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Shaoli Wang - One of the best experts on this subject based on the ideXlab platform.
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infection of tomato by tomato yellow leaf curl virus alters the foraging behavior and parasitism of the parasitoid encarsia formosa on Bemisia tabaci
Journal of Asia-pacific Entomology, 2018Co-Authors: Yanyan He, Qingjun Wu, Youjun Zhang, Shaoli WangAbstract:Abstract Encarsia formosa Gahan is a solitary endoparasitoid that is commercially reared and released for augmentative biological control of whiteflies including Bemisia tabaci (Gennadius). Bemisia tabaci biotypes B and Q are two most invasive species that greatly reduce crop yields in China by feeding on plant sap and by transmitting Tomato Yellow Leaf Curl Virus (TYLCV). The effects of TYLCV infection of tomato on E. formosa foraging on B. tabaci B and Q are unknown. In Y-tube olfactometer assays in the present study, E. formosa significantly preferred TYLCV-infected tomato plants over TYLCV-free plants. The wasp females also significantly preferred TYLCV-infected tomato plants infested with 3rd-instar nymphs of B. tabaci biotype Q over TYLCV-free plants with biotype Q nymphs. However, no significant differences were observed when B. tabaci biotype B was infested on tomato plants. The oviposition bioassays confirmed that TYLCV infection on tomato plants resulted in the recruitment of parasitoids. These results indicate that TYLCV-infection of tomato increase the foraging of E. formosa on B. tabaci, as differs on the B and Q biotypes.
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virus infected plants altered the host selection of encarsia formosa a parasitoid of whiteflies
Frontiers in Physiology, 2017Co-Authors: Gong Chen, Qingjun Wu, Youjun Zhang, Shaoli WangAbstract:The sweetpotato whitefly Bemisia tabaci (Gennadius) is one of the most invasive pest species worldwide. Q and B biotypes are the two most devastating species within the B. tabaci complex. Bemisia tabaci can vector hundreds of plant viruses that seriously threaten crop production. Endoparasitoid, Encarsia formosa Gahan, is widely used to control whiteflies, however, little is known about the effects of virus-infected plants on E. formosa parasitism of B. tabaci. Here, we reported that tomato, which was infected with Tomato Yellow Leaf Curl Virus (TYLCV), altered the host selection of E. formosa between B. tabaci Q and B biotypes. On healthy tomato plants, parasitism and host selection by E. formosa did not differ between the 3rd-instar nymphs of B. tabaci Q and B biotypes. On TYLCV-infected tomato plants, however, B. tabaci Q biotype were significantly more attractive to E. formosa than B biotype. When TYLCV-infected tomato plants were infested with B. tabaci Q or B biotype, volatile profiles differed quantitatively but not qualitatively. Olfactometer assays suggested that the preference of E. formosa to Q over B biotype was associated with an elevated level of β-Myrcene, β-Ocimene, β-Caryophyllene, and α-Humulene from TYLCV-infected tomato plants. Key Words: Encarsia formosa, Bemisia tabaci, Tomato Yellow Leaf Curl Virus, Host selection, Plant volatiles
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Virus-Infected Plants Altered the Host Selection of Encarsia formosa, a Parasitoid of Whiteflies
Frontiers Media S.A., 2017Co-Authors: Xin Liu, Gong Chen, Youjun Zhang, Wen Xie, Shaoli WangAbstract:The sweetpotato whitefly Bemisia tabaci (Gennadius) is one of the most invasive pest species worldwide. Q and B biotypes are the two most devastating species within the B. tabaci complex. Bemisia tabaci can vector hundreds of plant viruses that seriously threaten crop production. Endoparasitoid, Encarsia formosa Gahan, is widely used to control whiteflies, however, little is known about the effects of virus-infected plants on E. formosa parasitism of B. tabaci. Here, we reported that tomato, which was infected with Tomato Yellow Leaf Curl Virus (TYLCV), altered the host selection of E. formosa between B. tabaci Q and B biotypes. On healthy tomato plants, parasitism and host selection by E. formosa did not differ between the 3rd-instar nymphs of B. tabaci Q and B biotypes. On TYLCV-infected tomato plants, however, B. tabaci Q biotype were significantly more attractive to E. formosa than B biotype. When TYLCV-infected tomato plants were infested with B. tabaci Q or B biotype, volatile profiles differed quantitatively but not qualitatively. Olfactometer assays suggested that the preference of E. formosa to Q over B biotype was associated with an elevated level of β-Myrcene, β-Ocimene, β-Caryophyllene, and α-Humulene from TYLCV-infected tomato plants
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Glutathione S-transferases are involved in thiamethoxam resistance in the field whitefly Bemisia tabaci Q (Hemiptera: Aleyrodidae).
