Native to Asia, the spotted lanternfly, Lycorma delicatula (White), is an emerging pest of many commercially important plants in Korea, Japan, and the United States. Determining its potential ...distribution is important for proactive measures to protect commercially important commodities. The objective of this study was to assess the establishment risk of L. delicatula globally and in the United States using the ecological niche model MAXENT, with a focus on Washington State (WA), where large fruit industries exist.The MAXENT model predicted highly suitable areas for L. delicatula in Asia, Oceania, South America, North America, Africa, and Europe, but also predicted that tropical habitats are not suitable for its establishment, contrary to published information. Within the United States, the MAXENT model predicted that L. delicatula can establish in most of New England and the mid-Atlantic states, the central United States and the Pacific Coast states, including WA. If introduced, L. delicatula is likely to establish in fruit-growing regions of the Pacific Northwest. The most important environmental variables for predicting the potential distribution of L. delicatula were mean temperature of driest quarter, elevation, degree-days with a lower developmental threshold value of 11°C, isothermality, and precipitation of coldest quarter. Results of this study can be used by regulatory agencies to guide L. delicatula surveys and prioritize management interventions for this pest.
The invasive spotted lanternfly, Lycorma delicatula, (White Hemiptera: Fulgoridae) continues to spread throughout the Eastern United States. This species exhibits a broad host range, with tree of ...heaven, Ailanthus altissima (Mill.) Swingle, commonly referred to as the preferred host. Here, we evaluated 2-wk survivorship of early nymphal instars, late nymphal instars, and adult L. delicatula on single diets of ten wild and cultivated hosts: tree of heaven; apple, Malus domestica; peach, Prunus persica; black cherry, P. serotina Ehrh; black locust, Robinia pseudoacacia L.; black walnut, Juglans nigra L.; common hackberry Celtis occidentalis L.; mulberry Morus alba L.; sugar maple Acer saccharum Marshall; white oak, Quercus alba L.. Among them, early and late instars had significantly greater survivorship on tree of heaven and black walnut and adults had greatest survivorship on tree of heaven. Additionally, we evaluated development and survivorship of L. delicatula from newly hatched nymphs to adulthood on single diets of tree of heaven, black walnut, grapevine, apple, and peach, and mixed diets of tree of heaven plus one other host. Single host diets that supported L. delicatula development to adulthood were tree of heaven and black walnut. Interestingly, mixed diets also supported development, and reduced development time to adults by up to 12% compared with the single tree of heaven diet. Our results suggest that within agroecosystems and across landscapes, L. delicatula can develop on single hosts such as tree of heaven, but also on multiple host plants, yielding adults earlier in the growing season.
Lycorma delicatula White (Hemiptera: Fulgoridae) is an invasive phloem feeder with a broad host range that includes both hardwood trees and cultivated temperate fruit crops. Here, we evaluated ...acceptability of wild hosts, A. altissima and Juglans nigra L. (Fagales: Juglandaceae) and cultivated hosts Vitis vinifera, Malus domestica (Rosales: Rosaceae), and Prunus persica L. Batsch (Rosales: Rosaceae) to L. delicatula under field conditions. Fluorescent-marked early instar nymphs, late instar nymphs, or adult L. delicatula were released at the base of single potted host plants and the number of individuals retained was recorded over 24 h. Paired choice trials with A. altissima and another host plant were conducted. Individuals retained on or moving between plants were recorded over 24 h. Sentinel A. altissima, J. nigra, V. vinifera, M. domestica, and P. persica potted plants were deployed at 5 sites and the number of L. delicatula present on each plant was recorded weekly. In single and paired host trials, early instars and adults were generally retained in higher numbers on A. altissima and V. vinifera, and late instars were retained on A. altissima and J. nigra. Significantly more L. delicatula were present on sentinel A. altissima compared with other host plants, except J. nigra during the period when late instars were the most prevalent lifestage in the field. These results indicate that wild hosts such as A. altissima and J. nigra are likely supporting establishment of L. delicatula populations, and that presence of cultivated V. vinifera may contribute to population establishment and growth.
