an experiment (r = 0.46), indicating that a plant’s susceptibility to laurel wilt was related to its ability to conduct water. The potential management of this disease with clonal rootstocks that reduce sap flow rates is discussed.

Redbay ambrosia beetle, Xyleborus glabratus Eichhoff, is an exotic wood borer and the primary vector of Raffaelea lauricola, a symbiotic fungus that causes laurel wilt. This lethal disease has decimated native redbay [Persea borbonia (L.) Sprengel] and swampbay [Persea palustris (Rafinesque) Sargent] throughout southeastern U.S. forests, and currently threatens avocado (Persea americana Miller) in Florida. To curtail the spread of laurel wilt, effective attractants are needed for early detection of the vector. Phoebe oil lures were the best known attractant for X. glabratus, but they are no longer available. The current detection system uses manuka oil lures, but previous research indicated that manuka lures have a short field life in Florida. Recently, cubeb oil was identified as a new attractant for X. glabratus, and cubeb bubble lures are now available commercially. This study compared trapping efficacy and field longevity of cubeb and manuka lures with phoebe lures that had been in storage since 2010 over a 12-wk period in south Florida. In addition, terpenoid emissions were quantified from cubeb and manuka lures aged outdoors for 12 wk. Captures were comparable with all three lures for 3 wk, but by 4 wk, captures with manuka were significantly less. Equivalent captures were obtained with cubeb and phoebe lures for 7 wk, but captures with cubeb were significantly greater from 8 to 12 wk. Our results indicate that cubeb bubble lures are the most effective tool currently available for detection of X. glabratus, with a field life of 3 months due to extended low release of attractive sesquiterpenes, primarily α-copaene and α-cubebene.

The genus Raffaelea was established in 1965 when the type species, Raffaelea ambrosia, a symbiont of Platypus ambrosia beetles was described. Since then, many additional ambrosia beetle symbionts have been added to the genus, including the important tree pathogens Raffaelea quercivora, Raffaelea quercus-mongolicae, and Raffaelea lauricola, causal agents of Japanese and Korean oak wilt and laurel wilt, respectively. The discovery of new and the dispersal of described species of Raffaelea to new areas, where they can become invasive, presents challenges for diagnosticians as well as plant protection and quarantine efforts. In this paper, we present the first comprehensive multigene phylogenetic analysis of Raffaelea. As it is currently defined, the genus was found to not be monophyletic. On the basis of this work, Raffaelea sensu stricto is defined and the affinities of undescribed isolates are considered.

The invasive redbay ambrosia beetle, Xyleborus glabratus, is the primary vector of Raffaelea lauricola, a symbiotic fungus and the etiologic agent of laurel wilt. This lethal disease has caused severe mortality of redbay (Persea borbonia) and swampbay (P. palustris) trees in the southeastern USA, threatens avocado (P. americana) production in Florida, and has potential to impact additional New World species. To date, all North American hosts of X. glabratus and suscepts of laurel wilt are members of the family Lauraceae. This comparative study combined field tests and laboratory bioassays to evaluate attraction and boring preferences of female X. glabratus using freshly-cut bolts from nine species of Lauraceae: avocado (one cultivar of each botanical race), redbay, swampbay, silkbay (Persea humilis), California bay laurel (Umbellularia californica), sassafras (Sassafras albidum), northern spicebush (Lindera benzoin), camphor tree (Cinnamomum camphora), and lancewood (Nectandra coriacea). In addition, volatile collections and gas chromatography-mass spectroscopy (GC-MS) were conducted to quantify terpenoid emissions from test bolts, and electroantennography (EAG) was performed to measure olfactory responses of X. glabratus to terpenoids identified by GC-MS. Significant differences were observed among treatments in both field and laboratory tests. Silkbay and camphor tree attracted the highest numbers of the beetle in the field, and lancewood and spicebush the lowest, whereas boring activity was greatest on silkbay, bay laurel, swampbay, and redbay, and lowest on lancewood, spicebush, and camphor tree. The Guatemalan cultivar of avocado was more attractive than those of the other races, but boring response among the three was equivalent. The results suggest that camphor tree may contain a chemical deterrent to boring, and that different cues are associated with host location and host acceptance. Emissions of α-cubebene, α-copaene, α-humulene, and calamenene were positively correlated with attraction, and EAG analyses confirmed chemoreception of terpenoids by antennal receptors of X. glabratus.

