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Primitivo Caballero - One of the best experts on this subject based on the ideXlab platform.
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stage specific insecticidal characteristics of a nucleopolyhedrovirus isolate from chrysodeixis chalcites enhanced by Optical Brighteners
Pest Management Science, 2014Co-Authors: Alexandra Bernal, Oihane Simon, Trevor Williams, Primitivo CaballeroAbstract:BACKGROUND: Chrysodeixischalcites is a major noctuid pest of banana crops in the Canary Islands. The stage-specific susceptibility of this pest to C.chalcites single nucleopolyhedrovirus (ChchSNPV-TF1) was determined, as well as the effect of selected Optical Brighteners as enhancers of primary infection. RESULTS: Susceptibility to ChchSNPV-TF1 occlusion bodies (OBs) decreased as larval stage increased; second instars (L2) were 10000-fold more susceptible than sixth instars (L6). Virus speed of kill was 42h faster in L2 than in L6. OB production increased in late instars; L6 larvae produced 23-fold more OBs than L4. Addition of 10mgmL −1 Tinopal enhanced OB pathogenicity by 4.43- to 397-fold depending on instar, whereas 10 µLmL −1 Leucophor resulted in potentiation of OB pathogenicity from 1.46to 143-fold. Mean time to death decreased by 14 to 26h when larvae consumed OBs in mixtures with 10mgmL −1 Tinopal, or 10 µLmL −1 Leucophor, although in these treatments OB yields were reduced by up to 8.5-fold (Tinopal) or up to 3.8-fold (Leucophor). CONCLUSION: These results have clear applications for the use of ChchSNPV-TF1 as a biological insecticide in control programs against C.chalcites in the Canary Islands. c � 2013 Society of Chemical Industry Supporting information may be found in the online version of this article.
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application of juvenile hormone analogue and Optical brightener technologies to the production of spodoptera frugiperda multiple nucleopolyhedrovirus
Proceedings of the IOBC WPRS Working Group "Insect Pathogens and Insect Parasitic Nematodes" and COST Action 862 "Bacterial Toxins for Insect Control", 2009Co-Authors: Rodrigo Lasa, I Moreno, N Crickmore, I Glazer, R. U. Ehlers, Jurg Enkerli, Trevor Williams, Primitivo Caballero, M Lopezferber, Cezary TkaczukAbstract:Final instar larvae of Spodoptera frugiperda grew to a maximum weight of 622 ± 13 mg on diet treated with 1% piriproxyfen, a juvenile horrnone analogue (JHA). or 695 ± 17 mg on diet treated with 1% fenoxycarb, both of which were significantly greater weights than observed in larvae that developed on untreated diet (512 ± 9 mg). Virus mortality in insects inoculated with SfMNPV occlusion bodies (OBs) was approximately 50% in all treatments, reflecting the resistance of late instar S. frugiperda larvae to infection. However, JHA treatment did not result in a significant increases in the total OB yield, or OBs per mg larval weight, compared to untreated infected insects. We deterrnined whether resistance to infection could be overcome by inoculation with mixtures of OBs and Optical Brighteners. Potentiation of OB activity was >2500-fold in mixtures with 1% Leukophor AP or Blankophor BA, or >15-fold in mixtures with 0.1 % of either brightener, compared to SfMNPV OBs alone. We conclude that SfMNPV production was 110t increased in JHA treated larvae because the JHA did not result in a supernumerary instar in S. frugiperda. However, Optical Brighteners were highly effective in overcoming developmental resistance to infection in this species.
