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Çakmak T, Simón O, Kaydan MB, Tange DA, González Rodríguez AM, Piedra-Buena Díaz A, Caballero Murillo P, Hernández Suárez E. Effects of several UV-protective substances on the persistence of the insecticidal activity of the Alphabaculovirus of Chrysodeixis chalcites (ChchNPV-TF1) on banana (Musa acuminata, Musaceae, Colla) under laboratory and open-field conditions. PLoS One 2021; 16:e0250217. [PMID: 33979364 PMCID: PMC8115783 DOI: 10.1371/journal.pone.0250217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 04/02/2021] [Indexed: 11/18/2022] Open
Abstract
Alphabaculovirus of Chrysodeixis chalcites (ChchNPV-TF1) has been investigated as a useful bioinsecticide against C. chalcites (Esper) (Lepidoptera: Noctuidae) in banana crops. This study investigated the effects of several substances on the persistence of ChchNPV-TF1 under field conditions in the Canary Islands. Natural photoprotective substances, such as moringa, cacao, green tea, benzopurpurine, charcoal, iron dioxide, benzimidazole, kaolinite, and bentonite, were first evaluated under laboratory conditions using a Crosslinker as UV light source at 200 J/cm2. The photoprotective substances were divided into three groups: low protection (0–8%; kaolinite), intermediate protection (48–62%; green tea, moringa, bentonite and cacao) and high protection (87–100%; charcoal, iron ioxide). Benzopurpurine and benzimidazole did not provide any photoprotective effects. Two of the substances that yielded the best results, 1% cacao and 1% charcoal, were selected for the open-field experiment in a banana plantation. The persistence of ChchNPV-TF1 OBs (occlusion bodies) on leaf surfaces with sunlight exposure was analysed by comparing the initial mortality of 2nd instar C. chalcites larvae with the mortality observed at various intervals postapplication. The mortality rates decreased over time in all treatments and were always higher in the UV-protective substance-treated parcels. The 1% charcoal treatment exhibited the highest protection in both the laboratory and field experiments. No specific interference of UV-protective substances on the maximum photochemical efficiency of banana plants was observed under field conditions.
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Affiliation(s)
- Taylan Çakmak
- Unidad de Protección Vegetal, Instituto Canario de Investigaciones Agrarias (ICIA), Valle de Guerra, Tenerife, Spain
| | - Oihane Simón
- Bioinsecticidas Microbianos, Institute for Multidisciplinary Research in Applied Biology (IMAB), Universidad Pública de Navarra (UPNa), Mutilva, Navarra, Spain
| | - Mehmet Bora Kaydan
- Biotechnology Application and Research Centre, Çukurova University, Adana, Turkey
- İmamoğlu Vocational School, Çukurova University, Adana, Turkey
| | - Denis Achiri Tange
- Faculty of Agriculture, Department of Plant Protection Balcali, Çukurova University, Adana, Turkey
| | - Agueda Mª. González Rodríguez
- Departamento de Botánica, Ecología y Fisiología Vegetal, Universidad de La Laguna, San Cristóbal de La Laguna, Tenerife, Spain
| | - Ana Piedra-Buena Díaz
- Unidad de Protección Vegetal, Instituto Canario de Investigaciones Agrarias (ICIA), Valle de Guerra, Tenerife, Spain
- * E-mail:
| | - Primitivo Caballero Murillo
- Bioinsecticidas Microbianos, Institute for Multidisciplinary Research in Applied Biology (IMAB), Universidad Pública de Navarra (UPNa), Mutilva, Navarra, Spain
| | - Estrella Hernández Suárez
- Unidad de Protección Vegetal, Instituto Canario de Investigaciones Agrarias (ICIA), Valle de Guerra, Tenerife, Spain
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Tang Q, Chen F, Wu P, Qiu L, Chen H, Chen K, Li G. BmNPV infection correlates with the enhancement of the resistance of Bombyx mori cells to UV radiation. Arch Insect Biochem Physiol 2019; 102:e21598. [PMID: 31290186 DOI: 10.1002/arch.21598] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 05/31/2019] [Accepted: 06/18/2019] [Indexed: 06/09/2023]
Abstract
At present, the effect of ultraviolet (UV) radiation on the interaction between Bombyx mori nucleopolyhedrovirus (BmNPV) and host remains unclear. In the current study, UV treatment significantly reduced the activity of BmNPV budded viruses (BVs), and UV-damaged BmN cells were not conducive to BmNPV proliferation. BmNPV infection significantly reduced the viability of host cells, but increased the viability of high-dose UV-treated host cells. Furthermore, the quantitative reverse-transcription PCR (qPCR) results suggested that BmNPV and Bombyx mori might mutually use the same DNA repair proteins for repairing UV-induced damage and BmNPV infection promote the ability of host cells to repair UV-induced damage.