Laurel wilt is a vascular disease of plants in the Laurel family (Lauraceae) that has caused ex tensive mortality of redbay (Persea borbonia (L.) Spreng) trees in South Carolina, Georgia, and Florida. The disease is caused by a previously un described species of Raffaelea, a fungal symbiont of the non-native redbay ambrosia beetle, Xyle borus glabratus Eichhoff (Fraedrich et al. 2008). Xyleborus glabratus was initially detected in the US. near Savannah, GA in 2002 (Rabaglia et al. 2006). The beetle carries spores of the laurel wilt fungus in mandibular mycangia and inoculates the xylem of host trees by boring into the wood. In redbay, the fungus moves rapidly through the xy lem, plugging the flow of water and causing trees to die in a matter of weeks or a few months. Af fected trees are characterized by a dark discolor ation in the outer sapwood (Fraedrich et al. 2008). Laurel wilt continues to devastate populations of redbay in the southeastern coastal plain and the distribution of the disease has rapidly expanded (Johnson et al. 2008). In the summer and fall of 2006, 16 small avo cado (Persea americana var. americana Mill.) trees were planted on Ft. George Island, FL, a site with a high incidence of laurel wilt. By 12 Feb 2007, X glabratus and its associated Raffaelea sp. were obtained from two dying trees of the West In dian cultivar Donnie (A.E.M., J.E.P. & J.H.C., un published data). In September 2007, a large avo cado tree in a homeowner's yard in Jacksonville, FL also was discovered to be diseased with laurel wilt (Mayfield et al. 2008). In growth chamber ex periments, some avocado plants wilted after arti ficial inoculation with the laurel wilt pathogen (Fraedrich et al. 2008). Furthermore, avocado wood has been demonstrated to be attractive toX glabratus in field trapping trials (Hanula et al. in press). Concern exists that laurel wilt and X. gla bratus could negatively impact the commercial avocado industry in south Florida and beyond. There are 3 distinct races of avocado, West In dian (WI) (Persea americana var. americana Mill), Guatemalan (G) (P. americana var. guatemalensis Williams) and Mexican (M) [P. americana var drymifloia (Schlect. and Cham.)]. In Florida, West Indian and West Indian-Guatemalan hybrids are commercially grown; in California, mostly Guate malan-Mexican hybrids are grown. Two no-choice experiments were conducted to determine (1) whether Xyleborus glabratus would bore into healthy young avocado plants of various genetic backgrounds, and (2) whether these bee tles could transmit the laurel wilt pathogen (Raf faelea sp.) into those plants. Stem sections (ap prox. 30 cm long and 10 cm in diameter) from wilted redbay trees infested with X. glabratus were collected from Jennings State Forest, Clay County, FL in early May 2007 and placed in rear ing containers at the Florida DACS Division of Plant Industry in Gainesville, FL. Emerging adult females were collected, sealed in Petri plates and transferred to a quarantine green house at the University of Florida, Indian River Research & Education Center in Fort Pierce, FL. Experimental plants were obtained in 3.8-L pots from a commercial nursery near Homestead, FL and ranged from 1.2-4.4 cm in basal diameter and 43.0-94.0 cm in height. Experiment 1 included 4 plants from each of 4 avocado cultivars represent ing different genetic backgrounds: 'Hass' (G-M hybrid), 'Simmonds' (WI), 'Monroe' (G-WI hybrid), and Winter Mexican' (M). These particular culti vars were of interest because 'Hass' is a widely grown commercial cultivar in California, 'Sim monds' and 'Monroe' are popular Florida culti vars, and 'Winter Mexican' is a pure Mexican race cultivar. Within each cultivar, 2 plants were ran

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 efficacy of manuka oil lures and insufficient availability of phoebe oil prompted us to investigate the reasons behind changes in manuka oil lure efficacy 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 8-9 wk when released from bubble lures.