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Effects of stilbene Optical Brighteners on the insecticidal activity of Bacillus thuringiensis and a single nucleopolyhedrovirus on Helicoverpa armigera
Biological Control, 2008Co-Authors: María A. Ibargutxi, Delia Muñoz, Alexandra Bernal, Inigo Ruiz De Escudero, Primitivo CaballeroAbstract:The incorporation of certain stilbene Optical Brighteners into virus-based formulations has been demonstrated to increase viral pathogenicity (as indicated by reduced LD/LC50 values) but their effect on Bacillus thuringiensis activity has been scarcely investigated. We determined the effect of nine Optical Brighteners on the insecticidal activity of B. thuringiensis ser. kurstaki HD-1 strain (Bt HD-1) on Helicoverpa armigera and also compared the effect of two Optical Brighteners on the insecticidal activity of Bt HD-1 and occlusion bodies (OBs) of a Spanish isolate of H. armigera single nucleocapsid nucleopolyhedrovirus (HearNPV-SP1). Blankophor CLE, Blankophor DRS, Blankophor ER, and Leucophor SAC significantly increased the pathogenicity of Bt HD-1. In contrast, Tinopal UNPA-GX, Tinopal CBS, Blankophor BA, Leucophor AP, and Leucophor UO had an adverse or no effect on its insecticidal activity. Mixtures of HearNPV-SP1 OBs with Tinopal UNPA-GX or Leucophor UO resulted in 31.4- and 11.4-fold increases in pathogenicity, respectively, at 1%, and 11.4- and 6.3-fold increases in pathogenicity, respectively, at 0.1%, compared to the OBs alone. However, none of these Brighteners increased Bt HD-1 activity. These results appear consistent with the hypothesis that the enhancement of HearNPV-SP1 pathogenicity and the null or antagonistic effects observed in Bt HD-1 against H. armigera were due to Optical brightener-mediated degradation of the peritrophic membrane, but additional systematic studies involving a broad range of Brighteners and electron microscope observations are required to confirm this premise.
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Optical Brighteners do not influence covert baculovirus infection of Spodoptera frugiperda.
Applied and Environmental Microbiology, 2005Co-Authors: Anamabel Martinez, Miguel López-ferber, Trevor Williams, Primitivo CaballeroAbstract:Covert infection with Spodoptera frugiperda multiple nucleopolyhedrovirus, detected by reverse transcription-PCR of virus gene transcripts (ie-0 and polh), was not significantly affected by the presence of an Optical brightener (Tinopal UNPA-GX), indicating no change in virus virulence. Detection of the covert infection was dependent on insect life stage and the viral mRNA used for diagnosis.
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formulation with an Optical brightener does not increase probability of developing resistance to spodoptera frugiperda nucleopolyhedrovirus in the laboratory
Journal of Economic Entomology, 2004Co-Authors: Anamabel Martinez, Maider Villanueva, Nagore Miralles, Ivan San Martin, Estibaliz Lopez, Primitivo Caballero, Trevor WilliamsAbstract:Abstract Stilbene-derived Optical Brighteners can markedly enhance the insecticidal activity of certain baculoviruses. We evaluated the influence of an Optical brightener on the rate at which Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) developed resistance to nucleopolyhedrovirus (SfMNPV). Two laboratory colonies of S. frugiperda were inoculated with an LC50 of SfMNPV, in the absence or presence of the Optical brightener Tinopal LPW (0.1%), over a period of two and 11 generations, in the first and second experiment, respectively. Compared with the initial susceptibility of the insect colony, resistance ratios of 11- and 12-fold were observed after two generations of treatment with SfMNPV + Tinopal LPW and SfMNPV alone. Similar, but variable degrees of resistance were observed in the long-term experiment with resistance ratios of 8- to 35-fold after seven to 11 generations. The presence of Tinopal LPW alone, or in mixtures with SfMNPV, did not cause any systematic change in insect resistanc...
Trevor Williams - One of the best experts on this subject based on the ideXlab platform.
