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The whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) is a notorious agricultural pest and the effective vector of many plant viruses worldwide. Cucurbit chlorotic yellows virus (CCYV), exclusively transmitted by B. tabaci in a semipersistent manner, is a serious causal agent in cucurbit crops in many countries. Plant viruses can manipulate the behaviors of insect vectors to promote the spread of themselves, but underlying mechanisms are remaining unclear.In this study, our observations indicated that B. tabaci, when carrying CCYV, oriented more actively to the host plant cucumber. Transcriptome analysis and quantitative polymerase chain reaction with reverse transcription analysis showed that the odorant-binding protein 5 (OBP5) was upregulated with viral acquisition. Sequence and phylogenetic analysis showed that BtabOBP5 was highly homologous with nine OBPs from other hemipteran insects. In addition, OBP5-silenced whiteflies significantly altered their orientation behavior towards cucumber plants and towards some typical volatile organic compounds released from cucumbers.This study described a novel mechanism by which the olfactory system of vector insects could be regulated by a semipersistent plant virus, thereby affecting insect olfactory behavior and relationship with host plants. These results provided a basis for developing potential olfaction-based pest management strategies in the future. © 2022 The Authors. Pest Management Science published by John WileySons Ltd on behalf of Society of Chemical Industry.

Tea is an important global beverage crop and is largely clonally propagated. Despite previous studies on the species, its genetic and evolutionary history deserves further research. Here, we present a haplotype-resolved assembly of an Oolong tea cultivar, Tieguanyin. Analysis of allele-specific expression suggests a potential mechanism in response to mutation load during long-term clonal propagation. Population genomic analysis using 190 Camellia accessions uncovered independent evolutionary histories and parallel domestication in two widely cultivated varieties, var. sinensis and var. assamica. It also revealed extensive intra- and interspecific introgressions contributing to genetic diversity in modern cultivars. Strong signatures of selection were associated with biosynthetic and metabolic pathways that contribute to flavor characteristics as well as genes likely involved in the Green Revolution in the tea industry. Our results offer genetic and molecular insights into the evolutionary history of Camellia sinensis and provide genomic resources to further facilitate gene editing to enhance desirable traits in tea crops., Haplotype-resolved genome assembly of an Oolong tea cultivar Tieguanyin and population genomic analyses of 190 Camellia accessions provide insights into the evolutionary history of the tea plant Camellia sinensis.

Many studies on the inelastic response spectra have mainly focused on structures with the conventional hysteretic behavior. However, for self-centering structures with the flag-shaped (FS) hysteretic behavior, the corresponding study is limited. The primary aim of this study is to investigate the inelastic response spectra of self-centering structures with FS hysteretic behavior subjected to the near-fault pulse-type ground motion. To this end, the smooth FS hysteretic model based on Bouc–Wen model is developed, and the characteristics of pulse-type ground motions are described in detail. It is found that the general features of inelastic response spectra of the FS model are sensitive to the acceleration-, velocity-, and displacement-sensitive spectral regions of the ground motion. The inelastic displacement, velocity, acceleration, and ductility factor spectra of the FS hysteretic model for pulse-type ground motions are much larger than those for ordinary ground motions, while the residual displacement spectra under the two types of ground motions are both very small due to its self-centering capacity. Moreover, the inelastic response spectra are affected by the ground motion characteristics and structural hysteresis behavior, especially the large pulse period and peak ground velocity (PGV) significantly increase the inelastic displacement, velocity, and acceleration spectra.

Increased insecticide resistance among insect vectors and arboviruses results in significant economic losses to agricultural production and poses a continuous threat to human health. To date, many studies have been conducted on how virus-infected host plants indirectly and plant virus directly change the physiological characteristics of insect vectors. However, the relationship between the insecticide resistance of the insect vector and the virulence of the viral pathogen has not received sufficient attention. Here, we investigated the effect of Cucurbit chlorotic yellows virus (CCYV), a plant virus transmitted by whitefly (Bemisia tabaci) in a semi-persistent manner, on the tolerance of B. tabaci to the neonicotinoid imidacloprid. We found CCYV enhanced the tolerance of B. tabaci to imidacloprid. The CYP6CM1 gene was significantly up-regulated in viruliferous susceptible B. tabaci compared with non-viruliferous B. tabaci after an acquisition access period of 10 d, including its upstream regulators. Silencing the CYP6CM1 gene by RNA interference reduced the ability of B. tabaci to acquire CCYV compared with the control. Additionally, imidacloprid-resistant B. tabaci outperformed sensitive adults in terms of virus transmission ability. These results suggest that CCYV enhances the ability of imidacloprid-sensitive B. tabaci to resist adverse external factors (insecticides). In turn, B. tabaci resistance affects virus transmission. Thus, to a certain extent, the plant virus and insect vector establish a mutually beneficial relationship that facilitates virus transmission.