Marc A. Hughes, Department of Plant Pathology, University of Florida, Gainesville, FL 32611; Gurpreet Brar, Department of Entomology and Nematology, University of Florida, Gainesville, FL 32611; Randy C. Ploetz, Department of Plant Pathology, Tropical Research and Education Center, University of Florida, Homestead, FL 33031; and Jason A. Smith, School of Forest Resources and Conservation, University of Florida, Gainesville, FL 32611

Summary Laurel wilt is a devastating invasive disease of members of the Lauraceae plant family. It is caused by the fungus Raffaelea lauricola, which is a nutritional symbiont of its ambrosia beetle vector, Xyleborus glabratus. In the United States, six Raffaelea spp., in addition to R. lauricola, have been recovered from mycangia of X. glabratus. We compared the response of two laurel wilt suspects, swamp bay (Persea palustris) and redbay (Persea borbonia), to five of these species, another undescribed Raffaelea sp., and R. lauricola. Six weeks after inoculation, only R. lauricola caused significantly greater symptoms than water inoculations. The fungi varied in their ability to move systemically and be recovered from the host at the end of the experiment. Stem hydraulic conductivity was decreased by R. lauricola, but none of the other taxa. Although the roles these fungi play in the life cycle of X. glabratus are not known, they do not appear to be pathogens on these host tree species.

La detección de una nueva enfermedad en el Continente Americano concretamente en el sureste de los Estados Unidos de América (EUA), se ha denominado como “Laurel wilt”. Es ocasionada por el hongo Raffaelea lauricola (T.C. Harr., Aghayeva, y Fraedrich.), introducida a EUA en madera sólida de embalaje, junto con su vector natural Xyleborus glabratus [Eichhoff.] (Curculionidae: Scolytinae: Scolytini), ambos plagas nativas del sureste asiático en árboles de la familia Lauraceae. En los EUA este complejo plaga-patógeno, a partir de su introducción, ha ocasionado cuantiosas pérdidas ambientales y económicas superiores al 80 % en áreas naturales con laurel rojo (Persea borbonia L.). En el año 2010, se reportó la incidencia del complejo en el cultivo de aguacate (Persea americana Mill.) en el estado de Florida, con estimación de pérdidas económicas potenciales a esta industria. El objetivo del presente documento es proporcionar información respecto a la biología, desarrollo y distribución del complejo causal de la enfermedad, con la finalidad de determinar el estatus fitosanitario en México. Con el objeto de determinar el nivel de riesgo que implica la introducción, del complejo causal del Laurel wilt, se realizó el estudio del Análisis de Riesgo por Plaga (ARP) de acuerdo a lo establecido en el estándar internacional contenido en la Norma Internacional para Medidas Fitosanitarias (NIMF) No. 11, de la Convención Internacional de Protección Fitosanitaria (CIPF); como resultado se concluye que el complejo Xyleborus glabratus-Raffaelea lauricola son plagas cuarentenarias para México, con alto potencial de ocasionar importantes pérdidas económicas, por lo cual se determinan como de Riesgo alto. Se recomienda que el complejo sea incorporado al Programa Nacional de Plagas Bajo Vigilancia Epidemiológica, del Sistema Nacional de Vigilancia Fitosanitaria (SINAVEF), de la Dirección General de Sanidad Vegetal (DGSV) del SENASICA/SAGARPA como una plaga a vigilar. _______________ RISK ANALYSIS OF THE AMBROSIA BEETLE (Xyleborus glabratus Eichhoff.) AS A POTENTIAL PEST FOR AVOCADO CROP (Persea americana Mill.). ABSTRACT: The detection of a new disease in the Americas specifically in the southeastern United States of America (USA), has been called "Laurel wilt." It is caused by the fungus Raffaelea lauricola (TC Harr., Aghayeva, and Fraedrich.), Introduced to the United States in solid wood packaging, together with the natural vector Xyleborus glabratus [Eichhoff.] (Curculionidae: Scolytinae: Scolytini), both native pests in trees in Southeast Asia Lauraceae family. In the U.S. this pest-pathogen complex, since its introduction, has caused environmental and economic losses of over 80% in natural areas with red bay (Persea borbonia L.). In 2010, the incidence was reported in growing complex of avocado (Persea americana Mill) in the state of Florida, with estimated potential economic losses to the industry. The aim of this paper is to provide information regarding the biology, development and distribution of the causative complex, in order to determine the phytosanitary status in Mexico. In order to determine the level of risk involved in the introduction, the complex causal Laurel wilt, the study was conducted by the Pest Risk Analysis (PRA) in accordance with the provisions of the international standard contained in the International Standard for Measures phytosanitary Measures (ISPM) No. 11 of the International Plant Protection Convention (IPPC), as a result it is concluded that the complex Xyleborus glabratus-Raffaelea lauricola are quarantined for Mexico, with high potential to cause significant economic losses, which are determined as high risk. It is recommended that the complex is incorporated into the National Pest Under Epidemiological Surveillance, National Surveillance System Plant (SINAVEF) of the Plant Health Directorate (DGSV) SENASICA / SAGARPA as a pest to watch.

