The whitefly, Bemisia tabaci, a globally significant pest transmitting over 200 plant viruses, has developed substantial resistance to insecticides, particularly neonicotinoids. Using near-isogenic lines, bulked segregant analysis (BSA), and genetic linkage analysis, we identified a major resistance locus on chromosome 6. The locus harbored dual mutations in the nicotinic acetylcholine receptor (nAChR) β1 subunit gene associated with high-level neonicotinoid resistance. Bioassays using gene-edited Drosophila melanogaster strains revealed that the R79E mutation conferred significant resistance to neonicotinoids. A field population carrying the R79E single mutation and exhibiting high-level resistance was subsequently identified using an optimized hybridization and backcrossing strategy combined with BSA. Furthermore, a six-year resistance monitoring program revealed that R79E is a major contributor to high-level neonicotinoid resistance in B. tabaci field populations. These findings improve our understanding of target-site resistance mechanism in agricultural pests and support the development of molecular tools for resistance monitoring and management.

The whitefly, Bemisia tabaci, is a major agricultural pest that has developed resistance to a broad range of insecticides. Despite the promising efficacy of cyantraniliprole (CYA) against B. tabaci, medium to high levels of resistance have emerged after prolonged field use. However, the mechanisms driving CYA resistance remain poorly understood. In this study, four B. tabaci strains exhibiting 24.9-fold to 28.9-fold resistance ratio to CYA were investigated. Synergist assays and enzyme activity measurements indicated cytochrome P450 enzymes contribute to this resistance. RNA sequencing and RT-qPCR analysis identified five P450 genes (CYP305H2, CYP6EM1, CYP3133D3, CYP3133D5, and CYP3133E2) as significantly overexpressed in resistant strains. Targeted silencing of these genes led to a 22.3% to 50.3% increase in CYA toxicity. The metabolic rates of these P450 enzymes against CYA were 2.5- to 6.0-fold higher than that in the control group within two hours. These results provide new insights into the molecular basis of CYA resistance in B. tabaci and highlight the pivotal role of cytochrome P450 enzymes in metabolic adaptation to diamide insecticides.

INTRODUCTION:UDP-glycosyltransferases (UGTs) are key Phase II detoxification enzymes in insects, playing a crucial role in resistance to a variety of insecticides, including diamides. Cyantraniliprole (CYA) is a systemic diamide insecticide with high toxicity against Bemisia tabaci, a major global agricultural pest transmitting over 200 plant viruses. While B. tabaci has developed medium-level resistance to CYA, the role of UGTs in this resistance remains poorly understood. OBJECTIVES:This study aimed to investigate the role of UGTs in B. tabaci resistance to CYA and further elucidate the underlying mechanisms. METHODS:Synergism bioassays and enzymatic activity analyses were conducted to assess the contribution of UGTs to CYA resistance. RNA sequencing and RT-qPCR were employed to identify differentially expressed BtUGT genes associated with resistance. The functions of UGTs and the UDP-glucose (UDPG) biosynthesis pathway in CYA resistance were confirmed through RNA interference and transgenic Drosophila melanogaster lines. The metabolites of CYA in the resistant strain were identified using LC-MS/MS. A cross-resistance study to chlorantraniliprole was performed to further confirm the role of UGTs in the diamide resistance of B. tabaci. RESULTS:Higher expression of UGTs represents a key metabolic resistance mechanism of B. tabaci to CYA. Specifically, overexpression of BtUGT352B2 and BtUGT352F1, along with the UDP-glucose biosynthesis pathway, contributed significantly to resistance. Four glycoside metabolites of CYA were putatively identified in resistant whiteflies. Significant cross-resistance to chlorantraniliprole confirmed that the UGT-mediated metabolism plays a crucial role in anthranilic diamide resistance in B. tabaci. CONCLUSION:This research advances our understanding of UGT-mediated insecticide resistance mechanisms and provides valuable insights for the development of more sustainable pest management strategies to combat pesticide resistance.

