The Experts below are selected from a list of 732 Experts worldwide ranked by ideXlab platform
Trevor Williams - One of the best experts on this subject based on the ideXlab platform.
-
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.
-
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...
-
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...
-
Optical Brighteners Do Not Influence Covert Baculovirus Infection of
2004Co-Authors: Spodoptera Frugiperda, Trevor Williams, Primitivo CaballeroAbstract:Covert infection with Spodoptera frugiperdamultiple 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. Baculoviruses are virulent pathogens of insects, especially Lepidoptera, that form the basis for several biological insecti-cides (16). Baculovirus infections usually kill the host but may also survive as sublethal covert infections (17) and transmit themselves vertically, from parent to offspring (3, 10, 11, 14). Stilbene optical Brighteners increase the probability of virus infection by inhibiting chitin synthesis (1, 7), thus increasing the permeability of the midgut peritrophic membrane (21), and by reducing the rate of turnover of infected gut cells (22). We hypothesized that the optical brightener Tinopal UNPA-GX (Sigma, St. Louis, Mo.), administered in mixture
-
effects of an optical brightener and an abrasive on iridescent virus infection and development of aedes aegypti
Entomologia Experimentalis Et Applicata, 2003Co-Authors: Carlos F Marina, Juan I Arredondojimenez, Ildefonso Fernandezsalas, Jorge E Ibarra, Trevor WilliamsAbstract:The insecticidal properties of certain entomopathogenic viruses can be greatly improved in mixtures with substances that affect the integrity of the insect peritrophic membrane, particularly optical Brighteners. We aimed to determine the effect of an optical brightener, Blankophor BBH, and an abrasive compound, silicon carbide, alone and in mixtures, on the prevalence of patent and covert infection of Aedes aegypti (L.) (Diptera: Culicidae) by Invertebrate iridescent virus 6 (IIV-6) (Iridoviridae). The prevalence of patent infection by IIV-6 was < 1.5% in all treatments involving virus. Contrary to predictions, there were significantly fewer patent infections in virus treatments involving Blankophor with or without silicon carbide compared with controls. Covert infection of adults detected by insect bioassay was between 6.7 and 12.2%, although no significant differences were observed between treatments. Exposure to IIV-6 alone or silicon carbide alone did not significantly increase larval mortality compared to the controls, whereas exposure to Blankophor alone, or in any combination with IIV-6 or silicon carbide, clearly increased larval mortality. These effects did not carry-over to the pupal stage. Adult females emerged ∼ 1.5 days later than males. Compared to control insects, female development rate was extended by 11.4 and 12.6% in the treatments involving IIV-6 alone and silicon carbide alone, respectively. The sex ratio at adult emergence did not differ significantly between control insects and those of other treatments. These results support the hypothesis that the gut is unlikely to represent the principal point of infection of mosquito larvae by iridescent viruses.
Primitivo Caballero - One of the best experts on this subject based on the ideXlab platform.
-
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.
-
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.
-
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...
-
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...
-
Optical Brighteners Do Not Influence Covert Baculovirus Infection of
2004Co-Authors: Spodoptera Frugiperda, Trevor Williams, Primitivo CaballeroAbstract:Covert infection with Spodoptera frugiperdamultiple 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. Baculoviruses are virulent pathogens of insects, especially Lepidoptera, that form the basis for several biological insecti-cides (16). Baculovirus infections usually kill the host but may also survive as sublethal covert infections (17) and transmit themselves vertically, from parent to offspring (3, 10, 11, 14). Stilbene optical Brighteners increase the probability of virus infection by inhibiting chitin synthesis (1, 7), thus increasing the permeability of the midgut peritrophic membrane (21), and by reducing the rate of turnover of infected gut cells (22). We hypothesized that the optical brightener Tinopal UNPA-GX (Sigma, St. Louis, Mo.), administered in mixture
Edward M Dougherty - One of the best experts on this subject based on the ideXlab platform.