The redbay ambrosia beetle, Xyleborus glabratus Eichhoff, is a non-native invasive pest and vector of the fungus that causes laurel wilt disease in certain trees of the family Lauraceae. This study assessed the relative attractiveness and suitability of cut bolts of several tree species to X. glabratus. In 2009, female X. glabratus were equally attracted to traps baited with swampbay (Persea palustris (Rafinesque) Sargent) and camphortree (Cinnamomum camphora (L.) J. Presl), which were more attractive than avocado (Persea americana Miller), lancewood (Ocotea coriacea (Swartz) Britton), and sweetbay (Magnolia virginiana L.). These species were more attractive than loblolly bay (Gordonia lasianthus (L.) J. Ellis). X. glabratus entrance hole density and emergence from caged bolts were highest on swampbay and camphortree. In 2010, swampbay was significantly more attractive to X. glabratus than sassafras (Sassafras albidum (Nuttall) Nees), yellow poplar (Liriodendron tulipifera L.), and eastern redbud (Cercis canadensis L.). Sassafras bolts end sealed with a liquid wax-and-water emulsion were more attractive to X. glabratus than end-sealed bolts of yellow poplar and redbud. Relative to unsealed bolts, end seal decreased X. glabratus entrance hole density on swampbay and decreased granulate ambrosia beetle (Xylosandrus crassiusculus (Motschulsky)) trap catch, entrance hole density, and adult emergence from swampbay. X. crassiusculus was not attracted to sassafras, yellow poplar, and redbud and was not more attracted to manuka oil than to unbaited traps. Sassafras was more attractive to X. glabratus than previously reported and supported reproducing populations of the insect. End sealing bolts with a wax-and-water emulsion may not be optimal for attracting and rearing ambrosia beetles in small logs.

Invasive fungus-growing ambrosia beetles are an emerging threat to forest ecosystems and fruit industries, but management tools are lacking. Here we explored the potential of beetle symbionts–ambrosia fungi–as a source of attractants. Our focus was the redbay ambrosia beetle, Xyleborus glabratus, and its symbiotic fungus, Raffaelea lauricola, which are devastating lauraceous hosts in the southeastern United States. We also tested three additional co-occurring beetle species and their symbionts. Each beetle species was consistently attracted to the odors of its symbiotic fungal species, occasionally also to symbionts of other species, but never to non-symbiotic Trichoderma. We further confirmed attraction to ethanol (positive control) in some species. Thus, ambrosia fungi produce volatiles attractive to their vector beetles, which may have potential as novel lures for ambrosia beetle management.