The sweet potato whitefly, Bemisia tabaci (Gennadius) is one of the most devastating pests, inflicting severe damage on a wide range of crops. The tetramic acid insecticides, spirotetramat and spiropidion, act as inhibitors of lipid biosynthesis by targeting acetyl-coenzyme A carboxylase (ACCase), disrupting fatty acid biosynthesis and energy metabolism. In the present study, a total of 47 field populations were collected across China in 2021 and 2022, and their susceptibilities to spirotetramat and spiropidion were determined in the laboratory. The results showed that in contrast to their toxicities against nymphs, spirotetramat and spiropidion exhibited minimal toxicity against B. tabaci adults. B. tabaci nymphs from field populations exhibited susceptibility or low resistance to spirotetramat, with LC50 values ranging from 2.85 to 13.58 mg L- 1 and resistance ratio (RR) from 1.7 to 8.2. There was a variation in the sensitivity of B. tabaci field populations towards spiropidion, with LC50 values ranging from 13.12 to 120.13 mg L- 1 and RR from 3.5 to 23.4. The baseline susceptibility of B. tabaci nymphs to spiropidion was determined to be 24.06 mg L-1, corresponding to the median lethal concentration (LC50) calculated from 43 field populations. Cross-resistance was observed between spirotetramat and spiropidion, as well as between cyantraniliprole and tetramic acid insecticides. However, no significant cross-resistance was found between neonicotinoids and tetramic acid insecticides. Collectively, these findings improve our knowledge on the toxicity of tetramic acid insecticides to B. tabaci populations in China and provide valuable information for their scientific application in the field.

The soybean cyst nematode (SCN, Heterodera glycines) relies on chemosensation for host localization and successful infection. Understanding the molecular basis of chemosensation is critical, as it determines the nematode's ability to locate and invade host roots. In the model nematode Caenorhabditis elegans, Transient Receptor Potential Vanilloid (TRPV) channels osm-9 and ocr-2 and the G-protein α subunit goa-1 mediate sensory perception and ion transport; however, their roles in SCN remain largely unexplored. Here, we cloned and characterized these three candidate genes, which showed predominant expression in the phasmids of preparasitic juveniles. RNA interference revealed distinct roles: Hg-goa-1 regulated locomotion, whereas Hg-osm-9 and Hg-ocr-2 controlled chemotaxis, particularly attraction under acidic and basic conditions. Silencing any gene reduced root penetration and reproduction, while gene interaction analyses suggested a cross-regulatory network. Collectively, these results identify the three genes as essential regulators of SCN chemosensation, locomotion, and parasitism, providing potential molecular targets for developing species-specific nematicides.

The sweet potato whitefly, Bemisia tabaci, is an important insect pest that transmits over 200 different plant viruses and causes serious damage to the production of cotton and Solanaceae vegetables. Cyantraniliprole is the first diamide insecticide, showing toxicity against B. tabaci. However, B. tabaci has developed resistance to this insecticide by upregulating the expressions of cytochrome P450 genes such as CYP6CX3, while there is limited information on the regulatory mechanism mediated by miRNA. In the present study, ten miRNAs were predicted to target CYP6CX3, in which miR-276-3p showed an inverse expression pattern with CYP6CX3 in two cyantraniliprole resistant strains and under cyantraniliprole exposure. A luciferase assay demonstrated that miR-2763p suppressed CYP6CX3 expression by pairing with residues 1445-1453. Overexpression or knockdown of miR276-3p directly impacted B. tabaci resistance to cyantraniliprole. In addition, exposure to cyantraniliprole led to a significant reduction in the expressions of five genes (drosha, dicer1, dicer2, Ago1, and Ago2A) associated with miRNA biogenesis. Suppressing genes such as drosha, dicer1, and Ago2A reduced the expression of miR-276-3p, increased CYP6CX3 expression, and decreased B. tabaci resistance to cyantraniliprole. These results improve our understanding of the role of miRNAs in P450 regulation and cyantraniliprole resistance in B. tabaci.