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Affiliation(s)
- Qi Tang
- Institute of Life Sciences, Jiangsu University, Zhenjiang, China
| | - Fangying Chen
- Institute of Life Sciences, Jiangsu University, Zhenjiang, China
| | - Peng Wu
- Institute of Life Sciences, Jiangsu University, Zhenjiang, China
| | - Lipeng Qiu
- Institute of Life Sciences, Jiangsu University, Zhenjiang, China
| | - Huiqing Chen
- Institute of Life Sciences, Jiangsu University, Zhenjiang, China
| | - Keping Chen
- Institute of Life Sciences, Jiangsu University, Zhenjiang, China
| | - Guohui Li
- Institute of Life Sciences, Jiangsu University, Zhenjiang, China
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Akhanaev YB, Belousova IA, Ershov NI, Nakai M, Martemyanov VV, Glupov VV. Comparison of tolerance to sunlight between spatially distant and genetically different strains of Lymantria dispar nucleopolyhedrovirus. PLoS One 2017; 12:e0189992. [PMID: 29261790 PMCID: PMC5738102 DOI: 10.1371/journal.pone.0189992] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 12/06/2017] [Indexed: 11/18/2022] Open
Abstract
Baculoviruses are a family of insect-specific pathogenic viruses can persist outside for long periods through the formation of occlusion bodies. In spite of this ability, the UV of sunlight is an essential factor that limits the survival of baculoviruses outside the host. In the current study, we compared the UV tolerance of two strains of Lymantria dispar multiple nucleopolyhedrovirus (LdMNPV), which were isolated in spatially different regions (LdMNPV-27/0 in Western Siberia (Russia) and LdMNPV-45/0 in North America (USA)) and dramatically differ in their potency. We exposed the studied strains to sunlight in an open area for 0.25, 0.5, 1, and 2 hours and later perorally inoculated host larvae with the same doses of virus (5x105) and with doses leading to same effect (LD90). We observed that strain LdMNPV-45/0, which previously showed high virulence against L. dispar larvae, was more sensitive to UV irradiation (estimated as the relative rate of inactivation (r, h -1) and as the half-life of the virus (τ1/2, h)) compared to LdMNPV-27/0. Exposure to sunlight induced a significant delay of LdMNPV-45/0-induced pathogenesis already after 0.25 h of sunlight exposure, while for LdMNPV-27/0 this delay was occurred only after 2 h exposure in spite of used concentrations. We also compared the sequences of the main structural proteins of the studied strains as UV light contributes not only to genome damage in viruses but also to structural protein damage. The most prominent genetic difference between the structural proteins of the strains was related to the loss of the virus enhancin factor-1 (vef-1) gene in the LdMNPV-27/0 strain. Thus initially highly potent viral strain (such as LdMNPV-45/0) is not recommend to use in the regions (or forest stand density) with high UV load. The role of virus enhancin factor-1 in baculovirus tolerance to UV needs for following studies.
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Affiliation(s)
- Yuriy B. Akhanaev
- Laboratory of Insect Pathology, Institute of Systematics and Ecology of Animals SB RAS, Novosibirsk, Russia
| | - Irina A. Belousova
- Laboratory of ecological parasitology, Institute of Systematics and Ecology of Animals SB RAS, Novosibirsk, Russia
- Institute of Biology, Irkutsk State University, Irkutsk, Russia
| | - Nikita I. Ershov
- Molecular Genetics Department, Institute of Cytology and Genetics SB RAS, Novosibirsk, Russia
| | - Madoka Nakai
- Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan
| | - Vyacheslav V. Martemyanov
- Laboratory of ecological parasitology, Institute of Systematics and Ecology of Animals SB RAS, Novosibirsk, Russia
- Biological Institute, National Research Tomsk State University, Tomsk, Russia
- * E-mail:
| | - Viktor V. Glupov
- Laboratory of Insect Pathology, Institute of Systematics and Ecology of Animals SB RAS, Novosibirsk, Russia
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Dwi Sutanto K, El Salamouny S, Tufail M, Ghulam Rasool K, Sukirno S, Shepard M, Shapiro M, Saad Aldawood A. Evaluation of Natural Additives to Enhance the Persistence of Spodoptera littoralis (Lepidoptera: Noctuidae) Nucleopolyhedrovirus (SpliMNPV) Under Field Conditions in Saudi Arabia. J Econ Entomol 2017; 110:924-930. [PMID: 28460121 DOI: 10.1093/jee/tox085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Indexed: 06/07/2023]
Abstract
Nucleopolyhedrovirus is an effective biocontrol agent but for its biggest disadvantage of short persistence under sunlight conditions. In this study, 10 plant extracts were evaluated as ultraviolet (UV) protectants to improve the persistence of Spodoptera littoralis multiple-embedded nucleopolyhedrovirus (SpliMNPV) against cotton leafworm (Spodoptera littoralis Boisduval). In the primary lab screening test, 5 out of 10 additives (cloves, henna, green tea, pomegranate, and grape extracts) presented a high rate of virus protection with original activity remaining (OAR) percentage of 100%, 97%, 91%, 90.6%, and 77%, respectively, when used at a concentration of 1% and exposed to UVB for a period of 1 h. A secondary screening was then performed with these best five extracts at a concentration of 0.5% and for an exposure timing of 5 h to UVB. Among these, clove and henna that showed highest protection with OAR values of 96.6% and 76.5%, respectively, were selected for the field trials. When applied on cabbage in the field during sunny summer conditions, clove and henna extracts enhanced the persistence of SpliMNPV by twofold. These findings are encouraging to be applied in the field studies.