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stage specific insecticidal characteristics of a nucleopolyhedrovirus isolate from chrysodeixis chalcites enhanced by Optical Brighteners
Pest Management Science, 2014Co-Authors: Alexandra Bernal, Oihane Simon, Trevor Williams, Primitivo CaballeroAbstract:BACKGROUND: Chrysodeixischalcites is a major noctuid pest of banana crops in the Canary Islands. The stage-specific susceptibility of this pest to C.chalcites single nucleopolyhedrovirus (ChchSNPV-TF1) was determined, as well as the effect of selected Optical Brighteners as enhancers of primary infection. RESULTS: Susceptibility to ChchSNPV-TF1 occlusion bodies (OBs) decreased as larval stage increased; second instars (L2) were 10000-fold more susceptible than sixth instars (L6). Virus speed of kill was 42h faster in L2 than in L6. OB production increased in late instars; L6 larvae produced 23-fold more OBs than L4. Addition of 10mgmL −1 Tinopal enhanced OB pathogenicity by 4.43- to 397-fold depending on instar, whereas 10 µLmL −1 Leucophor resulted in potentiation of OB pathogenicity from 1.46to 143-fold. Mean time to death decreased by 14 to 26h when larvae consumed OBs in mixtures with 10mgmL −1 Tinopal, or 10 µLmL −1 Leucophor, although in these treatments OB yields were reduced by up to 8.5-fold (Tinopal) or up to 3.8-fold (Leucophor). CONCLUSION: These results have clear applications for the use of ChchSNPV-TF1 as a biological insecticide in control programs against C.chalcites in the Canary Islands. c � 2013 Society of Chemical Industry Supporting information may be found in the online version of this article.
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application of juvenile hormone analogue and Optical brightener technologies to the production of spodoptera frugiperda multiple nucleopolyhedrovirus
Proceedings of the IOBC WPRS Working Group "Insect Pathogens and Insect Parasitic Nematodes" and COST Action 862 "Bacterial Toxins for Insect Control", 2009Co-Authors: Rodrigo Lasa, I Moreno, N Crickmore, I Glazer, R. U. Ehlers, Jurg Enkerli, Trevor Williams, Primitivo Caballero, M Lopezferber, Cezary TkaczukAbstract:Final instar larvae of Spodoptera frugiperda grew to a maximum weight of 622 ± 13 mg on diet treated with 1% piriproxyfen, a juvenile horrnone analogue (JHA). or 695 ± 17 mg on diet treated with 1% fenoxycarb, both of which were significantly greater weights than observed in larvae that developed on untreated diet (512 ± 9 mg). Virus mortality in insects inoculated with SfMNPV occlusion bodies (OBs) was approximately 50% in all treatments, reflecting the resistance of late instar S. frugiperda larvae to infection. However, JHA treatment did not result in a significant increases in the total OB yield, or OBs per mg larval weight, compared to untreated infected insects. We deterrnined whether resistance to infection could be overcome by inoculation with mixtures of OBs and Optical Brighteners. Potentiation of OB activity was >2500-fold in mixtures with 1% Leukophor AP or Blankophor BA, or >15-fold in mixtures with 0.1 % of either brightener, compared to SfMNPV OBs alone. We conclude that SfMNPV production was 110t increased in JHA treated larvae because the JHA did not result in a supernumerary instar in S. frugiperda. However, Optical Brighteners were highly effective in overcoming developmental resistance to infection in this species.
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Optical Brighteners do not influence covert baculovirus infection of Spodoptera frugiperda.
Applied and Environmental Microbiology, 2005Co-Authors: Anamabel Martinez, Miguel López-ferber, Trevor Williams, Primitivo CaballeroAbstract:Covert infection with Spodoptera frugiperda multiple nucleopolyhedrovirus, detected by reverse transcription-PCR of virus gene transcripts (ie-0 and polh), was not significantly affected by the presence of an Optical brightener (Tinopal UNPA-GX), indicating no change in virus virulence. Detection of the covert infection was dependent on insect life stage and the viral mRNA used for diagnosis.