•Genetic factors did not influence the Verticillium dahliae-Ailanthus pathosystem.•Different Ailanthus provenances are not related to specific ecotypes.•Citizen science: a fine approach to fill data ...gaps in invasive species distribution.•Citizen science supports the collection in Ailanthus samples across/outside Italy.
Ailanthus altissima (Mill.) Swingle is considered one of the worst invasive alien plant species (IAPS) in Europe, able to cause several disturbances to ecosystems and economic issues. To date, the control methods applied are often ineffective, restricted or under assessment by the scientific community, as in the case of Verticillium dahliae (a promising biological control agent to counteract this species). Citizen science initiatives aim to involve the public in the research process to generate genuine outcomes and, in the case of invasive species, represent a valuable additional tool in their earlier detection, monitoring and management. Here, seventy-two citizens were recruited to recognize and record A. altissima across and outside Italy, as well as to collect leaf and seed samples to allow professional scientists to perform the molecular characterization of the Italian (and more) gene pool and, subsequently, test the susceptibility of these provenances to V. dahliae. The collected material matched the identification for the 97% of the cases, and included 129 accessions divided in four genetic groups (with a high percentage of variability, as typically observed for other IAPS subjected to frequent movements and the constant supply of new propagules). Verticillium dahliae inoculation of plants from different provenances selected for each genetic group, revealed a very high mortality (≥93%) independently to the origin area. These outcomes confirm the high susceptibility of A. altissima to the fungal pathogen, and lead to speculate that V. dahliae seems to have no limits in counteracting Ailanthus populations, at least at the Italian level.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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•The impact of V.nonalfalfae isolate Vert56 on non-target agricultural crops was tested.•Spinach was similarly affected by Vert56 as the target species A. altissima.•Other susceptible ...but less affected species were cucumber, petunia and tomato.•The use of Vert56 as biocontrol agent requires safety precautions in some crops.•Inoculation by root dipping was equally successful compared to stem inoculations.
Tree of Heaven (Ailanthus altissima), a tree species native to China, was introduced into Europe as an ornamental plant about 250 years ago. It is known for its invasive spread with negative impacts on natural ecosystems as well as human infrastructure. Its control is inevitable in some areas, e.g. transportation corridors, for safety reasons. Furthermore, management actions are mandatory according to EU legislation, but common strategies are time-consuming, costly, only moderately effective and, in case of herbicide treatments, controversially discussed due to environmental issues. Isolate Vert56 of the vascular wilt fungus Verticillium nonalfalfae has been proven in previous studies to be highly adapted and highly virulent to Ailanthus, while inoculation of potentially susceptible tree species with this isolate showed no evidence of negative non-target effects.
This study focused on non-target effects of isolate Vert56 on agricultural crops known to be generally susceptible to Verticillium spp. In a greenhouse experiment, seedlings of seven different species (including Ailanthus as a positive control) were artificially inoculated via root dipping or, in the case of seedlings of two potato varieties, by direct addition of the inoculum into the pot.
All plants were subsequently assessed for symptoms during the following two months. After assessment, plants were harvested to determine dry biomass. Likewise, tissue samples were used for re-isolation of the pathogen. Besides morphological identification, 25% of the obtained fungal cultures were analyzed with species-specific primers. The pathogen was consistently detected in all species. In addition to Ailanthus, three species (Cucumis sativus, Petunia × hybrid, Spinacia oleracea) developed severe wilting symptoms and showed a decrease in biomass compared to control plants. One species, Solanum lycopersicum, displayed a decrease in biomass although only slight wilting symptoms were observed within a short period after inoculation. Humulus lupulus, Medicago sativa and Solanum tuberosum were not negatively affected by V.nonalfalfae isolate Vert56. These results indicate that safety precautions must be taken, or at least considered, when growing susceptible plants in the vicinity of Vert56-treated Ailanthus, but they also show that this biological control agent is suitable for the treatment of Ailanthus on/next to agricultural land.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The tree of heaven,
Ailanthus altissima
(
MILL
.)