BACKGROUND:Tomato chlorosis virus (ToCV) is associated with tomato yellow leaf disorder diseases in more than 20 countries. ToCV can be transmitted in a semipersistent manner by whitefly vectors such as Bemisia tabaci. Controlling the vector pests by using chemical insecticides is an efficient and effective approach to reduce and interrupt the virus transmission. Pyrifluquinazon is a new pyridine azomethine derivative, showing insecticidal toxicity to sucking pests by disturbing their feeding behavior. However, limited attention has been paid to the performance of pyrifluquinazon against B. tabaci and ToCV transmission. RESULT:This study showed the lethal concentration of 50% (LC50 ) values of pyrifluquinazon to 22 B. tabaci field populations ranged from 0.54 to 2.44 mg L-1 , and the baseline susceptibility of B. tabaci to pyrifluquinazon was 1.24 mg L-1 with a 95% confidence limit of 0.35-1.85 mg L-1 . Pyrifluquinazon and afidopyropen did not show cross-resistance to dinotefuran and pymetrozine in B. tabaci, which both inhibited the feeding activities of B. tabaci. The antifeedant concentration of 50% (AFC50 ) values at 48 h were 0.70 mg L-1 for pyrifluquinazon and 2.13 mg L-1 for afidopyropen. Foliar application of pyrifluquinazon and afidopyropen reduced the ToCV transmission by 40.91% and 33.33%, respectively and significantly decreased the ToCV loads in tomato plants under laboratory conditions. CONCLUSION:These results provided new information about the effects of modulators of the vanilloid-type transient receptor potential channel on the toxicity to B. tabaci and inhibition of ToCV transmission. © 2023 Society of Chemical Industry.

Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a cosmopolitan insect pest causing serious damage to crop production. Cytochromes P450 (CYPs) of B. tabaci are widely known to be involved in the metabolic resistance to a variety of insecticides, continuously increasing the difficulty in controlling this pest. In this study, four P450 genes (CYP6CM1, CYP6CX1, CYP6CX3, and CYP402C1) in B. tabaci exhibited correlations with the resistance to imidacloprid. We have focused on trying to understand the function and metabolism capacity of CYP402C1. The expression profiles of CYP402C1 were examined by reverse transcription quantitative real-time PCR and fluorescence in situ hybridizations. Its role in resistance to imidacloprid was investigated by RNA interference, transgenic Drosophila melanogaster, and heterologous expression. The results showed that CYP402C1 was highly expressed in the active feeding stages of B. tabaci, such as nymphs and female adults. CYP402C1 was mainly expressed in midguts of nymphs and adults, especially in the filter chamber. Knockdown of CYP402C1 significantly decreased the resistance of B. tabaci to imidacloprid by 3.96-fold (50% lethal concentration: 186.46 versus 47.08 mg/L). Overexpression of CYP402C1 in a transgenic D. melanogaster line (Gal4 > UAS-CYP402C1) significantly increased the resistance to imidacloprid from 12.68- to 14.92-fold (129.01 and 151.80 mg/L versus 1925.14 mg/L). The heterologous expression of CYP402C1 showed a metabolism ability of imidacloprid (imidacloprid decreased by 12.51% within 2 h). This study provides new insights for CYP402C1 function in B. tabaci and will help develop new strategies in B. tabaci control and its insecticide resistance.

BACKGROUND Bemisia tabaci (Gennadius) is a serious agricultural pest worldwide. Neonicotinoids are the most important new class of synthetic insecticides used in the management of B. tabaci. However, B. tabaci populations have developed resistance to various active ingredients in neonicotinoids following long-term and widespread application. RESULTS Dinotefuran exhibited high toxicity against most B. tabaci field populations. One population (Din-R) with a high level of resistance to dinotefuran (255.6-fold) was first identified in the field. The Din-R population exhibited medium to high levels of resistance to all the tested neonicotinoid insecticides and a high level of resistance to spinetoram. Genetic inheritance analysis revealed that resistance to dinotefuran was incompletely recessive and polygenic. The synergist piperonyl butoxide significantly increased the toxicity of dinotefuran to Din-R. P450 activity in the Din-R population was 2.19-fold higher than in the susceptible population. RNA-sequencing analysis showed that 12 P450 genes were significantly upregulated in the Din-R population, of which CYP6DW5, CYP6JM1 and CYP306A1 were found to exhibit more than 3.00-fold higher expression in Din-R when using a reverse transcription quantitative real-time polymerase chain reaction. Expression of eight P450 genes was obviously induced by dinotefuran, and CYP6DW5 showed the highest expression level. After knockdown of CYP6DW5 in Din-R, the toxicity of dinotefuran increased significantly. CONCLUSION P450 had a crucial role in dinotefuran resistance in B. tabaci, and CYP6DW5 was involved in the resistance. These results provide important information for the management of resistance in B. tabaci and improve our understanding of the resistance mechanism of dinotefuran. (c) 2022 Society of Chemical Industry.