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formulation with an Optical brightener does not increase probability of developing resistance to spodoptera frugiperda nucleopolyhedrovirus in the laboratory
Journal of Economic Entomology, 2004Co-Authors: Anamabel Martinez, Maider Villanueva, Nagore Miralles, Ivan San Martin, Estibaliz Lopez, Primitivo Caballero, Trevor WilliamsAbstract:Abstract Stilbene-derived Optical Brighteners can markedly enhance the insecticidal activity of certain baculoviruses. We evaluated the influence of an Optical brightener on the rate at which Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) developed resistance to nucleopolyhedrovirus (SfMNPV). Two laboratory colonies of S. frugiperda were inoculated with an LC50 of SfMNPV, in the absence or presence of the Optical brightener Tinopal LPW (0.1%), over a period of two and 11 generations, in the first and second experiment, respectively. Compared with the initial susceptibility of the insect colony, resistance ratios of 11- and 12-fold were observed after two generations of treatment with SfMNPV + Tinopal LPW and SfMNPV alone. Similar, but variable degrees of resistance were observed in the long-term experiment with resistance ratios of 8- to 35-fold after seven to 11 generations. The presence of Tinopal LPW alone, or in mixtures with SfMNPV, did not cause any systematic change in insect resistanc...
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Formulation with an Optical Brightener Does Not Increase Probability of Developing Resistance to Spodoptera frugiperda Nucleopolyhedrovirus in the Laboratory
Journal of Economic Entomology, 2004Co-Authors: Anamabel Martinez, Maider Villanueva, Nagore Miralles, Estibaliz Lopez, Primitivo Caballero, Ivan San Martín, Trevor WilliamsAbstract:Stilbene-derived Optical Brighteners can markedly enhance the insecticidal activity of certain baculoviruses. We evaluated the influence of an Optical brightener on the rate at which Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) developed resistance to nucleopolyhedrovirus (SfMNPV). Two laboratory colonies of S. frugiperda were inoculated with an LC50 of SfMNPV, in the absence or presence of the Optical brightener Tinopal LPW (0.1%), over a period of two and 11 generations, in the first and second experiment, respectively. Compared with the initial susceptibility of the insect colony, resistance ratios of 11- and 12-fold were observed after two generations of treatment with SfMNPV + Tinopal LPW and SfMNPV alone. Similar, but variable degrees of resistance were observed in the long-term experiment with resistance ratios of 8- to 35-fold after seven to 11 generations. The presence of Tinopal LPW alone, or in mixtures with SfMNPV, did not cause any systematic change in insect resistance in either experiment. At the end of the long-term experiment, debilitating effects on pupal weight, adult fecundity, and longevity were observed in the insects exposed to Tinopal LPW alone or in mixtures with SfMNPV, but the pattern of such effects among treatments differed in each generation. We conclude that Optical Brighteners are unlikely to affect the rate of development of resistance to nucleopolyhedroviruses applied as biological insecticides.
Alex Wilkie - One of the best experts on this subject based on the ideXlab platform.
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an analytic model for full spectral sky dome radiance
International Conference on Computer Graphics and Interactive Techniques, 2012Co-Authors: Lukas Hosek, Alex WilkieAbstract:We present a physically-based analytical model of the daytime sky. Based on the results of a first-principles brute force simulation of radiative transfer in the atmosphere, we use the same general approach of fitting basis function coefficients to radiance data as the Perez and Preetham models do. However, we make several modifications to this process, which together significantly improve the rendition of sunsets and high atmospheric turbidity setups -- known weak points of the Preetham model. Additionally, our model accounts for ground albedo, and handles each spectral component independently. The latter property makes it easily extensible to the near ultraviolet range of the spectrum, so that the daylight appearance of surfaces that include Optical Brighteners can be properly predicted. Due to its similar mathematical properties, the new model can be used as a drop-in replacement of the Preetham model.
Lukas Hosek - One of the best experts on this subject based on the ideXlab platform.