-
optical Brighteners provide baculovirus activity enhancement and uv radiation protection
Biological Control, 1996Co-Authors: Edward M Dougherty, K P GuthrieAbstract:Abstract Fluorescent Brighteners increase insect viral activity and provide protection against UV inactivation. The relative amount of viral UV protection has not previously been determined due to the dual nature of these compounds. In this study, two distinct viral–host systems, a nuclear polyhedrosis virus of the gypsy moth (Lymantria dispar) infecting its homologous host and a nuclear polyhedrosis virus of the alfalfa looper (Autographa californica) infecting the cabbage looper (Trichoplusia ni), were treated with various regimes of UV light from 0.5 to 120 min and fluorescent brightener 28 and were subsequently assayed with and without fluorescent brightener 28. A comparison of LC50s from the various treatments produced similar viral bioassay profiles in both systems. The fluorescent Brighteners protected insect viruses from UV inactivation and enhanced residual activity of active virus. For the gypsy moth virus, the enhancement was 214-fold for its homologous host and for theA. californicavirus, the enhancement was 41-fold forT. ni.
-
enhancement in activity of homologous and heterologous viruses against the gypsy moth lepidoptera lymantriidae by an optical brightener
Journal of Economic Entomology, 1994Co-Authors: Martin Shapiro, Edward M DoughertyAbstract:Addition of a selected stilbene optical brightener (Phorwite AR) to the gypsy moth cytoplasmic polyhedrosis virus reduced the LC50 from 1.21 × 105 polyhedral inclusion bodies (PIB) per ml to 1.40 × 102 PIE per ml in gypsy moth, Lymantria dispar (L.), larvae. The brightener also reduced the LT50 for this virus from 13.2d to 8.4 d (1 × 106 PIB per ml). Whereas the gypsy moth is not susceptible to such viruses as the Autographa nuclear polyhedrosis virus and the Amsacta entomopoxvirus, addition of Phorwite AR to suspensions of these viruses resulted in susceptibility.
Anamabel Martinez - One of the best experts on this subject based on the ideXlab platform.
-
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...
-
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...
-
Effect of optical Brighteners on the insecticidal activity of a nucleopolyhedrovirus in three instars of Spodoptera frugiperda
Entomologia Experimentalis Et Applicata, 2003Co-Authors: Anamabel Martinez, Oihane Simon, Trevor Williams, Primitivo CaballeroAbstract:Certain optical Brighteners are effective UV protectants, and can improve the insecticidal activity of baculoviruses. We evaluated the effect of 10 optical Brighteners, from four chemically different groups, on the insecticidal activity of a nucleopolyhedrovirus (SfMNPV) in third instar Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae). The most effective optical Brighteners were Blankophor BBH and Calcofluor M2R, both of which are stilbenes. The distyryl-biphenyl derivative, Tinopal CBS, had no effect, whereas the stilbenes, Blankophor CLE and Leucophor SAC and the styrylbenzenic derivative, Blankophor ER, resulted in a decrease in virus induced mortality compared to larvae infected with SfMNPV alone. Mixtures of SfMNPV + 0.1% Calcofluor M2R had relative potencies of 2.7, 6.5, and 61.6 in the second, third, and fourth instars, respectively. The mean time to death differed with instar, but was not affected by the addition of 0.1% Calcofluor M2R. Analysis of published studies indicated that the concentration of Calcofluor M2R-related stilbenes was positively correlated with the relative potency observed in mixtures with homologous NPVs. The average magnitude of optical brightener activity did not differ significantly between early instars of 10 species of Lepidoptera. We conclude that virus formulations containing optical Brighteners may be valuable for control of late instar lepidopteran pests.