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Affiliation(s)
- Koko Dwi Sutanto
- Economic Entomology Research Unit (EERU), Department of Plant Protection, College of Food and Agriculture Sciences, King Saud University, Riyadh 11451, Saudi Arabia (; ; ; ; ; )
| | - Said El Salamouny
- Economic Entomology Research Unit (EERU), Department of Plant Protection, College of Food and Agriculture Sciences, King Saud University, Riyadh 11451, Saudi Arabia ( ; ; ; ; ; )
- Department of Economic Entomology and Pesticides, Faculty of Agriculture, Cairo University, Giza, Egypt
| | - Muhammad Tufail
- Economic Entomology Research Unit (EERU), Department of Plant Protection, College of Food and Agriculture Sciences, King Saud University, Riyadh 11451, Saudi Arabia ( ; ; ; ; ; )
- Organization of Advanced Science and Technology, Kobe University, Japan
- Corresponding author, e-mail:
| | - Khawaja Ghulam Rasool
- Economic Entomology Research Unit (EERU), Department of Plant Protection, College of Food and Agriculture Sciences, King Saud University, Riyadh 11451, Saudi Arabia (; ; ; ; ; )
| | - Sukirno Sukirno
- Economic Entomology Research Unit (EERU), Department of Plant Protection, College of Food and Agriculture Sciences, King Saud University, Riyadh 11451, Saudi Arabia ( ; ; ; ; ; )
- Entomology Laboratory, Faculty Biology, Gadjah Mada University, Yogyakarta 55281, Indonesia
| | - Merle Shepard
- Coastal Research and Educational Center, Clemson University, 2700 Savannah Highway, Charleston, SC (; )
| | - Martin Shapiro
- Coastal Research and Educational Center, Clemson University, 2700 Savannah Highway, Charleston, SC (; )
| | - Abdulrahman Saad Aldawood
- Economic Entomology Research Unit (EERU), Department of Plant Protection, College of Food and Agriculture Sciences, King Saud University, Riyadh 11451, Saudi Arabia (; ; ; ; ; )
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Kolosov AV, Pugachev VG, Anan'ko GG, Totmenina OD, Kliachko NL, Levashev PA, Kosogova TA. [Design of the composition of baculovirus agents]. Vopr Virusol 2011; 56:40-44. [PMID: 22171478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The ability of 30 compounds to protect infection bacteria and baculoviruses from the damaging effect of ultraviolet (UV) irradiation was investigated. For this B. thuringiensis var. israelensis spores and gypsy moth (Lymantria dispar L.) nuclear polyhedrosis virus were mixed with different components and exposed to UV irradiation at 0.25 WI cm2 for 60 min. Then spore viability and viral pathogenicity were studied in third instar gypsy moth larvae. The composition comprising sodium alginate, albumin, and ascorbic acid ensured the most effective protection of the viruses and bacteria. These components were shown to provide protection from exposure to UV irradiation even at a low concentration. Their incorporation into biopesticides will assist in enhancing the efficiency of their use.