Cuticle sclerotization is critical for insect survival. Laccase2 (Lac2) is a phenol oxidase that plays a key role in cuticle formation and pigmentation in a variety of insects. However, the function of Lac2 in whitefly, Bemisia tabaci, remains unclear. In this study, we identified a BtLac2 gene in B. tabaci MEAM1 and found that BtLac2 was expressed in all stages. It was highly expressed in the egg stage, followed by nymph and adult. Moreover, the expression of BtLac2 was higher in the cuticle than in other tissues. Knockdown of BtLac2 in nymphs produced thinner and fragile cuticles, which significantly increased the mortality rate, extended the development duration of nymphs, and decreased the emergence rate of adults. This result demonstrates that BtLac2 plays an important role in the cuticle hardening of B. tabaci and suggests a potential management strategy using RNAi to knock down BtLac2 expression.

Bemisia tabaci is an important agricultural sucking pest, and it develops serious resistance to various insecticides. Although cytochrome P450 was involved in the resistance to cyantraniliprole, limited studies have been conducted on B. tabaci. In the present study, piperonyl butoxide significantly increased the toxicity of cyantraniliprole. P450 activities in two resistant populations were 1.97- and 2.17-fold higher than that in the susceptible population. Among 79 P450 genes, CYP6CX3 expressions in two resistant populations were 3.08- and 3.67-fold higher than that in the susceptible population. When CYP6CX3 was knocked down, the toxicity of cyantraniliprole increased significantly. The LC50 value of cyantraniliprole to the Drosophila melanogaster line overexpressing B. tabaci CYP6CX3 increased 7.34-fold. The content of cyantraniliprole was decreased by 25.74 ± 4.27% after mixing with CYP6CX3 and CPR for 2 h. These results suggested that the overexpression of CYP6CX3 was likely involved in the resistance to cyantraniliprole in B. tabaci.

The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is one of the most destructive pests in the world because of its serious damage to various crops and rapid development of insecticide resistance. Afidopyropen is a novel pyropene insecticide with high insecticidal activity against sucking insects and has been registered to control whitefly in China since 2019. In this study, 33 field populations of B. tabaci were collected across China between August 2019 and October 2020 and their cryptic species compositions were investigated. The toxicity of afidopyropen to B. tabaci were measured at different times, which was further compared to the toxicity of pymetrozine. The results showed that only Mediterranean (MED) and Middle East-Asia Minor 1 (MEAM1) species were detected in the field populations. The LC50 values of afidopyropen were significantly higher in the first five days, and subsequently became stable at a lower level after day five. The LC50 value of afidopyropen to field whitefly populations ranged from 1.15 to 4.52 mg/L, and the variation in susceptibility was 1.9-fold. The LC50 value of the mixed susceptible population was 2.31 mg/L, which was established as the whitefly susceptible baseline to afidopyropen in China. The resistance to pymetrozine in field populations ranged from 1.8- to 116.6-fold, but no cross-resistance between afidopyropen and pymetrozine was observed. Taken together, afidopyropen exhibited a great insecticidal potency against 33 field populations of B. tabaci in China and it did not show cross-resistance with pymetrozine, suggesting it could be considered as an effective insecticide in the insecticide resistance management (IRM) of B. tabaci.