-
Effects of optical Brighteners used in biopesticide formulations on the behavior of pollinators
Biological Control, 2000Co-Authors: Dave Goulson, Anamabel Martinez, William O. H. Hughes, Trevor WilliamsAbstract:A patent has been granted for the formulation of baculoviruses with stilbene-derived optical Brighteners, a group of compounds that absorb ultraviolet (UV) radiation and emit visible blue wavelengths. These compounds are being extensively tested for control of forest-feeding lepidopterous insects in North America; optical Brighteners may thus become a common ingredient in commercial baculovirus formulations in the near future. Many flower species use UV signals to attract insects and to direct them to the nectaries. We examined a possible consequence of field applications of optical Brighteners: their effects on the ability of pollinators to find and handle flowers. In field studies carried out in Mexico and the United Kingdom on three different flower species, application of dilute (0.1% or 1%) concentrations of the optical brightener Tinopal CBS reduced recruitment of bees to flowers. Bees that approached flowers were less likely to land and feed on flowers treated with Tinopal than on controls. On one plant species, Trifolium repens, the time taken for bees to handle inflorescences was longer following applications of Tinopal. It seems that this optical brightener may both reduce recruitment of insects to flowers and interfere with their ability to locate rewards. Field-scale applications could reduce pollination of crops, weeds, and wildflowers and adversely affect bee populations. These possibilities should be examined in more detail before widespread applications of these compounds to the environment are made. (C) 2000 Academic Press.
-
is it feasible to use optical brightener technology with a baculovirus bioinsecticide for resource poor maize farmers in mesoamerica
Biological Control, 2000Co-Authors: Anamabel Martinez, Dave Goulson, Ronald D Cave, Jason W Chapman, Primitivo Caballero, Trevor WilliamsAbstract:Stilbene-derived optical Brighteners greatly enhance the infectivity of a number of baculoviruses. This technology has been patented for use with insect pathogenic viruses in the United States and Canada. A baculovirus is currently being tested for its potential as a biological insecticide of Spodoptera frugiperda (Lepidoptera: Noctuidae), the principal insect pest of maize in Mesoamerica. A multiply embedded nucleopolyhedrovirus isolate originally from Nicaragua was bioassayed alone and in the presence of the optical brightener Tinopal LPW (1%), using second instar S. frugiperda larvae. The LC50 value of the virus alone was calculated at 82.1 polyhedral inclusion bodies (PIBs)/mm 2 of diet compared with 0.71 PIBs/mm 2 in the presence of Tinopal LPW. In contrast to other studies, the mean time to death of larvae exposed to virus and Tinopal LPW was significantly extended compared to larvae inoculated with virus alone. Analysis of the results of eight independent field trials in Mexico and Honduras revealed a significant positive relationship between log virus dose and percentage mortality observed in S. frugiperda larvae. Virus-induced mortality was approximately 50% at the highest application rate tested: 1000 larval equivalents (LE) of virus/ha. When the impact of parasitism was taken into account, larval mortality increased to 45.0‐90.7% in plots treated with virus at 250 LE/ha or more. A cost analysis indicated that approximately 60% pest control can be achieved as a conservative estimate with virus application and the action of parasitoids for the price of a chemical insecticide. Formulating the virus with an optical brightener appears to be an attractive option based on laboratory findings but requires field testing. The use of optical brightener technology will probably be feasible for maize growers in Mesoamerica only if it is highly effective at very low concentrations (F0.1%) or the volume of the virus application can be reduced. r 2000 Academic Press
K P Guthrie - One of the best experts on this subject based on the ideXlab platform.
-
optical Brighteners provide baculovirus activity enhancement and uv radiation protection
Biological Control, 1996Co-Authors: Edward M Dougherty, K P GuthrieAbstract:Abstract Fluorescent Brighteners increase insect viral activity and provide protection against UV inactivation. The relative amount of viral UV protection has not previously been determined due to the dual nature of these compounds. In this study, two distinct viral–host systems, a nuclear polyhedrosis virus of the gypsy moth (Lymantria dispar) infecting its homologous host and a nuclear polyhedrosis virus of the alfalfa looper (Autographa californica) infecting the cabbage looper (Trichoplusia ni), were treated with various regimes of UV light from 0.5 to 120 min and fluorescent brightener 28 and were subsequently assayed with and without fluorescent brightener 28. A comparison of LC50s from the various treatments produced similar viral bioassay profiles in both systems. The fluorescent Brighteners protected insect viruses from UV inactivation and enhanced residual activity of active virus. For the gypsy moth virus, the enhancement was 214-fold for its homologous host and for theA. californicavirus, the enhancement was 41-fold forT. ni.