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To appear in ACM TOG 31(4). An Analytic Model for Full Spectral Sky-Dome Radiance
2013Co-Authors: Lukas Hosek, Alexander WilkieAbstract:We present a physically-based analytical model of the daytime sky. Based on the results of a first-principles brute force simulation of radiative transfer in the atmosphere, we use the same general approach of fitting basis function coefficients to radiance data as the Perez and Preetham models do. However, we make several modifications to this process, which together significantly improve the rendition of sunsets and high atmospheric turbidity setups – known weak points of the Preetham model. Additionally, our model accounts for ground albedo, and handles each spectral component independently. The latter property makes it easily extensible to the near ultraviolet range of the spectrum, so that the daylight appearance of surfaces that include Optical Brighteners can be properly predicted. Due to its similar mathematical properties, the new model can be used as a drop-in replacement of the Preetham model
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an analytic model for full spectral sky dome radiance
International Conference on Computer Graphics and Interactive Techniques, 2012Co-Authors: Lukas Hosek, Alex WilkieAbstract:We present a physically-based analytical model of the daytime sky. Based on the results of a first-principles brute force simulation of radiative transfer in the atmosphere, we use the same general approach of fitting basis function coefficients to radiance data as the Perez and Preetham models do. However, we make several modifications to this process, which together significantly improve the rendition of sunsets and high atmospheric turbidity setups -- known weak points of the Preetham model. Additionally, our model accounts for ground albedo, and handles each spectral component independently. The latter property makes it easily extensible to the near ultraviolet range of the spectrum, so that the daylight appearance of surfaces that include Optical Brighteners can be properly predicted. Due to its similar mathematical properties, the new model can be used as a drop-in replacement of the Preetham model.
Anamabel Martinez - One of the best experts on this subject based on the ideXlab platform.
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Effects of Optical Brighteners used in biopesticide formulations on crops: reflectance, stomatal conductance, photosynthesis, and growth.
Communications in agricultural and applied biological sciences, 2009Co-Authors: Anamabel Martinez, Velasco S, Méndez A, José-isaac Figueroa, Cárdenas-navarro R, Samuel PinedaAbstract:SUMMARY Optical Brighteners have attracted interest as adjuvant’s in baculovirus-based biological insecticides due to their ability enhance the insecticidal properties of these viruses and protect virus particles from the degrading effects of ultraviolet (UV) radiation. The effects of two types of Optical Brighteners, Tinopal CBS (a distyryl-biphenyl derivative) and Tinopal C1101 (an ethenediyl benzenesulfonic derivative) at 1 or 3% (wt./vol.), on growth of different crOPs [maize, Zea mays L. (var. HY-311), sorghum, Sorghum vulgare Pers. (var. Silo), tomato, Lycopersicum esculentum L. (var. Floradade IT), or pepper, Capsicum annum L. (var. Cal Won 300)] were examined after once a week application during four weeks. Both compounds significantly affected the growth of maize plants, whereas sorghum plants were affected only at the highest concentration of Tinopal C1101. Neither brightener had negative effects on tomato or peppers plants. Both compounds increased the percentage of reflectance of maize and tomato leaves when analyzed using laboratory and field spectrophotometers. A greenhouse experiment involving single application of 1 and 3% Tinopal C1101 indicated that the stomatal conductance and photosynthetic rate of maize and tomato plants were not significantly affected. We conclude that the effects of Optical Brighteners on plant growth are more likely to be influenced by differences between plant species than differences between brightener compounds.
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Optical Brighteners do not influence covert baculovirus infection of Spodoptera frugiperda.
Applied and Environmental Microbiology, 2005Co-Authors: Anamabel Martinez, Miguel López-ferber, Trevor Williams, Primitivo CaballeroAbstract:Covert infection with Spodoptera frugiperda multiple nucleopolyhedrovirus, detected by reverse transcription-PCR of virus gene transcripts (ie-0 and polh), was not significantly affected by the presence of an Optical brightener (Tinopal UNPA-GX), indicating no change in virus virulence. Detection of the covert infection was dependent on insect life stage and the viral mRNA used for diagnosis.