Ryanodine receptors (RyRs) are the targets of diamide insecticides, which have been identified and characterized in a dozen insect pests of Lepidoptera, Hemiptera, Diptera and Coleoptera, but limited attention has been paid to the RyR in parasitoid natural enemies. Without this knowledge, it will hinder our effective and efficient application using both parasitoid natural enemies and diamide insecticides simultaneously in the integrated pest management (IPM). In this study, the full-length cDNA of RyR was cloned from Encarsia formosa (EfRyR), a parasitic wasp used worldwide for the biological control of whitefly. Its expression profile was examined in various tissues of E. formosa adults. The toxicities of four diamide insecticides to E. formosa were measured, and then the expression profile of EfRyR after 12 h and 24 h exposure to the LC50 dosages of diamide insecticides was investigated. The results showed that the full-length cDNA of EfRyR was 16, 778 bp including a 15, 345 bp open reading frame, and two alternative splice (AS) sites. Comparing to its expression in the abdomen, EfRyR was highly expressed in the head (11.9-fold) and the thorax (3.7-fold). The toxicities of four dimide insecticides against E. formosa from low to high were chlorantraniliprole (LC50 = 367.84 mg L-1), cyantraniliprole (221.72 mg L-1), cyclaniliprole (51.77 mg L-1), and tetrachlorantraniliprole (8.35 mg L-1). The expressions of EfRyR and its variants with AS were significantly increased after E. formosa adults were exposed to different diamide insecticides. This study improves our understanding of the RyR in parasitoid wasps and provides useful information on IPM by using E. formosa.

Cyantraniliprole is the first diamide insecticide to have cross-spectrum activ-ity against a broad range of insect orders.The insecticide,like other diamides,selectively acts on ryanodine receptor,destroys Ca2+ homeostasis,and ultimately causes insect death.Although expression regulations of genes associated with calcium signaling pathways are known to be involved in the response to diamides,little is known regarding the function of calmodulin (CaM),a typical Ca2+ sensor central in regulating Ca2+ homeostasis,in the stress response of insects to the insecticide.In this study,we cloned and identified the full-length complementary DNA of CaM in the whitefly,Bemisia tabaci (Gennadius),named BtCaM.Quantitative real-time reverse transcription polymerase chain reaction-based anal-yses showed that the messenger RNA level of BtCaM was rapidly induced from 1.51-to 2.43-fold by cyantraniliprole during 24 h.Knockdown of BtCaM by RNA interference increased the toxicity of cyantraniliprole in whiteflies by 42.85％.In contrast,BtCaM expression in Sf9 cells significantly increased the cells' tolerance to cyantraniliprole as much as 2.91-fold.In addition,the expression of BtCaM in Sf9 cells suppressed the rapid increase of intracellular Ca2+ after exposure to cyantraniliprole,and the maximum ampli-tude in the Sf9-BtCaM cells was only 34.9％ of that in control cells (Sf9-PIZ/V5).These results demonstrate that overexpression of BtCaM is involved in the stress response of B.tabaci to cyantraniliprole through regulation of Ca2+ concentration.As CaM is one of the most evolutionarily conserved Ca2+ sensors in insects,outcomes of this study may provide the first details of a universal insect response to diamide insecticides.