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El-Salamouny S, Ranwala D, Shapiro M, Shepard BM, Farrar RR. Tea, coffee, and cocoa as ultraviolet radiation protectants for the beet armyworm nucleopolyhedrovirus. J Econ Entomol 2009; 102:1767-1773. [PMID: 19886440 DOI: 10.1603/029.102.0506] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The addition of 1% (wt:vol) aqueous extracts of cocoa (Theobroma cacao L.) (Malvales: Malvaceae), coffee (Coffea arabica L.) (Gentianales: Rubiaceae), and green and black tea (Camellia sinensis L.) (Ericales: Theaceae) provided excellent UV radiation protection for the beet armyworm, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae), nucleopolyhedrovirus under laboratory conditions. Aqueous extracts of coffee, green tea, and black tea at 0.5% provided 85-100% UV protection, whereas cocoa provided 50% UV protection. Epigallocatechin gallate (EGCG), a component of green tea, and caffeine, a component of tea and coffee, also were tested as UV protectants. Both compounds were ineffective when tested alone. When EGCG and caffeine were combined, UV protection increased in a synergistic manner, but <35% of the original virus activity was maintained. This study demonstrated that coffee was comparable to green tea and black tea as a UV protectant. Further studies should be conducted to optimize their use in biopesticide formulations.
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Affiliation(s)
- S El-Salamouny
- Clemson University Coastal Research & Education Center, 2700 Savannah Highway, Charleston, SC 29414, USA
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Mondragón G, Pineda S, Martínez A, Martínez AM. Optical brightener Tinopal C1101 as an ultraviolet protectant for a nucleopolyhedrovirus. Commun Agric Appl Biol Sci 2007; 72:543-547. [PMID: 18399486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Baculoviruses are arthropod-specific viruses currently used as biological insecticides in several countries of the world. One important factor limiting the efficacy of these bioinsecticides is related to the inactivation of the virus by solar ultraviolet (UV) radiation. This has motivated studies focused on the use of optical brightener compounds that can protect the virus from UV inactivation. The effects of the optical brightener Tinopal C1101 (ethenedyl benzenesulfonic derivative) on the persistance of a nucleopolyhedrovirus (SfMNPV) was quantified in third instar Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), the principal pest of maize in the Americas. For this, laboratory studies were performed to determine the relationship between virus concentrations and radiation-caused inactivation of SfMNPV alone or in mixtures with 1.25 or 0.1% (vol/vol) Tinopal C1101 using a UV system [radiation was provided by a 15 W UV tube (emission maxima at 312 nm)]. SfMNPV alone was more sensitive to UV than in mixtures with 1.25 or 0.1% Tinopal C1101. For instance, at concentrations of 2.22 x 10(8) and 2.75 x 10(6) occlusion bodies (OBs)/ml, SfMNPV alone-caused mortality was reduced from 88 and 44% (without UV radiation) to 0%, in both cases, after 30 and 15 min exposure to the UV tube, respectively. In contrast, the incorporation of 1.25% Tinopal C1101 into the SfMNPV inoculum at 2.22 x 10(8) and 2.75 x 10(6) OBs/ml caused a mortality of 86.6 and 96.6% after 240 min, respectively. UV-caused inactivation of SfMNPV was directly related to the optical brightener concentration. We conclude that optical brighteners are likely to represent valuable components of nucleopolyhedrovirus formulations.
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Affiliation(s)
- G Mondragón
- Instituto de Investigaciones Agropecuarias y Forestales Universidad Michoacana de San Nicolds de Hidalgo, Km. 9.5 Carretera Morelia-Zinapécuaro, 58880 Tarímbaro, Michoacán, Mexico
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McIntosh AH, Grasela JJ, Lua L, Braunagel SC. Demonstration of the protective effects of fluorescent proteins in baculoviruses exposed to ultraviolet light inactivation. J Insect Sci 2004; 4:31. [PMID: 15861246 PMCID: PMC1081559 DOI: 10.1093/jis/4.1.31] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2004] [Accepted: 07/17/2004] [Indexed: 05/24/2023]
Abstract
Autographa californica multiple nucleopolyhedrovirus (AcMNPV) recombinants, namely AcRFP produced by fusion of the red fluorescent protein (RFP) gene with the polyhedrin gene, and a recombinant (pAcUW21-23GFP) carrying the green fluorescent protein (GFP) in its viral envelope, were evaluated for their resistance to inactivation by ultraviolet light. AcRFP recombinants produced incomplete polyhedra with low infectivity for Trichoplusia ni larvae, whereas AcuW21-23GFP produced normal polyhedra with high infectivity. Electron microscopy of AcRFP CL14 showed the incorporation of very few viral particles into polyhedrin matrix protein material. The LC50 for AcuW21-23GFP was 0.10 occlusion bodies/mm2, whereas the LC50 values for several AcRFP recombinants ranged from 20 to 329 occlusion bodies/mm2. When both the RFP and GFP recombinants were exposed to ultraviolet light (UV-B 280-320 nm), the results support the conclusion that these fluorescent proteins afford some protection against its damaging effects.