The safety of lake ecosystems on the Qinghai-Tibet Plateau (QTP) has attracted increasing attention, owing to its unique location and ecological vulnerability. Previous studies have shown that the aquatic systems on the QTP have been polluted to varying degrees by trace elements. However, little is known of the distribution and sources of trace elements in lakes in the northeast QTP. Here, 57 sediment samples were collected from six lakes (Dasugan Lake, Xiaoqaidam Lake, Kreuk Lake, Toson Lake, Gahai Lake and Xiligou Lake) in the Qaidam Basin, northeast QTP, and the trace elements (V, Cr, Ni, Cu, Zn, As, Ba, Tl, Cd, Pb, and U) were analyzed. The results indicated that Ba, Zn, V, and Cr had a higher content and a wider distribution relative to the other tested elements. Correlation coefficient matrix results showed that the trace elements in the study area were strongly correlated, revealing their source of similarity. Self-organizing maps (SOM, an artificial neural network algorithm) results indicated that the degree of pollution in Xiaoqaidam Lake was the highest, and that of Dasugan Lake was the lowest. Furthermore, all sampling points were clustered into four categories through K-means clustering. The positive matrix factorization (PMF) results indicated that atmospheric deposition and anthropogenic inputs were the main trace elements sources in these lakes, followed by traffic emission and geological sources. Collectively, trace elements of six lakes in Qinghai-Tibet Plateau presented high-content and pollution characteristics. This research provides a scientific basis for better water environment management and ecological protection on the QTP.

Background Plant metabolites play vital roles in regulating the behavior of herbivore insects. Virus infection can universally alter plant metabolites to manipulate the orientation and feeding behaviors of insect vector, to favor the transmission of virus. Thus, determining the differentially accumulated metabolites of plant upon virus infection could provide insights into understanding how the triple interactions among plant, virus and insect vector happens. Our previous studies have found that vector whitefly Bemisia tabaci (Gennadius, Hemiptera: Aleyrodidae) showed different orientation behavior and performance on CCYV-infected and healthy cucumber plants. Cucurbit chlorotic yellows virus (CCYV) is exclusively transmitted by B. tabaci in a semi-persistent mode. In this study, we take the CCYV, B. tabaci and cucumber as a research system to explore the functions of phyto-metabolites in the triple interactions. Results A total of 612 metabolites changed upon CCYV infection were monitored. Metabolites mainly enriched in flavonoids, lipids, nucleotides and their derivatives. At 7 days post CCYV inoculation (dpi), the contents of lipids, terpenoids and flavonoids remarkably decreased, while amino acids, nucleotides and their derivatives notably up-accumulated. At 15 dpi, the accumulation of flavonoids were still significantly reduced upon CCYV infection, while lipids, amino acids, nucleotides and derivatives were remarkably enhanced. Most of significantly increased metabolites were lipids (lysophosphatidylethanolamine, LPE; lysophosphatidylcholine, LPC and their isomers). Also, the number of significantly changed metabolites increased with the infection period. However, only a few organic acids and phenolic acids showed difference between CCYV-infected and healthy cucumber plants. Conclusions CCYV infection repressed the defensive flavonoids, terpeneoids metabolism but triggered the lipids, amino acids and nucleotides metabolism with the inoculation period. This result suggests that CCYV-infection makes cucumber plants more susceptible for whiteflies attack and CCYV infection. The reduction of defensive comounds and the increase of amino acids may be partially responsible for enhancing feeding preference of whiteflies to CCYV-infected hosts. CCYV may hijacked lipid metabolism for virus replication and assembly.

Plant viruses can change the phenotypes and defense pathways of the host plants and the performance of their vectors to facilitate their transmission. Cucurbit chlorotic yellows virus (CCYV) (Crinivirus), a newly reported virus occurring on cucurbit plants and many other plant species, is transmitted specifically by Bemisia tabaci MEAM1 (B biotype) and MED (Q biotype) cryptic species in a semipersistent manner. This study evaluated the impacts of CCYV on B. tabaci to better understand the plant-virus-vector interactions. By using CCYV-B. tabaci MED-cucumber as the model, we investigated whether or how a semipersistent plant virus impacts the biology of its whitefly vector. CCYV mRNAs were detectable in nymphs from first to fourth instars and adults of B. tabaci with different titers. Nymph instar durations and adult longevity of female whiteflies greatly extended on CCYV-infected plants, but nymph instar durations and adult longevity of male whiteflies were not significantly influenced. In addition, the body length and oviposition increased in adults feeding on CCYV-infected plants, but the hatching rates of eggs and survival rates of different stages were not affected. Most interestingly, the sex ratio (male:female) significantly reduced to 0.5:1 in whitefly populations on CCYV-infected plants, while the ratio remained about 1:1 on healthy plants. These results indicated that CCYV can significantly impact the biological characteristics of its vector B. tabaci. It is speculated that CCYV and B. tabaci have established a typical mutualist relationship mediated by host plants.