HomePlant DiseaseVol. 104, No. 3First Report of Leaf Spots and Necrosis Caused by Paraphaeosphaeria recurvifoliae on Yucca gloriosa in China PreviousNext DISEASE NOTES OPENOpen Access licenseFirst Report of Leaf Spots and Necrosis Caused by Paraphaeosphaeria recurvifoliae on Yucca gloriosa in ChinaTianbo Ding, Zhenbo Li, Lei Guo, and Jie LiTianbo DingKey Laboratory of Integrated Crop Pest Management of Shandong Province, College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao 266109, ChinaSearch for more papers by this author, Zhenbo LiShandong Plant Protection Station, Jinan, 250100, ChinaSearch for more papers by this author, Lei GuoKey Laboratory of Integrated Crop Pest Management of Shandong Province, College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao 266109, ChinaSearch for more papers by this author, and Jie Li†Corresponding author: Jie Li; E-mail Address: lijiepd@sina.comhttp://orcid.org/0000-0002-9013-6862Key Laboratory of Integrated Crop Pest Management of Shandong Province, College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao 266109, ChinaSearch for more papers by this author AffiliationsAuthors and Affiliations Tianbo Ding1 Zhenbo Li2 Lei Guo1 Jie Li1 † 1Key Laboratory of Integrated Crop Pest Management of Shandong Province, College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao 266109, China 2Shandong Plant Protection Station, Jinan, 250100, China Published Online:30 Dec 2019https://doi.org/10.1094/PDIS-07-19-1383-PDNAboutSectionsSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat Yucca gloriosa L. has been introduced to China as a garden plant because of its tolerance to low temperatures and attractive tubular flowers. In June 2018 and 2019, leaf spot and tissue necrosis appeared on Y. gloriosa plants at Chengyang campus and Laoshan Yangkou scenic area, both in Qingdao, Shandong Province, China. The initial symptoms were observed on the middle and lower older leaves as small, round or oval, dark brown leaf spots. Then, the leaf spot gradually expanded and became oval or irregularly round, with a clear dark brown border (leaf spot size: about 0.5 to 5 cm long and 0.5 to 1.5 cm wide). Dark fruiting bodies were observed in the center of the leaf spot. The disease symptoms subsequently spread to upper leaves of the plant, inducing necrosis and wilting of whole leaves. To determine an agent of this disease, 10 symptomatic leaves were collected from Chengyang campus and Laoshan Yangkou scenic area. Small pieces of tissue from each infected leaf were excised, surface disinfested in 75% ethanol solution for 30 s, and placed on potato dextrose agar (PDA) at 25°C in the dark for 5 days. Fungal cultures were then transferred to new PDA. For morphological description, the cultures were incubated at 27 ± 2°C for 10 days. Colonies on PDA (200 g/liter extract of boiled potatoes, 20 g/liter glucose, and 15 to 20 g/liter agar) at first were whitish to cream colored or greyish, and they reached an average diameter of 60 mm. Small black pycnidia were buried in mycelia at the late growth stage. Pycnidia were brown, ovoid, superficial to partly immersed, and 85 to 155 μm in diameter. Conidia produced were unicellular and were spherical or elliptic (5.5 × 4.6 μm in average size, n = 80), usually from hyaline to dark brown. The observed morphological features matched those described for Paraphaeosphaeria recurvifoliae (Lee et al. 2005; Pieczul and Perek 2016). For further identification, the internal transcribed spacer (ITS) region (ITS1-5.8S-ITS2) of nuclear rDNA was amplified from the extracted genomic DNA with primers ITS1 and ITS4 (Berbee et al. 1999), followed by the sequencing of the PCR product (569 bp). All rDNA sequences of tested isolates were identical. One was deposited in GenBank (accession no. MN121340). BLAST analysis revealed more than 99% identity to the sequence of P. recurvifoliae (AY957476 and KT350983). To confirm Koch’s postulates, 12 Y. gloriosa plants (about 2 years old) were randomly collected from Chengyang campus. P. recurvifoliae spores were placed on the surface of 24 leaves (about 5 months old) of six Y. gloriosa plants, with 10 μl of P. recurvifoliae conidial suspension (2.6 × 105 conidia/ml) for each leaf. Distilled water was individually placed on the surface of 24 control leaves. The experiments were performed in a greenhouse (27 ± 2°C, 75 ± 5% relative humidity, and a photoperiod of 14 h light/10 h dark). After 10 to 15 days, the inoculated plants developed symptoms similar to those observed in naturally infected plants, whereas control plants were symptomless. The percent incidence and disease severity index (Islam and Borthakur 2012; Zhao et al. 2014) of leaves inoculated with strain MN121340 were 87.5% and 43.75, respectively. The fungal pathogen was reisolated, and the resulting ITS sequence was identical to the inoculated P. recurvifoliae. Based on these results, the disease on Y. gloriosa was caused by P. recurvifoliae. To our knowledge, this is the first report of P. recurvifoliae occurrence on Y. gloriosa in China. This finding raises awareness and concern about this emerging disease, and control strategies should be followed.The author(s) declare no conflict of interest.References:Berbee, M. L., et al. 1999. Mycologia 91:964. https://doi.org/10.1080/00275514.1999.12061106 Crossref, ISI, Google ScholarIslam, N. F., and Borthakur, S. K. 2012. Plant Pathol. Quar. 2:75. https://doi.org/10.5943/ppq/2/1/11 Crossref, Google ScholarLee, H. B., et al. 2005. Fungal Divers. 20:71. ISI, Google ScholarPieczul, K., and Perek, A. 2016. Plant Dis. 100:1018. https://doi.org/10.1094/PDIS-10-15-1193-PDN Link, ISI, Google ScholarZhao, B., et al. 2014. Saudi J. Biol. Sci. 21:374. https://doi.org/10.1016/j.sjbs.2013.10.004 Crossref, ISI, Google ScholarThe author(s) declare no conflict of interest.Funding: This research was supported by grants from the National Natural Science Foundation of China (31401809).DetailsFiguresLiterature CitedRelated Vol. 104, No. 3 March 2020SubscribeISSN:0191-2917e-ISSN:1943-7692 DownloadCaptionPathogenicity of Lasiodiploidia pseudotheobromae in a coffee plant 3 days after inoculation (R. L. Freitas-Lopes et al.). Photo credit: U. P. Lopes. Seedling blight of soybean caused by soilborne pathogens (J. R. Lamichhane et al.). Photo credit: M. I. Chilvers. Metrics Downloaded 3,087 times Article History Issue Date: 3 Mar 2020Published: 30 Dec 2019First Look: 4 Nov 2019Accepted: 30 Oct 2019 Pages: 986-986 Information© 2020 The American Phytopathological SocietyFundingNational Natural Science Foundation of ChinaGrant/Award Number: 31401809KeywordsParaphaeosphaeria recurvifoliaeYucca gloriosaChinaThe author(s) declare no conflict of interest.