Pesticide Biochemistry and Physiology, 2016Co-Authors: Xin Yang, Ze-zong Yang, Shaoli Wang, Chao He, Qingjun WuAbstract:The whitefly, Bemisia tabaci, has developed a high level of resistance to thiamethoxam, a second generation neonicotinoid insecticide that has been widely used to control this pest. In this study, we assessed the level of cross-resistance, the activities of detoxifying enzymes, and the expression profiles of 23 glutathione S-transferase (GST) genes in a thiamethoxam-resistant ant and -susceptible strain of Bemisia tabaci Q. The thiamethoxam-resistant strain showed a moderate level of cross-resistance to another nicotinoid insecticide imidacloprid, a low level of cross-resistance to acetamiprid and nitenpyram, and no significant cross-resistance to abamectin and bifenthrin. Among detoxifying enzymes, only GSTs had significantly higher activity in the resistant strain than in the susceptible strain. Seven of 23 GST genes were over-expressed in the resistant strain relative to the susceptible strain. Using the technology of RNA interference to knockdown a GST gene (GST14), the results showed that silencing GST14 increased the mortality of whiteflies to thiamethoxam in Bemisia tabaci.
Anastasia Tsagkarakou - One of the best experts on this subject based on the ideXlab platform.
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insecticide resistance in Bemisia tabaci homoptera aleyrodidae populations from crete
Pest Management Science, 2005Co-Authors: Emmanouil Roditakis, Nikos E. Roditakis, Anastasia TsagkarakouAbstract:The resistance levels to α-cypermethrin, bifenthrin, pirimiphos-methyl, endosulfan and imidacloprid were determined in Bemisia tabaci (Gennadius) from Crete. Five B tabaci populations collected from greenhouse and outdoor crops were bioassayed and compared with a reference susceptible strain. Bemisia tabaci collected in a floriculture greenhouse exhibited the highest resistance against all insecticides: at LC50, resistance factors were 23-fold for bifenthrin, 80-fold for α-cypermethrin, 18-fold for pirimiphos-methyl, 58-fold for endosulfan and 730-fold for imidacloprid. A population collected on outdoor melons was more susceptible than the reference strain against all insecticides tested, suggesting the occurrence of local highly susceptible B tabaci populations in 'refugia'. In pairwise comparisons of resistance levels, correlation was observed between the LC50 values of the pyrethroid insecticides bifenthrin and α-cypermethrin. 2005 Society of Chemical Industry
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insecticide resistance in Bemisia tabaci homoptera aleyrodidae populations from crete
Pest Management Science, 2005Co-Authors: Emmanouil Roditakis, Nikos E. Roditakis, Anastasia TsagkarakouAbstract:The resistance levels to alpha-cypermethrin, bifenthrin, pirimiphos-methyl, endosulfan and imidacloprid were determined in Bemisia tabaci (Gennadius) from Crete. Five B tabaci populations collected from greenhouse and outdoor crops were bioassayed and compared with a reference susceptible strain. Bemisia tabaci collected in a floriculture greenhouse exhibited the highest resistance against all insecticides: at LC50, resistance factors were 23-fold for bifenthrin, 80-fold for alpha-cypermethrin, 18-fold for pirimiphos-methyl, 58-fold for endosulfan and 730-fold for imidacloprid. A population collected on outdoor melons was more susceptible than the reference strain against all insecticides tested, suggesting the occurrence of local highly susceptible B tabaci populations in 'refugia'. In pairwise comparisons of resistance levels, correlation was observed between the LC50 values of the pyrethroid insecticides bifenthrin and alpha-cypermethrin.
Qingjun Wu - One of the best experts on this subject based on the ideXlab platform.