Cucurbit chlorotic yellows virus (CCYV) has caused serious damage to melon crops in many countries in recent years. It is exclusively transmitted by the notorious pest Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) in a semi-persistent manner. Previous studies have shown that both persistently and non-persistently transmitted viruses can manipulate orientation and performance of vector insects through changing host phenotype to facilitate virus spread. However, as a semi-persistently transmitted virus, how CCYV affect vector B. tabaci in locating host plants by altering physiological traits of host plants is still unknown. In this study, we investigated B. tabaci visual and olfactory preference between healthy and CCYV-infected host plant Cucumis sativus. Volatile profiles of healthy and CCYV-infected C. sativus plants were analyzed by using gas chromatography-mass spectrometry (GC-MS). Initially, it was found that vector insects preferred to settle down CCYV-infected Cucumis sativus seedlings in free choice. The concentrations of total volatiles and terpenes in cucumber plants were notably decreased after CCYV infection, and especially, the concentrations of α-pinene, β-ocimene, α-farnesene, and nonanal, responsible for olfactory attraction of B. tabaci, dramatically reduced in CCYV-infected plants. Subsequently, we investigated the visual preference of B. tabaci to CCYV-infected and healthy host, and found that B. tabaci adults showed significant preference to CCYV-infected host. CCYV induced yellowing symptoms in host leaves may explain the visual preference of B. tabaci adults to infected hosts. This study indicated that visual cues could play a vital role in vector insects locating virus-infected host plants.

It is known that plant viruses, to facilitate their transmission, can change the phenotypes and defense pathways of the host plants and the performance of their vectors. Cucurbit chlorotic yellows virus (CCYV), a newly reported virus occurring on cucurbit plants and many other plant species, is transmitted specifically by Middle East-Minor Asia 1 (B biotype) and Mediterranean (Q biotype) cryptic species of whitefly, Bemisia tabaci (Gennadius), in a semipersistent manner. This study evaluated the direct and indirect effects of CCYV on B. tabaci biology to better understand the plant-virus-vector interaction. By using CCYV-B. tabaci-cucumber as the model, we investigated whether or how a semipersistent plant virus impacts the biology of its whitefly vectors. CCYV mRNA were detectable in nymphs from 1st to 4th instars and adults of B. tabaci with different titers. Female nymph duration and female adult longevity greatly extended on CCYV-infected plants, but male nymph duration and male adult longevity were not significantly influenced. In addition, on CCYV-infected plants, the body length and oviposition of adult B. tabaci increased, but the hatching rates of eggs and survival rates of different stages were not affected. Most interestingly, the sex ratio (male:female) significantly reduced to 0.506:1 in whitefly populations on CCYV-infected plants, while the ratio remained about 0.979:1 on healthy plants. These results indicated that CCYV can significantly impact the biological characteristics of its vector B. tabaci through the host plants. It is speculated that CCYV and B. tabaci have established a typical mutualist relationship mediated by host plants.

Simple Summary Leafhoppers are serious insect pests in agriculture across the world. Both nymphs and adults suck the sap of plant shoots and leaves with their piercing–sucking mouthparts causing damage called “hopperburn”. The tea green leafhopper, Empoasca onukii, is one of most damaging pests in tea plantations in Asia. In China, yellow sticky cards and light traps are increasingly used to control leafhoppers in tea plantations, especially the tea green leafhopper. Visually, several leafhoppers appear to be captured and killed, however, the real control efficiency and the damage to natural enemies remains unclear. In our study, a 16-week open field experiment with daily weather monitoring was designed to test the responses of tea green leafhopper, parasitoids and spiders to yellow sticky cards and light traps (cover with sticky cards) that used different light colours. An exclosure experiment was also designed to further test the influence of the three light systems (without sticky card) on the same groups of species. The results suggested that light, especially green and white, can be useful as a way to control leafhopper populations without affecting parasitoids and spiders too much. Abstract In Chinese tea plantations, yellow sticky cards and light traps are increasingly used to control insect pests, especially the tea green leafhopper Empoasca onukii. In this study, a 16-week open-field experiment with daily weather monitoring was designed to test the responses of tea green leafhopper, parasitoids and spiders to yellow sticky cards and three light traps with different wavelengths (covered with sticky cards). An exclosure experiment was also designed to further test the influence of the three light systems (without sticky card) on the same species. The results showed that all three light emitting diode (LED) light traps (white, green and yellow) and yellow sticky cards attracted many more E. onukii male adults than females during the course of the open field experiment, with less than 25% of trapped adults being females. Parasitoids and spiders were also attracted by these systems. Weather variables, especially rainfall, influenced the trapping efficiency. In the exclosure experiment, the population of leafhoppers in the yellow sticky card treatment did not decline significantly, but the number of spiders significantly decreased. The green and white light treatments without sticky cards showed a significant control of E. onukii and no obvious harm to spiders. These results suggest that yellow sticky cards and light traps have limited capacity to control tea green leafhoppers. However, light, especially green light, may be a promising population control measure for tea green leafhoppers, not as killing agents in the traps, but rather as a behavioral control system.