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Affiliation(s)
- A H McIntosh
- USDA, Agricultural Research Service, Biological Control of Insects Research Laboratory, Columbia, Missouri 65203, USA.
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Shapiro M, Farrar RR, Domek J, Javaid I. Effects of virus concentration and ultraviolet irradiation on the activity of corn earworm and beet armyworm (Lepidoptera: Noctuidae) nucleopolyhedroviruses. J Econ Entomol 2002; 95:243-249. [PMID: 12019996 DOI: 10.1603/0022-0493-95.2.243] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Laboratory studies were initiated to determine the relationship between virus concentration and radiation-caused inactivation of NPVs from Helicoverpa zea (HzSNPV) and Spodoptera exigua (SeMNPV). In the laboratory, a UV-B/UV-A system was used for inactivation studies. For both viruses inactivation was dependent upon both length of UV exposure and virus concentration. At all virus concentrations HzSNPV was more sensitive to UV than SeMNPV. In the field HzSNPV was used and virus persistence was significantly affected by virus concentration (i.e., inactivation was inversely related to virus concentration).
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Affiliation(s)
- Martin Shapiro
- Insect Biocontrol Laboratory, USDA-ARS, Henry A. Wallace Agricultural Research Center, Beltsville, MD 20705, USA.
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Martin S, Domek J. Relative effects of ultraviolet and visible light on the activities of corn earworm and beet armyworm (Lepidoptera: Noctuidae) nucleopolyhedroviruses. J Econ Entomol 2002; 95:261-268. [PMID: 12019999 DOI: 10.1603/0022-0493-95.2.261] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Five different combinations of fluorescent tubes (UV-B/UV-B, UV-B/UV-A, UV-A/ UV-A, UV-B/White, White/White) were used to determine relative effects of UV and visible light on the nucleopolyhedroviruses (NPV) of Helicoverpa zea and Spodoptera exigua. For both viruses, the greatest inactivation occurred with exposure to UV-B radiation. Both virus concentration and radiation exposure time influenced the rate and degree of inactivation. In the case of the UV-A/UV-A and White/White combinations inactivation occurred only with the longest exposure (24 h) and the lowest virus concentration (0.747 PIB/mm2). The NPV from H. zea was found to be more sensitive to UV radiation than the NPV from S. exigua.
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Affiliation(s)
- Shapiro Martin
- Insect Biocontrol Laboratory, USDA-ARS, Henry A Wallace Agricultural Research Center-W, Beltsville, MD 20705, USA.
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Abstract
We compared the insecticidal activities of occluded and nonoccluded AfMNPV baculovirus obtained by dissolving the occlusion bodies (OB) with sodium carbonate. Droplet feeding and cotton leaf feeding bioassay techniques were used to determine the dose response against neonate Trichoplusia ni (Hübner) and loss of insecticidal activity when the virus was exposed to simulated sunlight from a xenon light source. Using droplet bioassays to determine a dose response, nonoccluded virus (NOV) was 20 times more active (LC(50) = 4.8 x 10(3) OB/ml, dissolved) than occluded virus (LC(50) = 9.6 x 10(4) OB/ml) when the samples remained wet. However, NOV lost activity when air dried before being tested by droplet (LC(50) > 1.0 x 10(6) OB/ml) or leaf feeding (LC(50) > 3.0 x 10(6) OB/ml) bioassays. Adding sucrose to NOV prevented the loss of insecticidal activity when samples were dried. The activity of NOV with 2% sucrose was similar to that of occluded virus samples, with or without sucrose, in both droplet feeding and leaf feeding assays. These results indicate that the OB protected the insecticidal activity of virions from the detrimental effects of drying. The OB also provided some protection from the detrimental effects of simulated sunlight (xenon) exposure. NOV samples exposed to xenon light had significantly greater loss of insecticidal activity than did similar samples of occluded virus. Without advancement in technologies, such as formulations, possible benefits of increased insecticidal activity from the use of nonoccluded virus is probably not sufficient to offset the rapid loss of activity due to drying or light exposure.
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Affiliation(s)
- R W Behle
- Bioactive Agents Research Unit, United States Department of Agriculture, Agricultural Research Center, National Center for Agricultural Utilization Research, Peoria, Illinois 61604, USA.
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