SWINGLE
, is a globally invasive plant known to secrete allelopathic metabolites called quassinoids. Quassinoids are highly modified triterpenoids. ...So far, nothing has been known about the biochemical basis of quassinoid biosynthesis. Here, based on transcriptome and metabolome data of
Ailanthus altissima
, we present the first three steps of quassinoid biosynthesis, which are catalysed by an oxidosqualene cyclase and two cytochrome P450 monooxygenases, resulting in the formation of the protolimonoid melianol. Strikingly, these steps are identical to the first steps of the biosynthesis of limonoids, structurally different triterpenoids from sister plant families within the same order Sapindales. Our results are therefore not only important to fully understand the biosynthesis of complex triterpenoids in plants, but also confirm the long-standing hypothesis that quassinoids and limonoids share an evolutionary origin. In addition, our transcriptome data for
Ailanthus altissima
will be beneficial to other researchers investigating the physiology and ecology of this invasive tree.
•Ultrasound affects cell wall composition.•Ultrasonic water treatment improves thermal stability of wood.•The ultrasonic-assisted effect is affected by the alkali concentration.
This study elucidates ...the mechanism of the influence of ultrasonic treatment on wood pyrolysis and the details of the thermal stability changes of samples treated with ultrasonic alkali are explained. Four groups of samples were designed to clarify this scientific question, including the control group, the ultrasonic water-treated group, the alkali-treated group and the ultrasonic alkali-treated group. The extractives contents (organic extractives and hot water extractives) were determined, the crystal region, the functional groups of chemical components, the distribution of chemical components, and the thermal stability of wood were investigated using X-ray diffraction, Fourier-transform infrared spectroscopy, confocal Raman microscopy, and thermogravimetric analysis, respectively. The results suggested that all the treatments reduced the extractives contents, increased the relative crystallinity, destroyed the structure of hemicellulose and lignin, and affected the thermal stability of wood, to different degrees. Ultrasonic time and alkali concentration were shown to be two important indexes. Ultrasound can enhance the treatment effects of low concentration alkali (0.1 %), but in a highly concentrated alkali environment, the auxiliary effect is not obvious. Ultrasonic treatment reduced the intensity of lignin in the whole cell wall region, while alkali treatment followed a more systematic process as the solvent permeated from the S layer to CCML. The initial degradation temperature T0 was not only related to the extractives content but also to the concentrations of hemicellulose and lignin in the sample. The hemicellulose degradation temperature T1 and cellulose degradation temperature T2 changed with changes in T0. A detailed understanding of the spatial and temporal variations of the major components in the rigid cell wall during the pretreatment process will help to develop more effective pretreatment strategies, which is crucial for the efficient optimization of the process.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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•Assessed regional biological control effectiveness against Ailanthus altissima.•Used two naturally occurring fungi, Verticillium nonalfalfae and V. dahliae.•V. nonalfalfae proved to ...be effective regardless of climate or stand differences.•Inoculation with both Verticillium spp. did not change V. nonalfalfae effectiveness.
Ailanthus altissima, perhaps the best-known example of an entrenched invasive weed tree in North America, was introduced to the Eastern U.S. roughly 240 years ago. The biological control of A. altissima has been a topic of interest since the discovery of a destructive naturally occurring Verticillium wilt disease of A. altissima in 2002. After nearly 20 years of research, an augmentative commercial release of this disease agent, Verticillium nonalfalfae, could be initiated in the near future. However, a few questions still remain: i) does the interaction of V. nonalfalfae with the less virulent V. dahliae inhibit the biological control effectiveness of V. nonalfalfae, and ii) do climate and A. altissima stand variables affect this biological control’s efficacy? To help answer these questions, a three-year field inoculation study including 3,245 A. altissima trees in 13 sites across four hardiness zones of Pennsylvania and Virginia, U.S. was implemented. Disease progressed and spread at similar rates in A. altissima trees co-inoculated with V. nonalfalfae and V. dahliae as those inoculated with V. nonalfalfae alone, with no indication of disease progression changing in co-inoculated trees. Verticillium dahliae alone resulted in lower levels of disease, and no disease spread. Similar results were seen in a supplemental greenhouse inoculation study. Despite slight regional variation of disease progression and spread correlated to climate or stand variables, V. nonalfalfae always caused severe disease and spread rapidly to other A. altissima trees through the forested plots. Our results support the use of V. nonalfalfae as a biological control agent throughout the mid-Atlantic region of the U.S. regardless of stand and climate variables, and including sites where trees are already infected with V. dahliae.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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