Background: It is known that plant viruses, to facilitate their transmission, can change the phenotypes and defense pathways of the host plants and thereby the performance of their vectors. Cucurbit chlorotic yellows virus (CCYV), a newly reported virus occurring on cucurbit plants and many other plant species, is transmitted specifically by B and Q biotypes of tobacco whitefly, Bemisia tabaci (Gennadius), in a semipersistent manner. This study evaluated the direct and indirect effects of CCYV on B. tabaci performance to better understand the plant-virus-vector interaction in terms of its impacts on the biological characteristics of its vector.Methods: In this study, by using CCYV-B. tabaci-cucumber as the model, we investigated whether or how a semipersistent plant virus impacts the biology of its whitefly vectors directly and/or indirectly. Virion titer, body size, life table parameters, survival rate of nymphs and adults, reproduction capacity of both adult sexes as well as sex ratio were compared between whiteflies on CCYV-infected plants and ones on healthy plants. Results: CCYV virions were detectable in nymphs from 1st to 4th instar and adults of B. tabaci with different titers. Female nymph duration and female adult longevity greatly extended on CCYV-infected plants, but male nymph duration and male adult longevity were not significantly influenced. In addition, on CCYV-infected plants, the body length and oviposition of adult B. tabaci increased, but the egg hatching rate and survival rate of different stages of the whiteflies were not affected. Most interestingly, the sex ratio (female:male) significantly increased up to 66.40% in whitefly populations on CCYV-infected plants, while the female ratio remained about 50.53% on healthy plants. Conclusions: These results indicated that CCYV can significantly impact the biological characteristics of its vector B. tabaci through the host plants. It is speculated that CCYV and B. tabaci have established a typical mutualist relationship mediated by host plants.

Tea plantations have used many synthetic chemicals to ensure performance and control of pests. This has led to increased contamination of soils and reduced tea growth. We assessed the levels of heavy metals, including Cd, Cr, Pb, Cu, Ni, Zn, Hg, As, and pesticide residues, such as HCHs, biphenyl chrysanthemum ester, methamidophos, imidacloprid, permethrin, in the soil of tea plantations of Taiwan, Tibet, Guangdong, and Fujian. The Potential Ecological Risk Index and the Nemerow comprehensive pollution index were used to analyze the data. The results showed that risk indices in Tibet, Guangdong and Fuzhou were considered as moderate ecological harm level. Ecological risk assessment index of Anxi organic and Anxi conventional tea gardens suggested a &ldquo, low&rdquo, risk level. The Nemerow comprehensive pollution indices for soil pesticide residues in the tea plantations of Taiwan, Tibet, Anxi organic and Anxi conventional were considered mild. Guangdong and Fuzhou had values suggesting &ldquo, slight pollution&rdquo, levels. According to National Soil Environmental Quality Standard (GB15618-1995), soil in tea plantations in Taiwan, Tibet, and Anxi conventional matched the national first grade of soil quality and those from Guangdong, Fuzhou, and Anxi organic tea garden matched the national second grade.

Rocking bent is a potential alternative for seismic resistant and post-earthquake resilience of bridges. In order to study the seismic response of rocking double-column bridge bents with external hysteretic dissipaters, this paper developed an analytical model considering the impact and dissipater fracture. The benefits of dissipaters for rocking bridge bents were validated compared with the free-rocking bent. The influence of the hysteretic dissipater parameters on the seismic response of rocking bridge bent were also analyzed. The analysis considers far-field and near-field earthquake records. The study results show that the external hysteretic dissipaters have attractive benefit on the seismic response and stability of rocking double-column bridge bents. The dissipater fracture and overturning are sensitive to the distinctive pulses of near-field records, which is crucial from the design point of view.

The finite element software ABAQUS is used to analyze the influence of hinge joint crack on transverse load distribution of prefabricated concrete hollow core slab bridge, including single-...