[目的]前期研究发现烟粉虱Bemisia tabaci MED隐种2个钙离子结合蛋白(BtCaBP1和BtCaBP2)参与烟粉虱对溴氰虫酰胺的应激反应.本研究旨在通过RNAi干扰钙离子结合蛋白基因,系统揭示钙离子结合蛋白对烟粉虱的生物学影响.[方法]通过dsRNA饲喂法分别干扰烟粉虱MED隐种成虫钙离子结合蛋白基因BtCaBP1和BtCaBP2后,qPCR检测BtCaBP1和BtCaBP2的表达量;观测并比较了RNAi 3 d后处理组(分别饲喂dsBtCaBP1和dsBtCaBP2)和对照组(饲喂dsEGFP)间烟粉虱MED隐种亲代成虫(雌雄)寿命、单雌产卵量以及子一代的卵孵化率和成虫前期发育历期等生物学参数.[结果]分别饲喂dsBtCaBP1和dsBtCaBP23 d后,处理组烟粉虱MED隐种靶标基因BtCaBP1和BtCaBP2的表达量较对照组均显著降低.处理组中干扰BtCaBP2后的亲代烟粉虱MED隐种成虫寿命(雌:15.46±1.24d;雄:13.84±0.38 d)较对照组的(雌:13.25±0.58 d;雄:12.67±0.65 d)显著延长;处理组的单雌产卵量(39.53±3.04)比对照组的(76.06±4.76)显著降低;处理组子一代卵孵化率(81.58％±4.42％)比对照组的(87.22％±3.21％)显著降低;子一代成虫前期发育历期处理组(24.42±1.09 d)比对照组的(27.52±1.73 d)显著缩短.而干扰BtCaBP1基因后,亲代及子一代上述生物学参数没有显著变化.[结论]干扰BtCaBP1和BtCaBP2对烟粉虱MED隐种具有不同的生物学效应,该结果为后续进一步研究钙离子结合蛋白的生物学功能提供了参考.

An unwelcome side effect of the globalization of the world's economy and dramatic increase in human mobility and trade has been a marked increase in species invasions that have posed severe threats to the ecological, economic, and/or social stability of the introduced regions. In this review, we analyzed the application of molecular markers in invasion genetics of invasive alien insect pests (IAIPs) in China based on a bibliometric survey. Our report discusses the considerable progress that has been made during the past two decades in understanding the invasion genetics of IAIPs in China. We reviewed the major findings in the main topics including the effects of origin and routes of invasion on genetic structure, spatial and temporal genetic changes, factors contributing to the genetic changes of IAIPs, and genetic mechanisms involved in IAIPs' invasions. On the other hand, some of these research areas remain relatively unexplored in China, especially those pertaining to spatial and temporal genetic changes of IAIPs and genetic mechanisms of IAIPs' invasions. Finally, the future research prospects of IAIPs in China are discussed. We hope this review will stimulate an interest in and provide an increased understanding of the field of invasion genetics of IAIPs in China, and provide a basis for future research in this area.