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formulation with an Optical brightener does not increase probability of developing resistance to spodoptera frugiperda nucleopolyhedrovirus in the laboratory
Journal of Economic Entomology, 2004Co-Authors: Anamabel Martinez, Maider Villanueva, Nagore Miralles, Ivan San Martin, Estibaliz Lopez, Primitivo Caballero, Trevor WilliamsAbstract:Abstract Stilbene-derived Optical Brighteners can markedly enhance the insecticidal activity of certain baculoviruses. We evaluated the influence of an Optical brightener on the rate at which Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) developed resistance to nucleopolyhedrovirus (SfMNPV). Two laboratory colonies of S. frugiperda were inoculated with an LC50 of SfMNPV, in the absence or presence of the Optical brightener Tinopal LPW (0.1%), over a period of two and 11 generations, in the first and second experiment, respectively. Compared with the initial susceptibility of the insect colony, resistance ratios of 11- and 12-fold were observed after two generations of treatment with SfMNPV + Tinopal LPW and SfMNPV alone. Similar, but variable degrees of resistance were observed in the long-term experiment with resistance ratios of 8- to 35-fold after seven to 11 generations. The presence of Tinopal LPW alone, or in mixtures with SfMNPV, did not cause any systematic change in insect resistanc...
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Formulation with an Optical Brightener Does Not Increase Probability of Developing Resistance to Spodoptera frugiperda Nucleopolyhedrovirus in the Laboratory
Journal of Economic Entomology, 2004Co-Authors: Anamabel Martinez, Maider Villanueva, Nagore Miralles, Estibaliz Lopez, Primitivo Caballero, Ivan San Martín, Trevor WilliamsAbstract:Stilbene-derived Optical Brighteners can markedly enhance the insecticidal activity of certain baculoviruses. We evaluated the influence of an Optical brightener on the rate at which Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) developed resistance to nucleopolyhedrovirus (SfMNPV). Two laboratory colonies of S. frugiperda were inoculated with an LC50 of SfMNPV, in the absence or presence of the Optical brightener Tinopal LPW (0.1%), over a period of two and 11 generations, in the first and second experiment, respectively. Compared with the initial susceptibility of the insect colony, resistance ratios of 11- and 12-fold were observed after two generations of treatment with SfMNPV + Tinopal LPW and SfMNPV alone. Similar, but variable degrees of resistance were observed in the long-term experiment with resistance ratios of 8- to 35-fold after seven to 11 generations. The presence of Tinopal LPW alone, or in mixtures with SfMNPV, did not cause any systematic change in insect resistance in either experiment. At the end of the long-term experiment, debilitating effects on pupal weight, adult fecundity, and longevity were observed in the insects exposed to Tinopal LPW alone or in mixtures with SfMNPV, but the pattern of such effects among treatments differed in each generation. We conclude that Optical Brighteners are unlikely to affect the rate of development of resistance to nucleopolyhedroviruses applied as biological insecticides.
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effects of an Optical brightener on the development body weight and sex ratio of spodoptera frugiperda lepidoptera noctuidae
Biocontrol Science and Technology, 2004Co-Authors: Anamabel Martinez, Primitivo Caballero, Trevor WilliamsAbstract:The incorporation of stilbene-derived Optical Brighteners into baculovirus formulations can substantially enhance virus infectivity and persistence of inoculum in the field. We evaluated the effect of the Optical brightener Tinopal UNPA-GX (Sigma Chemical Co.) on the weight, development time, adult emergence and sex ratio of the principal pest of maize in the Americas, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae). Tinopal UNPA-GX was incorporated into semi-synthetic diet at a final concentration of 0.1 or 0.05% (w/v) and larvae of S. frugiperda were individually reared on the Tinopal-treated or an untreated control diet. In both Tinopal treatments, the weights of larvae and pupae were significantly reduced by up to 36 and 13%, respectively. The duration of larval development was increased by up to 30% compared to the controls. Adult emergence was high in all treatments (≈90%) and was not affected by the presence of Tinopal in the diet. Significant differences in the proportion of adult fem...