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infection of tomato by tomato yellow leaf curl virus alters the foraging behavior and parasitism of the parasitoid encarsia formosa on Bemisia tabaci
Journal of Asia-pacific Entomology, 2018Co-Authors: Yanyan He, Qingjun Wu, Youjun Zhang, Shaoli WangAbstract:Abstract Encarsia formosa Gahan is a solitary endoparasitoid that is commercially reared and released for augmentative biological control of whiteflies including Bemisia tabaci (Gennadius). Bemisia tabaci biotypes B and Q are two most invasive species that greatly reduce crop yields in China by feeding on plant sap and by transmitting Tomato Yellow Leaf Curl Virus (TYLCV). The effects of TYLCV infection of tomato on E. formosa foraging on B. tabaci B and Q are unknown. In Y-tube olfactometer assays in the present study, E. formosa significantly preferred TYLCV-infected tomato plants over TYLCV-free plants. The wasp females also significantly preferred TYLCV-infected tomato plants infested with 3rd-instar nymphs of B. tabaci biotype Q over TYLCV-free plants with biotype Q nymphs. However, no significant differences were observed when B. tabaci biotype B was infested on tomato plants. The oviposition bioassays confirmed that TYLCV infection on tomato plants resulted in the recruitment of parasitoids. These results indicate that TYLCV-infection of tomato increase the foraging of E. formosa on B. tabaci, as differs on the B and Q biotypes.
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virus infected plants altered the host selection of encarsia formosa a parasitoid of whiteflies
Frontiers in Physiology, 2017Co-Authors: Gong Chen, Qingjun Wu, Youjun Zhang, Shaoli WangAbstract:The sweetpotato whitefly Bemisia tabaci (Gennadius) is one of the most invasive pest species worldwide. Q and B biotypes are the two most devastating species within the B. tabaci complex. Bemisia tabaci can vector hundreds of plant viruses that seriously threaten crop production. Endoparasitoid, Encarsia formosa Gahan, is widely used to control whiteflies, however, little is known about the effects of virus-infected plants on E. formosa parasitism of B. tabaci. Here, we reported that tomato, which was infected with Tomato Yellow Leaf Curl Virus (TYLCV), altered the host selection of E. formosa between B. tabaci Q and B biotypes. On healthy tomato plants, parasitism and host selection by E. formosa did not differ between the 3rd-instar nymphs of B. tabaci Q and B biotypes. On TYLCV-infected tomato plants, however, B. tabaci Q biotype were significantly more attractive to E. formosa than B biotype. When TYLCV-infected tomato plants were infested with B. tabaci Q or B biotype, volatile profiles differed quantitatively but not qualitatively. Olfactometer assays suggested that the preference of E. formosa to Q over B biotype was associated with an elevated level of β-Myrcene, β-Ocimene, β-Caryophyllene, and α-Humulene from TYLCV-infected tomato plants. Key Words: Encarsia formosa, Bemisia tabaci, Tomato Yellow Leaf Curl Virus, Host selection, Plant volatiles
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Glutathione S-transferases are involved in thiamethoxam resistance in the field whitefly Bemisia tabaci Q (Hemiptera: Aleyrodidae).
Pesticide Biochemistry and Physiology, 2016Co-Authors: Xin Yang, Ze-zong Yang, Shaoli Wang, Chao He, Qingjun WuAbstract:The whitefly, Bemisia tabaci, has developed a high level of resistance to thiamethoxam, a second generation neonicotinoid insecticide that has been widely used to control this pest. In this study, we assessed the level of cross-resistance, the activities of detoxifying enzymes, and the expression profiles of 23 glutathione S-transferase (GST) genes in a thiamethoxam-resistant ant and -susceptible strain of Bemisia tabaci Q. The thiamethoxam-resistant strain showed a moderate level of cross-resistance to another nicotinoid insecticide imidacloprid, a low level of cross-resistance to acetamiprid and nitenpyram, and no significant cross-resistance to abamectin and bifenthrin. Among detoxifying enzymes, only GSTs had significantly higher activity in the resistant strain than in the susceptible strain. Seven of 23 GST genes were over-expressed in the resistant strain relative to the susceptible strain. Using the technology of RNA interference to knockdown a GST gene (GST14), the results showed that silencing GST14 increased the mortality of whiteflies to thiamethoxam in Bemisia tabaci.
Emmanouil Roditakis - One of the best experts on this subject based on the ideXlab platform.