[目的]了解苹果绵蚜Eriosoma lanigerum对不同类别杀虫剂的抗药水平,为田间苹果绵蚜化学防控过程中的药剂选择提供理论基础.[方法]2018年6-7月间,采用玻璃管药膜法测定了3省14个地区苹果绵蚜对阿维菌素、高效氯氰菊酯和吡虫啉的抗药性.[结果]研究表明,西安杨凌地区苹果绵蚜种群对阿维菌素的抗性水平最低,LC50值仅为6.813 mg/L;烟台招远地区苹果绵蚜种群对阿维菌素的抗性水平最高,LC50值为79.496 mg/L.多数地区苹果绵蚜种群对高效氯氰菊酯的抗药水平较低,其中烟台龙口地区抗药水平最低,LC50值为4.341 mg/L,烟台栖霞地区抗药性最高,LC50值为37.689mg/L.青岛即墨地区苹果绵蚜种群对吡虫啉的抗性水平最低,LC50值仅为5.261 mg/L;烟台招远地区苹果绵蚜种群对吡虫啉已经产生了中等水平的抗性(RR=10.859),LC50值为57.128 mg/L.不同虫态抗药性检测表明,除了烟台蓬莱地区的若蚜对阿维菌素和吡虫啉出现了抗药性提高的现象外,其它大部分苹果绵蚜3龄若蚜对药剂的抗性与成蚜相近.[结论]苹果绵蚜在北方大部分地区对常用杀虫剂的抗药性保持在低水平或敏感状态.在今后防治中应继续坚持交替轮换的用药原则,防止苹果绵蚜抗药性的产生.

Resistance to multiple insecticides has become the biggest challenge to controlling Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae). In attempts to remedy the problem, four insecticides with novel modes of action (cyclaniliprole, cyantraniliprole, sulfoxaflor, and flupyradifurone) have recently been introduced to control B. tabaci. In the present study, we collected 18 B. tabaci populations in China from 2018 to 2019 to determine their resistance levels to six insecticides including the above four insecticides and two representative traditional insecticides (bifenthrin and imidacloprid). The results showed cyclaniliprole with LC50 values ranging from 3.4 to 21.2 mg/L was the most toxic insecticide to B. tabaci field populations and their average LC50 of 13.5 mg/L was used for the susceptible baseline to cyclaniliprole. The other three newly introduced insecticides (cyantraniliprole, sulfoxaflor, and flupyradifurone) also exhibited high toxicity to the field populations, however, the two traditional insecticides tested were of low toxicity with LC50 values ranging from 16.9 to 296.6 mg/L and from 33.1 to 397.0 mg/L for bifenthrin and imidacloprid, respectively. These results demonstrate that the newly introduced insecticides can currently be considered as effective alternative insecticides in insect resistance management programs for B. tabaci in China.

Ca2+-binding proteins (CaBPs) are widely distributed as Ca2+ sensor relay proteins that regulate various cellular processes, including Ca2+ homeostasis. Diamide insecticides such as cyantraniliprole kill insects by disrupting the Ca2+ homeostasis in muscle cells. However, less attention has been paid to the roles of CaBPs in response to insecticides. In this study, two CaBP genes (BtCaBP1 and BtCaBP2) were identified in the whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), and their functions in response to cyantraniliprole were investigated. After expression of BtCaBP1 and BtCaBP2 in vitro, the results of Ca2+ imaging and cytotoxicity assay revealed that the overexpression of each of the BtCaBPs stabilized Ca2+ concentration in the cytoplasm after exposure to cyantraniliprole and decreased the toxicity of cyantraniliprole against Sf9 cells. However, the knockdown of BtCaBP1 or BtCaBP2 in vivo significantly increased the toxicity of cyantraniliprole to B. tabaci. Taken together, these results provide evidence that BtCaBP1 and BtCaBP2 play a role in response to cyantraniliprole exposure through stabilization of Ca2+ concentration in whiteflies.