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insecticide resistance in Bemisia tabaci homoptera aleyrodidae populations from crete
Pest Management Science, 2005Co-Authors: Emmanouil Roditakis, Nikos E. Roditakis, Anastasia TsagkarakouAbstract:The resistance levels to α-cypermethrin, bifenthrin, pirimiphos-methyl, endosulfan and imidacloprid were determined in Bemisia tabaci (Gennadius) from Crete. Five B tabaci populations collected from greenhouse and outdoor crops were bioassayed and compared with a reference susceptible strain. Bemisia tabaci collected in a floriculture greenhouse exhibited the highest resistance against all insecticides: at LC50, resistance factors were 23-fold for bifenthrin, 80-fold for α-cypermethrin, 18-fold for pirimiphos-methyl, 58-fold for endosulfan and 730-fold for imidacloprid. A population collected on outdoor melons was more susceptible than the reference strain against all insecticides tested, suggesting the occurrence of local highly susceptible B tabaci populations in 'refugia'. In pairwise comparisons of resistance levels, correlation was observed between the LC50 values of the pyrethroid insecticides bifenthrin and α-cypermethrin. 2005 Society of Chemical Industry
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insecticide resistance in Bemisia tabaci homoptera aleyrodidae populations from crete
Pest Management Science, 2005Co-Authors: Emmanouil Roditakis, Nikos E. Roditakis, Anastasia TsagkarakouAbstract:The resistance levels to alpha-cypermethrin, bifenthrin, pirimiphos-methyl, endosulfan and imidacloprid were determined in Bemisia tabaci (Gennadius) from Crete. Five B tabaci populations collected from greenhouse and outdoor crops were bioassayed and compared with a reference susceptible strain. Bemisia tabaci collected in a floriculture greenhouse exhibited the highest resistance against all insecticides: at LC50, resistance factors were 23-fold for bifenthrin, 80-fold for alpha-cypermethrin, 18-fold for pirimiphos-methyl, 58-fold for endosulfan and 730-fold for imidacloprid. A population collected on outdoor melons was more susceptible than the reference strain against all insecticides tested, suggesting the occurrence of local highly susceptible B tabaci populations in 'refugia'. In pairwise comparisons of resistance levels, correlation was observed between the LC50 values of the pyrethroid insecticides bifenthrin and alpha-cypermethrin.
Jianyang Guo - One of the best experts on this subject based on the ideXlab platform.
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inaccessibility to double stranded rnas in plastids restricts rna interference in Bemisia tabaci whitefly
Pest Management Science, 2020Co-Authors: Yi Dong, Yong Yang, Zican Wang, Jianyang Guo, Ling Chang, Jiang ZhangAbstract:BACKGROUND: RNA interference (RNAi) has emerged as a promising technology for insect pest control. Because of the accumulation of high levels of long double‐stranded RNAs (dsRNAs) in plastids, it was previously shown that expression of dsRNAs from plastid genome led to higher mortality of some insect pests with chewing mouthparts than dsRNAs expression from nuclear genome. However, whether plastid‐expressed dsRNAs have effects on phloem sap‐sucking pests is unknown. In this study, we compared the RNAi effects of nuclear transgenic and transplastomic plants on the whitefly Bemisia tabaci, a serious sap‐sucking pest. RESULTS: Nuclear transgenic and transplastomic tobacco plants were developed for the expression of dsRNA against BtACTB gene of Bemisia tabaci, respectively. Feeding nuclear transgenic plants to Bemisia tabaci resulted in reduced gene expression of BtACTB and survival rate, and impaired fecundity of Bemisia tabaci. We did not observe any effects of transplastomic plants on Bemisia tabaci fitness. Furthermore, we found that the inability of B. tabaci to obtain dsRNAs from plastids might restrict its RNAi responses. CONCLUSION: Our study indicated that the expression of dsRNAs in nuclear transgenic plants was more effective than that in transplastomic plants for the control of Bemisia tabaci. The inaccessibility of Bemisia tabaci to plastids contributes to the inefficiency of plastid‐mediated RNAi. Our findings are of great significance to future optimization of transgenically delivered RNAi approaches for efficient controlling of sap‐sucking pests. © 2020 Society of Chemical Industry
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enhanced vitellogenesis in a whitefly via feeding on a begomovirus infected plant
PLOS ONE, 2012Co-Authors: Jianyang Guo, Shusheng Liu, Shengzhang Dong, Xiuling Yang, Lu Cheng, Fanghao Wan, Xueping ZhouAbstract:Background The MEAM1 (B biotype) Bemisia tabaci (Gennadius) is one of the most widespread and damaging whitefly cryptic species. Our previous studies discovered that the MEAM1 whitefly indirectly benefits from interactions with the tomato yellow leaf curl China virus (TYLCCNV) via accelerated ovarian development and increased fecundity. However, the physiological mechanism of begomoviruse-infected plants acting on the reproduction of the insect vector was unknown.